HBjrm8AG

1Datbtrue Article Archive
2PEPTIDES BASICS
3
4GHRH (Growth Hormone Releasing Hormone) + GHRP (Growth Hormone Releasing Peptide) = 10 star GH Release (**********)
5
6GHRP (Growth Hormone Releasing Peptide aka Ghrelin-mimetic) = 3 star GH Release (***)
7
8GHRH (Growth Hormone Releasing Hormone) = 0 or 1 star GH Release (*)
9
10GHRPs (GHRP-6, GHRP-2, Hexarelin, Ipamorelin) are like cardiac shock paddles. You administer a GHRP and a pulse of GH is created. This is predictable and reliable across all normal people.
11
12GHRH creates no pulse. It only adds to what ever is happening naturally. If there is a pulse occurring then GHRH increases the GH release. If no pulse is occurring when GHRH is administered then it will have little effect on GH release.
13
14I can not speak for Dr. Crisler but he indicated that Sermorelin (GHRH) by itself was not very effective at raising IGF-1 levels. However when he added GHRP-6 with it at saturation dose (I believe administered together twice a day), IGF-1 levels increase by 1/3.
15
16This underscores the need for both a GHRH & a GHRP.
17
18IF you are 100% sure you have CJC-1295 (and the odds are against it) then because it is a long lasting GHRH (half-life measured in days) it will always be available which means during natural GH waves & troughs. So it behaves differently and its effectiveness in terms of absolute GH release is higher then the other forms of GHRH.
19
20CAVEAT - CJC-1295 raises base levels of GH not the pulses. It is possible that CJC-1295 never gives the somatotrophs sufficient time to reload stores of GH at the 100% level. Normally Somatostatin by stopping GH release activity gives the cells sufficient time to build up a big store of releasable GH. So CJC-1295 no matter how much GHRP you add may not be able to effect as strong a pulse as a GHRP + GHRH.
21
22There is no reason NOT to combine a GHRP such as GHRP-6 with your GHRH, no matter whether the form of GHRH is Sermorelin, modified GRF(1-29) or CJC-1295. There is only BIG benefit.
23
24On the flip side you can consistently and reliably effect GH pulsatile release with a GHRP alone. Without a GHRH the amplitude will not be synergistically higher. BUT it will be a strong pulse of GH release.
25
26One more quick point. An iu of synthetic GH is 333mcg of compound. Thats all. A unit of GH doesn't give the same effect across all normal people and even within a person there is variability.
27
28A far better measure is GH in plasma measured in many multiple intervals over a period of time. By sampling frequently you can determine the peak of GH in plasma and when it drops to baseline.
29
30You can then measure IGF-1 levels to determine the effect that THAT dosing had on increasing circulating levels.
31
32You can do the same thing with GHRH & GHRP.
33
34The problem people have is they are stuck on absolute levels of GH in circulation as being of paramount importance. It isn't.
35
36First it is free GH that is important. Anywhere from 10% to 90% may be bound at any given time with GH-Binding proteins or prolactin-binding proteins.
37
38Second it is pulsation that is important for growth not absolute levels. Pulses send communicative signals to the cells. GH is simply the ligand that gives form to the wave. GH has no other value except to be a part of a communication signal.
39
40The cells respond to this wave of GH by mediating events within the cell that are responsible for metabolism, protein synthesis, further ligand transcription & synthesis in the form of IGF-1 ...some of these signaling pathways in the cell carry messages to proliferate, differentiate or induce apoptosis . These intracellular pathways are common to many different tissue populations and respond to initiation from many different types of ligands binding to various receptors.
41
42This behavior is optimized by pulsation ...continuous GH desensitizes these pathways (and sends certain signals that are common to females to mediate certain events such as creation of specific liver enzymes)...
43
44So it is probable that I (and anyone who understands fully) could get more out of a small amount of GHRH + GHRP then someone who administers large amounts of GH. The validity of this statement is dependent on the use of other compounds...
45
46Finally to answer your question directly:
47
48I believe that if your CJC-1295 is modified GRF(1-29), coupled with GHRP-6, dosed as described you will achieve your goal of GH level (i.e. 4ius) and exceed both the quantity & quality of those growth optimizing events that THAT equivalent level of synthetic GH will be capable of mediating.
49BEGINNER: What should I use? ...and why? (GH Releasing System Simplified)
50
51Three Basic Hormones
52
53If you form a V w/ your fingers you have the basics for the GH releasing system modeled before you. One finger is a hormone called Growth Hormone Releasing Hormone (GHRH) and the other is the hormone Somatostatin.
54
55The bottom of the V is where both of those hormones converge. At that bottom we have somatotrophs (or somatotropes or Growth Hormone Releasing cells). These are cells that spend most of their time assembling Growth Hormone (GH) from pieces and storing it.
56
57So in this simple system we have three hormones. We have Growth Hormone Releasing Hormone (GHRH) which comes from the brain and contacts Growth Hormone Releasing Cells (Somatotrophs or somatotropes) and causes the cell to release some of the Growth Hormone (GH) it has made and stored. If we ask the cell to release GH all the time we end up with no storage of GH. As soon as some is made it is released. This is what I call GH bleed because you get a constant low flow or dribble of GH but no big pulse, or mass of GH.
58
59What causes GH release? The brain-derived hormone Growth Hormone Releasing Hormone (GHRH). So if GHRH is always free to act we end up with GH bleed.
60
61However the other brain-derived hormone Somatostatin functions as the "off switch". It also contacts the Growth Hormone Releasing Cell (Somatotroph) and instructs it not to release Growth Hormone (GH). If Somatostatin is present and GHRH is not then we will never have GH release. What we will have is plenty of time for the cells to make and store GH. If we could ever get Somatoststin to go away and GHRH to show up we'd have a big release or pulse of GH.
62
63As you can see both the "on switch" hormone Growth Hormone Releasing Hormone (GHRH) and the "off switch" hormone Somatostatin are necessary or we end up with a malfunctioning human being.
64
65You may wonder if we can limp by w/ just GH bleed. We can up until puberty when it is time to grow, develop and mature. Growth, development and maturity requires pulsatile GH (in conjunction with timed release of sex hormones).
66
67You may also wonder what happens if GHRH and Somatostatin are together at the bottom of the V at the same time. What does the cell do? The answer is that for the most part Somatostatin is stronger and GH will not be released.
68
69From this it is easy to see that a well-functioning GH releasing system depends on both GHRH & Somatostatin. Somatostatin to hold back release so enough GH can be made and then GHRH to cause a pulse of GH. Not only must these two brain-derived hormones which oppose each be active, they also must alternate with one another...GHRH release and a while later somatostatin and then a while later somatostatin retreats and GHRH is released again... this brings release of some of the GH mass that has been built up over the course of 3 hours in what looks like a pulse if graphed.
70
71Ghrelin (GHRPs) the 4th hormone in the GH Releasing System
72
73To be complete we need to add a fourth hormone to this system. One hormone Growth Hormone (GH) is the end-product hormone. It results from all of this activity. That leaves the other 3 hormones as hormones that determine how, when and how much GH will be released.
74
75If you replace the V you formed with your fingers with a Y, by using the same two fingers to form a V and now adding your long forearm, you have a very good model of the GH releasing system.
76
77The forearm extends to the stomach and that is where the hormone Ghrelin is made. Ghrelin is a hunger derived gut-hormone. It is capable of making its way to the pituitary where the GH releasing cells (somatotrophs) reside. Just like GHRH & Somatostatin it also can contact the cell. When it does it reduces Somatostatins effect. Ghrelin increases GH release. It does this in several ways -by encouraging the brain to release more GHRH, amplifying the effect of GHRH when it gets to the somatotroph, benefiting from GHRH being at the cell to amplify Ghrelin's own effect which is in part an increase in GH release and countering Somatostatin's stoppage effect at the cell.
78
79In fact Ghrelin can cause GH release all by itself even if Somatostatin is around. But Ghrelin makes the environment safe for GHRH to act and if GHRH acts when Ghrelin is there the result is what is called a synergistic GH release. Synergy means the amount is larger then each could have produced on its own. If Ghrelin would cause 5 units to be released and GHRH 2 units when you put them together synergy means the result is more then additive (5 + 2). The synergistic result may be 15 units. Why does synergy happen? GHRH and GHRP help each other... they make each other stronger. More complete fuller treatment of the topic available on the forum.
80
81Ghrelin is a natural hormone with effects besides GH release. Now a synthetic form of Ghrelin which primarily just effects GH release is what is known as Growth Hormone Releasing Peptides (GHRPs). These are man made and are capable of contacting the somatotrophs and causing GH release the same as Ghrelin.
82
83Originally they were called Secretagogues to include a few non-peptide structures as well. So Growth Hormone Releasing Peptides (GHRPs) may be thought of in our Y model as replacing Ghrelin. They differ from GHRH primarily in the color I chose. Consistently through most of my posts over the years I label them purple and GHRH I label green. Wake up! GHRPs are the 3rd hormone/peptide that effects GH release. Its presence at the somatotroph causes GH release on its own and with the naturally occurring "on switch" it amplifies GH release. By stopping somatostatin GH is released. Now GHRPs never result in GH bleed. The release they trigger is always a pulse that is over with within 3 hours.
84
85Will IGF-1 interfere with all of this?
86
87Not really IF you are supplying external GHRH and external GHRPs. IGF-1 primarily exerts negative feedback by increasing somatostatin release. Somatostatin is stopped by GHRPs. IGF-1 can also reduce release of natural GHRH from the brain. This is overcome by supplying external GHRH.
88
89What is CJC-1295, CJC-1293, GRF(1-29), Sermorelin and modified GRF(1-29)?
90
91In short they are all forms of GHRH (Growth Hormone Releasing Hormone).
92
93What are GHRP-6, GHRP-2, Ipamorelin, Hexarelin?
94
95In short they are all forms of GHRPs (Growth Hormone Releasing Peptides, Ghrelin-mimetics)
96
97How do I chose? What do I do? Step one: You NEVER know when somatostatin is going to act [Yes but Dat do I ever need to inject Somatostatin? No... not in our world...don't interupt please.] Again since you don't know if somatostatin is around you are rolling the dice by injecting GHRH. There will be zero GH release if somatostatin is around and only some if somatostatin is just starting up or just diminishing. Only if you are lucky to inject when somatostatin is gone will there be decent GH release. To overcome this, very large amounts say 2mg (2000mcg) are sometimes used. Injecting GHRH alone is not very effective.
98
99Step two: Choose a GHRP because it can always cause GH release on its own and make the environment safe for GHRH.
100
101Step three: Choose a GHRH to add to the GHRP because it will synergisticly amplify the GH pulse.
102
103Step four: Choose a dosing schedule. If once a day do it pre-bed. If twice a day then do it pre-bed and post workout (PWO). If three times a day do it pre-bed, PWO and in the morning. How many times can I dose before I lose pulsation? Six (6) a day every 3 hours
104
105How few times can I do it for some better sleep, small anti-aging effect? Just pre-bed.
106
107Step five: Assess tolerance by dosing just once w/ a GHRP pre-bed at half of saturation dose. Then if that goes well go to full saturation dose. If that goes well add a 2nd dosing, If that is fine add a third dosing.
108
109Step six: Decide on a dose. Saturation dose is defined as either 100mcg or 1mcg/kg of bodyweight in the studies. For the most part it is treated as 100mcg. That is the same for women and men. You will get added but diminishing benefit by dosing 200mcg, 300mcg perhaps 400mcg. A fuller explanation on why is available on the forum.
110
111What is Clinical Grade?
112
113American made in a lab that supplies people that do published research. The purity has to be high enough to allow ethical experiments in humans.
114
115What are all these peptides and what should I choose?
116
117First notice that I referred to GHRH, GH and Ghrelin as hormones. They are naturally occurring hormones whose structure is just one amino acid such Arginine bonded to another amino acid such as Lysine. They are both hormones and peptides. Sex hormones are examples of hormones that are not built in the body with amino acids.
118
119Now GHRPs do not naturally occur in the body but since they are mimickers of a hormone Ghrelin we can fudge and use the term hormone if we want. Growth Hormone Releasing Petites (GHRPs) as the name implies are built with attachments of amino acids.
120
121Which GHRH?
122
123The body makes GHRH which 44 aminos long. 15 amino acids are useless so the first 29 amino acids is what is known as GRF(1-29). Yes GHRH(1-29) makes more sense but someone chose G for "growth hormone", R for "releasing" and F for "factor". The numbers just tell you which amino acids from GHRH are kept.
124
125GRF(1-29) acts just like GHRH so I'll color it green. GRF(1-29) is an FDA-approved pharmaceutical drug named Sermorelin.
126
127So GHRH, GRF(1-29) and Sermorelin are basically the same. The problem though is they are easily eaten up by blood enzymes within minutes. If you could inject directly into the pituitary at the base of the brain then they will be effective, after-all that is what the brain drops into the pituitary. But circulating in the blood means they are rendered ineffective within minutes.
128
129That leaves us with analogs. An analog is a modification(s) to the peptide such that a property(ies) is(are) changed such as longer half-life, receptor binding affinity or receptor binding strength w/o losing the action. Many analogs can and have been made. However all you need is an analog that survives early blood plasma enzyme death and lasts say 30 minutes. Note a receptor is how some hormones/peptides interact with a cell. The hormone/peptide binds to a receptor on the outside of the cell and the message carried in. I purposely avoided receptor talk so as to avoid confusion and substituted the term "contact" and "contact with the cell".
130
131IGF-1 LR3 is an analog of IGF-1. It survives longer in plasma w/o binding to a binding protein but also has a lower binding affinity for its contact with the cell or better yet IGF-receptor.
132
133CJC is a term coined & used in a study that tested a newly created velcro type drug complex to attach to GRF(1-29) to allow it to cling to albumin in blood and give it protection and a long life (albumin has a very long plasma life).
134
135They tested three peptides/drug compounds. The first was simply GRF(1-29) with the drug affinity complex (DAC) attached. Think of that DAC as simply the velcro drug component. As you can see the CJCs are not pure peptides. They called this CJC-1288. It lasted about the same as plain old GRF(1-29). Blood plasma enzymes killed it in minutes.
136
137Then they took GRF(1-29) and made one amino acid swap plus the DAC (velcro drug) That means they took Arginine in the 2nd position of the peptide and replaced it with its mirror image form known as the D form. This makes the analog peptide stronger but not by enough. The half-life is maybe double GRF(1-29) in humans. So 5 minutes of half-life. This they called CJC-1293.
138
139Then they made 4 amino acid changes in GRF(1-29) to really strengthen it so it would last more then 30 minutes and added the drug affinity complex. This worked well for them because the peptide/drug hybrid lasted long enough to find the plasma albumin for the DAC part to velcro itself to for a long life of several days. This they called CJC-1295
140
141You want none of the CJC's. The first two because they do not survive long enough and the last one because it is always around. True somatostatin does pop up and stop GH release, but as soon as it can CJC-1295 is inducing GH release. The study itself found it increased base levels but did not increase pulses. That means there is less GH mass synthesized and stored in the somatotrophs. What are somatotrophs? Remember they are growth hormone releasing cells. The word may sound like somatostatin but only somatostatin has the power to stop GH release because? Because it is colored in red.
142
143Somatotrophs are not cells that release prolactin. Prolactin is released by Lactotrophs. Somatotrophs self organize into networks that coordinate GH release into a pulse. A fuller treatment is available on this forum.
144
145What do you want?
146
147You want the pure peptide part that was used in the third analog. You want those 4 modifications because they make what is essentially GHRH last for 30 minutes or more. This is a fine peptide to contribute to a GH pulse. This I call modified GRF(1-29). Since it is basically a 30 minute plus lasting GHRH I color it green.
148
149Which GHRP?
150
151GHRP-6 is sloppier in that it activates a wider array of effects beyond GH release. It causes intense hunger and gastic motility. It can have a mild effect on cortisol and prolactin. It is a first generation GHRP.
152
153GHRP-2 is less sloppy with a more intense GH release, no gastric motility and less hunger effect. It can have an effect within the normal range on prolcatin and cortisol. It is a second generation peptide.
154
155Ipamorelin is not sloppy at all. It does not release as much GH as GHRP-2 but it causes virtually no hunger or gastric motility and for the most part does not effect cortisol or prolactin. It is a third generation peptide
156
157You would choose GHRP-2 unless you wanted GHRP-6 for the hunger effect or for the lower release profiles.
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159You would choose GHRP-2 normally as the most bang for the buck.
160
161If you are very sensitive to perturbations in cortisol or prolactin you would choose the more expensive Ipamorelin.
162
163I Datrius B. True use either GHRP-2 or Ipamorelin with modified GRF(1-29) I usually rotate around.
164The History of Nutrition (supplements & Steroids) in Bodybuilding
165
166Splendid Specimens: The History of Nutrition in Bodybuilding By Randy Roach
167
168The sport called bodybuilding demands the ex-treme in body presentation. No other athletic endeavor requires such high levels of regimentation for muscle development and body fat reduction. To outsiders, such efforts may appear vain and self-centered, even looming out there on the lunatic fringe. Nevertheless, the sport has had considerable influence on other fields of athletics, not to mention the general public.
169
170We must remember that the men (and women) who sweat it out in the gym year after year were using the low-carbohydrate diet long before Dr. Atkins made it popular. Many other dietary strategies of today such as all-raw diets, protein supplementation, eating multiple small meals a day, carbohydrate loading, meal replacement packages and macro-nutrient balancing all derived their initial popularity from the bodybuilding field.
171
172PHYSICAL CULTURE
173
174Credit for the Physical Culture movement in North America, the precursor to the bodybuilding movement, goes to Bernarr Macfadden, an extraordinary entrepreneur who published physical culture magazines, organized physique competitions, wrote 150 books and accumulated millions in the publishing industry. Macfadden preached clean living and whole natural foods. He ate vast quantities of raw carrots, beet juice, fruits, dates, raisins, grains and nuts. He abstained from meat but recommended copious amounts of raw milk. In fact he even recommended an exclusive raw milk diet for extended periods.
175
176The dominant star of the early years was Eugen Sandow, whose career spanned the late 1890s and the early part of the 20th century. He did not display the typical burly brute image, but a finely chiseled body, resembling those of Roman and Greek athletes. With the help of Florenz Ziegfeld, he marketed and displayed his physique in artistic fashion. In fact, it was through this artistic expression that Sandow inspired Macfadden in the mid 1890s. In an 1894 interview on his dietary habits, Sandow claimed to abstain from hard liquor, coffee and tea, but consumed the occasional beer. He ate mostly wholesome foods, but indulged at selected opportunities. Sandow, along with most of the other Physical Culturists of his day, placed more emphasis on the mechanical aspects of diet as opposed to the chemical. He believed in doing what was necessary to facilitate good digestion, including eating at regular intervals, selecting simple foods, applying thorough mastication, eating slowly and tying it all together with a good night's sleep. He was critical of over-indulgence and recommended foods with a high nutrient value, although he admitted to eating what he wanted, when he wanted, and however much he wanted during his younger years.
177
178Earle Liederman, author and friend of Sandow, also advocated whole natural foods. Liederman pointed out the importance of a strong digestive system enhanced by proper food mastication for men of strength and large appetites. He described the popularity of "beef juice" or "beef extract" for rapid muscle recovery. Liederman also felt obliged to mention that ice cream was very popular, referring to one lifter who often felt it necessary to finish his meals with a quart of vanilla ice cream.
179
180Arthur Saxon of the famous Saxon brothers trio and a contemporary of Eugen Sandow, also recommended nutrient-dense foods for endurance athletes. He warned against the dangers of hard liquor, but condoned beer. In fact, Saxon had a reputation for hefty beer drinking as did many men of strength of the time. He warned against smoking while admitting to being a smoker himself. For gaining muscle, Saxon recommended milk mixed with raw egg after a workout, milk with oatmeal, cheese, beans, peas, and meat. He called milk the perfect food.
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182According to his brother Kurt, all three of the Saxon brothers had very hardy appetites. Along with his participation in the strength act, Kurt was also the trio's chef. Kurt's list of food consumed by the three brothers each day indicates substantial daily intake, with little self-denial. Milk is largely absent from Kurt's menus.
183
184RAW VERSUS COOKED
185
186A debate that has been on-going since the early days of Physical Culture is the relative virtues of raw food versus cooked. Sandow referred to the eating of raw eggs and under-cooked meats as nonsense and a practice that was "passing away."
187
188In the raw food corner was champion wrestler George Hackenschmidt, the "Russian Lion," a man rivaling Sandow's strength, and surpassing him in athletic ability. Like Sandow, he was small by today's standards, standing just under 5'10" and weighing about 200 pounds. However, he was enormously strong. Both a gentleman and sportsman, George Hackenschmidt reflected a spiritually conservative philosophy towards nutrition. In his book The Way to Life, he stated:
189
190"I believe I am right in asserting that our creator has provided food and nutriment for every being for its own advantage. Man is born without frying-pan or stewpot. The purest natural food for human beings would, therefore, be fresh, uncooked food and nuts." He stated that a diet of three quarters vegetable food and one quarter meat would appear to be most satisfactory for the people of central Europe but conceded a hardy appetite which, in his early training years, was based on 11 pints of milk per day, presumably raw, along with the rest of his diet. A prophet before his time, he warned about the dangers of refined sugar and meat from artificially fed and confined animals. He believed that most people ate too much flesh food from these improperly raised animals and encouraged more emphasis on natural raw foods.
191
192VEGETARIANISM
193
194The early bodybuilders also debated the pros and cons of vegetarianism. Macfadden and Hackenschmidt inclined towards diets that excluded meat, or that at least derived a preponderence of calories from plant foods. Juicing was popular among some. In his book Remembering Muscle Beach, Harold Zinkin describes fellow beach comrade Relna Brewer. At 17, Brewer worked in one of California's first health food stores, located in Santa Monica. Relna's job was to run the juice press. Because the owners of the store could not afford to pay much, Relna took out her pay in the celery, watermelon, orange and carrot juice she made each day.
195
196Jack Lalanne was probably one of Relna's customers. Jack began his carreer as a vegetarian, bringing his own food, such as apple or carrot juice and vegetables, to train at the beach during the 1930s. However, Lalanne later ate meat when focussed on bodybuilding. In fact, Armand Tanny says that Jack would visit the local stockyards to acquire cow's blood to drink while in training. Later Lalanne reverted back to his vegetarian ways, but allowing some fish and eggs.
197
198Lalanne opened one of the first health studios in Oakland in 1936. A colleague writes that Lalanne would work 14 hours a day then drive through the night 400 miles so he could be with the gang at Muscle Beach to participate in all the activities. When it came to pure energy and vitality, Lalanne was, and at 90 today, still is unbridled.
199
200Another vegetarian was Lionel Strongfort who promoted a system of raw foods based on fruits, vegetables, eggs and milk. He recommended very little meat and cooked fat. Strongfort suggested eating only two meals a day, a strategy shared by Macfadden that would re-emerge in the 60s and 70s. Strongfort and Macfadden both advised against overconsumption of food. They claimed overconsumption created a negative stress on the body's systems, sensible advice that bodybuilding publications would ignore in the coming years.
201
202Perhaps the most accepted food across all the early eating models for bodybuilders was milk. One of the most popular protocols for building size and strength was the combination of back squatting and drinking large quantities of milk. Joseph Curtis Hise was a pioneer of this system in the 1930s and after 70 years this strategy is still going strong in the drug-free world of bodybuilding.
203
204TONY SANSONE
205
206Another Physical Culturalist who advised against over-consumption was Tony Sansone, but Sansone understood the importance of flesh foods, including animal fats and organ meats. He wrote extensively on nutrition for bodybuilders and recommended nutrient-dense "foundation" foods such as milk, eggs, butter, meat, vegetables, fruits, and some whole grains, in that order. He also stressed the importance of organ meats such as liver, kidney, heart and cod liver oil and recognized the need to drink whole raw milk instead of pasteurized and skimmed. He believed goats milk was more nutritious and easily digested than cows milk. Fresh butter and cream were his preferred fats. He also recommended six to eight glasses of water per day.
207
208Tony Sansone wisely stressed the importance of generous amounts of fat in the diet to allow the complete utilization of nitrogenous (protein) foods in building muscle tissue--a fundamental and important fact that would be lost as the era of protein supplements took hold. He also knew that weight loss was not a matter of simple calorie counting, as cellular uptake or utilization of food varied on an individual basis. In anticipation of Dr. Atkins, Sansone recommended his foundation foods of milk, eggs, meat, vegetables and fruit for strength and health, and starchy foods as weight manipulators. His recipe for gaining weight was to add more high-carbohydrate foods such as bread and potatoes to the diet, and for losing weight to simply reduce or remove them. Tony Sansone's caveat to lose no more than two pounds of fat per week is still the standard used in bodybuilding today.
209
210MUSCLE BEACH
211
212Muscle Beach got its start in the 1930s as the meeting place of young athletes who lifted weights, built human pyramids, tumbled, juggled and engaged in any other athletic endeavor they could think of. That era gave us many recognizable names such as Harold Zinkin (creator of the Universal weight machine), Joe Gold (creator of Golds Gym), Jack Lalanne, Harry Smith, and the Tanny brothers, Armand and Vic (who created a popular gymnasium chain). In fact, it is safe to say that much of the fitness industry grew out of Muscle Beach--gyms, gym chains, TV exercise programs, fitness equipment, women lifting weights, even aspects of the natural organic food movement stemmed from this small stretch of sand.
213
214According to Harry Smith, long-time gym owner, ex-pro wrestler and Muscle Beach alumnus, body builders didn't think much about specialty food or supplements in those days. The emphasis was on training rather than eating and resting. Harry did state that many of them tried to keep their eating clean, and that on a number of occasions they would frequent a small deli about one-half block from the beach. The deli offered freshly ground beef to which some of the guys would mix some raw onions and a little salt and pepper. The meat was eaten raw along with raw milk. Harry said it was a cheap and easy way to eat hardy and keep out of the restaurants.
215
216One important Muscle Beach raw food enthusiast was Armand Tanny. Originally a weightlifter, Armand had a fantastic physique and the strength to qualify him for the wrestling circuit. He visited the Hawaiian Islands just after the Second World War and came away with a lasting impression of the Samoans. "They ate everything raw," he noted. "You name it, fish, meat, beetles--everything! They were so strong and healthy." On his return to the US, he became interested in the work of Weston A. Price, stating that Price's book Nutrition And Physical Degeneration served as his Bible.
217
218In 1948 he shut off his stove and ate just about everything raw from then on--tuna, beef, liver, lobster, oysters, clams, nuts, seeds, fruits and vegetables. Armand recalls wading out into the surf along the Santa Monica Pier and using his feet to kick up 6- to 7-inch Pismo clams, smashing them together to get at the pink and white flesh. Armand also took brewer's yeast, desiccated liver, yogurt, black strap molasses and wheat germ oil, all recommendations of Gaylord Hauser, a nutritional guru of the era. Hauser also recommended fish liver oil, but Tanny felt he was getting plenty from all the raw fish he was consuming.
219
220Armand credited his 1950 Mr. USA and the Pro Mr. America titles to his raw meat diet. In the 1950s, he helped his brother Vic in the gym business and appeared in a Mae West act. His bodybuilding articles appeared prominently in bodybuilding publications for the remainder of the century, thus providing a link to Weston Price during the decade of the 50s.
221
222BULKING UP WITH JOHN GRIMEK
223
224The biggest influence on bodybuilding in the 1930s and 1940s was John Grimek, the second American Athletics Union (AAU) Mr. America and the first to win back-to-back titles, in 1940 and 1941. Many commentators believe that Grimek represents the beginning of modern bodybuilding as we know it today, describing him as the best physique of the mid century.
225
226During the early 1930s, at the start of his career, Grimek came under the influence of Mark Berry, editor of Strength magazine and an advocate of an eating protocol in which an athlete would bulk up in bodyweight and then train it off. At one point, Berry had Grimek beef up his 5' 8" frame to 250 pounds. The practice would become commonplace by the 1950s and maintain a foothold for several decades after.
227
228Grimek bulked up on whatever was put in front of him, reports his wife Angela in a 1956 Health and Strength article entitled "Life with John." "John has an enormous appetite. . . John has yet to find a restaurant that can do justice to his appetite. . . . Sometimes he goes on a restricted diet--and it is surprising how little he can get by on then. But when he goes all out, he can never be filled. . . . but the ‘hog' (our pet name for John) just eats and eats and still remains trim and muscular."
229
230By the 1950s, Grimek's diet included Hershey chocolate bars and hi-protein tablets manufactured and promoted by Bob Hoffman, publisher of Strength and Health, a magazine that provided a platform for Grimek along with the new-fangled supplements coming on the market. Hoffman used Hershey chocolate in his products, so Grimek and the rest of the York gang had easy access to some empty calories.
231
232PROTEIN POWDERS AND SUPPLEMENTS
233
234In the late 1930s a young pharmacist named Eugene Schiff developed a method of processing whey from milk for human consumption. He created Schiff Bio-Foods, a whey packaging company. This was a half century before whey concentrates would emerge as a popular supplement in the bodybuilding scene. For a short time he sold his packaged whey to local drug stores, then sold his own store to enter into the manufacturing and packaging of health foods.
235
236Schiff focused on supplements made from natural products. He began to experiment with whole foods such as brewer's yeast, wheat germ and liver. He found that these foods were naturally rich in vitamins and minerals. The Schiff company claims that he was first to discover that rose hips was a superior source of vitamin C. Along with the first rose hip vitamin C supplement, he also launched one of the first multi-vitamin products, called "V-Complete."
237
238The demand during World War II for non-perishable foods allowed the food industry to expand and popularize the market for powdered or dehydrated foods and bodybuilders would eventually find their way into this market. Powdered milk and eggs, and later powdered soy protein, were promoted as an easy way to get additional protein into the diet. Breakfast drinks based on a protein powder emerged into the diet of the legendary Steve Reeves who years later wrote about this practice in his book Building The Classic Physique. Reeves' impressive natural physique landed him starring roles in the films Hercules and Hercules Unchained in the late 1950s and inspired thousands of young men to adopt weight training. His recipe for a breakfast drink included fresh orange juice, Knox gelatin, honey, banana, raw eggs and a blend of skim milk, egg white and soy protein.
239
240The first protein powders "tailored" specifically for athletes appeared around 1950. One of these was called 44, "The Supplemental Food Beverage," produced in California by a company called Kevo Products. The principle ingredient was dehydrated powdered whole soy beans, along with kelp, wheat germ, dextrose, and various dehydrated plants, herbs and flavorings. The supplement was sold at health food stores, body-building studios, and health institutes.
241
242Another popular product was Hi-Protein, "a protein food supplement derived from soya flour, milk proteins, and wheat. The free amino acids which include natural tryptophan and the other natural essential amino acids where produced by an acid hydrolysis." The product was developed by bodybuilder and nutrition guru Irvin Johnson with before and after photographs of weaklings turned musclemen. Bob Hoffman quickly capitalized on Johnson's success by following immediately with his own soy-based product marketed heavily in Strength and Health. Hoffman's infamous protein claimed many a victim with hives or gym-clearing gas.
243
244The debates on raw versus cooked and vegetarianism versus meat eating that appeared in bodybuilding magazines during the 1940s gave way to numerous articles on protein supplements in the 1950s, including "Building Biceps Faster With Food Supplements (Iron Man, December 1950," "More and Better Protein Will Keep you Well (Strength & Health, March 1953)," "The Magical Power Of Protein (Mr. America, February 1958)," "Food Supplements Build Rock Hard Definition (Muscle Builder, June 1958)" and "Everyone Needs More Protein (Strength & Health, July 1959).
245
246Meal replacement products also appeared during the 1950s, with much hype. One product, called B-FIT, was recommended as a replacement for two or three regular meals per day. According to its promoters, B-FIT "is scientifically formulated to contain all the needed vitamins and minerals, plus ample supplies of the effective proteins and yet is so low in calories that the fatty tissue literally melts away. . . . You will not suffer from any nutritional deficiencies because B-FIT is a complete food insofar as scientific experiment and research is possible to develop. Approved by dieticians."
247
248Advocates for new diet theories--food combining, alkaline-forming diets, even strict vegetarianism--promoted their ideas throughout the 1950s, but the big emphasis was on protein powders and supplements. For the 1954 world weightlifting championships, team coach Bob Hoffman hauled more than 100 pounds of his Hi Protein powder to Vienna, hailing it as the "secret weapon" for his athletes. But Russia, whose athletes finished no lower than second place, had a secret weapon of their own.
249
250THE SECRET WEAPON
251
252It was John Ziegler, a doctor accompanying the American team to Vienna, who exposed just what this Soviet weapon was. Ziegler claimed that after a few drinks, a Russian doctor told him that the Soviet athletes were using--and abusing--testosterone. Ziegler was no stranger to testosterone. With his background in rehabilitation therapy and his connection with CIBA Pharmaceuticals, he was already experimenting with testosterone on himself, his patients and some novice athletes. In fact, author and historian John Fair writes that even the great John Grimek was cooperating with Ziegler and trying his drugs in the summer of 1954. Grimek reported disappointing results.
253
254Both American and German research scientists had identified testosterone and noted its effects as far back as the mid 1930s. CIBA Pharmaceuticals was already targeting bodybuilders with ads for synthetic testosterone in 1947. With Ziegler's help, CIBA manufactured the most popular anabolic steroid of the 20th century. The drug was Dianabol, which came out in 1958.
255
256The acceptance of steroid drugs among bodybuilders got off to a slow start. Drinking a gallon of milk or swallowing 2000 protein pills seemed more logical to them than taking a tiny pill to do the job. Even those who did take them were slow in accepting or acknowledging the fact that it was the steroids that were giving them such tremendous gains in muscle mass.
257
258Out on the West Coast, bodybuilding great Bill Pearl was also curious as to what the Russians were doing, so he took it upon himself to do his own research. During a visit to the University of California at Davis in 1958, he learned from a veterinarian about the successful use of steroids in beefing up cattle. Bill figured that if it was good enough for a bull, then it was good enough for him. While continuing to train hard, he took 30 mg of the steroid drug Nilevar (three times the recommended dose for humans, but an absolute joke by today's practices) for 12 weeks and brought his bodyweight up from 225 to 250 pounds.
259
260Steroid use among athletes paralleled the challenge to conservative moral standards that characterized the era of the 1960s. It was a time that seemed ripe for the liberation of one's desires. Individual freedoms took precedence over the rules, morals and ethics dictated by a long established culture--and by Mother Nature. If the new generation could take mind-altering drugs, it could take body-altering drugs as well. Anabolic ("building-up") steroids such as testosterone ushered in a new bodybuilding look that was larger and more muscularly pronounced than ever before.
261
262During the early 1960s, the magazines emphasized caution about steroids. They acknowledged the rumors concerning Bill Pearl and others but tried to steer their readers away by stating that the drugs didn't work, wouldn't produce what bodybuilders expected, or were outright dangerous. Both Iron Man and Muscle Builder magazines warned of side effects and published articles claiming much better results with high-protein products. But behind the scenes, the athletes knew that they worked. Pearl openly acknowledged that he used them for a final time in 1961 to prepare for the 1961 National Amateur Bodybuilding Association (NABBA) Mr. Universe contest. He stated that the drugs by then were no longer underground but well known to the top bodybuilders.
263
264STEROIDS AND CREAM
265
266Still, most athletes relied on diet for strength-building, and protein occupied a large percentage of that diet. In the early 1960s, Irving Johnson targeted elite bodybuilders with a milk-and-egg protein blend considered far superior to competing products--including an earlier product of his own--based on soy. By the mid 60s, ads for Johnson's protein blend began appearing in the bodybuilding magazines. At that time he changed his name to Rheo H. Blair. Blair claimed that his protein powder was made from milk and eggs obtained from animals raised on the rich soil of Wisconsin and that the proteins were extracted at very low temperatures. Wary of the difficulty some might have digesting all that protein, he endorsed hydrochloric acid supplements, to be taken with any protein meal. He also sold supplements such as amino acids, liver extract, B-complex and soybro (a combination of wheat germ, rice germ and soy germ oils). In 1966 he introduced a new protein formula which he claimed had a biological value resembling mother's milk.
267
268Blair promoted his products with skillful salesmanship but he also made an important suggestion that would ensure that his products actually worked--he insisted that his protein be taken with raw cream or half and half. He was smart enough to know that you must replace the fat removed from protein during processing. He also recognized the benefits of raw dairy products. Athletes of the 1960s used a variety of recipes, varying the proportions of Blair's protein product with raw cream, raw milk and raw egg yolk. Weight-trainer Don Howorth remembers eating 3 dozen eggs, 1 quart raw cream, and 2 pounds ground sirloin along with 2-3 cups of Blair's protein powder per day.
269
270Blair had a special method for cooking his eggs. He did not cook them in boiling water but recommended cooking many eggs at one time in water maintained at 181 degrees for 31 minutes. The eggs were then left in the water to cool down slowly. Blair claimed that putting the eggs under cold water "shocked" many of the nutrients, rendering them ineffective and that cooking eggs in this fashion preserved much of their nutritional value.
271
272It is interesting to read Perry Rader's "Reader Roundup" column in his Iron Man magazine during this time. He tries to explain the spectacular gains made by some of thepopular bodybuilders who were using Blair's products. Many of them were eating 6000 to 9000 calories a day in the same fashion as Don Howorth and gaining muscle while maintaining or even trimming their waist size. Rader published Blair's response in a 1966 issue of Iron Man. Blair claimed that his protein powders, along with all of his other supplements, were formulated in a special manner to metabolize fat more efficiently. He also warned that taking cream with any protein powder other than his own would result in fat accumulation.
273
274But Blair could not help knowing that these dramatic results were not achieved on food and protein powders alone. Bodybuilders knew that they could expect to build muscle consuming 8000 calories per day, but not lose fat at the same time. That required some additional anabolic assistance. Blair knew his guys were taking steroids. Don Howorth readily admitted his past use of Dianabol, but was adamant about the importance of diet along with it. In fact, some bodybuilders were quite open about drugs. When Larry Scott, two-time winner of Mr. Olympia, was asked about his steroid use he said without hesitation, "Sure, doesn't everyone?" However, the bodybuilding magazines continued the deception that the new, larger physiques were built on powders and supplements. Thus steroid use artificially inflated the already marketable commodities of bodybuilding.
275
276VINCE GIRONDA
277
278One man who had definition dieting mastered and who never used drugs was the Iron Guru Vince Gironda. Pioneer of a technique involving intense abbreviated training routines rather than long workouts, Gironda began competing in the 1950s and then trained both athletes and movie stars for many decades after. So defined was his physique, he often found himself penalized by judges who seemed confused over his appearance. Says Gironda, "The men who judged physique contests at this time were puzzled by so much muscularity. Quotes from physique magazines stated I didn't place higher in whatever contest because of too much muscularity. They thought that this type of cut-up physique was slightly repugnant so I lost most muscular titles to smoother men who had that type of definition for that day."
279
280Gironda often stated that nutrition was 85-90 percent of bodybuilding. His alternative to drugs was eggs. Like Blair, he advocated up to 36 eggs a day for 6 to 8 weeks to produce muscle buildup. (He also took, among many other supplements, "orchic tissue tablets," that is, dried testicles.)
281
282He recommended following this "anabolic phase" with a short-term vegetarian diet to "re-alkalize" the body. Similarly he alternated a low-carbohydrate diet with periods of carbohydrate loading. He was careful to point out the difference between natural and refined carbohydrate foods. He presented research data that strongly indicted refined carbohydrates as the real culprit in much of the century's degenerative disease. His articles went into surprising detail on the biochemical pathways through which sugar did its damage, pointing out the relation between sugar and atherosclerosis, abnormal increases in height and weight and skeletal anomalies.
283
284As for protein, he believed the average American could get along fine with just 45 grams of quality protein a day. However, he insisted that bodybuilders needed over 300 grams daily for several weeks to force the growth process. He believed in quality protein powders and used Blair's milk-and-egg blend until he came out with his own product. When he used the powders, he blended 1/3 of a cup with a dozen eggs and 12 ounces of raw cream or half & half. He was also big on steak and often ate his meat raw.mmended germ oils, amino acids, vitamin and mineral supplements, and hydrochloric acid (HCL). He recommended mineral rich sea kelp for its iodine content and dried liver extract for blood building and oxygen capacity boosting. Many bodybuilders used desiccated liver after the early 1950s experiments of Dr. Benjamin Ershoff. Ershoff who conducted the famous liver study wherein rats fed 10 percent desiccated liver swam far longer compared to controls.
285
286MACRONUTRIENTLAND
287
288In his early years, Blair recommended a very low carbohydrate diet. Later he advocated a diet consisting of 1/3 protein, 1/3 fat and 1/3 carbohydrates to build muscle; then he reversed himself and again urged avoidance of carbohydrate foods. But other bodybuilders included high levels of carbs in their diets. For example, teenage sensation Casey Viator, who became the youngest Mr. America ever at age 19, had his own special peanut butter pudding that consisted of 2 pounds of peanut butter, 1 jar of grape jelly and 3 or 4 bananas. The bananas were optional. This was part of a diet that also included 2 dozen eggs and 2 gallons of raw milk per day. Casey recalls his father not shedding too many tears when he finally moved out.
289
290A columnist in Strength & Health magazine recommended the following carbohydrate-rich concoction for "getting big" along with a diet that allowed unlimited meat and eggs:
291
292A one day supply of Hoffman's Gain Weight formula (based on soy protein) 2 quarts milk 2 cups skim milk powder 2 raw eggs 4 tablespoons peanut butter ½ brick ice cream 1 banana 4 tablespoons malted milk powder 6 tablespoons corn syrup
293
294By the 1960s, bodybuilders had figured out what they had to do to attain specific goals. Getting lean or "ripped" for a contest required stripping the diet of all carbohydrates, including milk and cream. Milk was a favorite for building muscle, but for losing fat, it contained too much carbohydrate and held water under the skin. Ketogenic diets consisting of meat and water were commonly used to prepare for the shows. During the 1950s, two English researchers--Professor Kekwick and Dr. Pawan--claimed to have isolated a fat-mobilizing substance that showed up in the urine along with ketone bodies after 24 hours on a no-carb diet. In spite of considerable scientific debate, the Ketogenic diet remained a constant in the field of bodybuilding until the 1980s.
295
296Yet it was in the early 70s that the lipid hypothesis began to take hold. The result was a series of diets that emphasized carbohydrates over protein and fats. The pre-game meal of beef was giving way to one of lasagna or spaghetti.
297
298The magazines of 1970 mirrored this confusion. For example, in an issue of Strength & Health, publisher Hoffman praises the African Masai tribe for their reverence of whole milk, while in his other publication, Muscular Development, he recommends skim milk because it is lower in saturated fats. (The vast majority of the nation was now drinking pasteurized milk--long time strength trainer Jim Bryan remembers avoiding raw milk because he was given the impression that it was dangerous.) MuscleMag publisher Bob Kennedy told his readers not to let anyone scare them away from eggs. Frank Zane, Mr. Olympia champion from 1977-79, was still eating the old way with plenty of eggs, lamb, beef, pork, heart, liver, raw milk, protein powder, vegetables, fruit with some potato and brown rice, educating his readers on the misconception of cholesterol and warning against over-consumption of polyunsaturated vegetable oils. But in Iron Man, Sterri Larson was telling readers that the diet of the bodybuilder was not necessarily one to produce good health. He believed that eggs were the best for both building muscle and losing fat, but that saturated fat and cholesterol could prove hazardous. According to bodybuilder Brian Horton, some of the athletes were now eating chicken and fish instead of beef and eggs.
299
300STEROID USE
301
302Meanwhile, by the end of the 1970s, professional bodybuilders were using a number of metabolism-enhancing substances such as amphetamines, Armour (Thyroid), human and animal growth hormone, and multiple steroids (a method referred to as "stacking"). Some of the top pros worked with physicians to monitor their blood parameters as they prepared for their competitions. During the months before an event, these athletes would swallow and inject any substance that would facilitate tremendous muscularity. Very few, if any, bodybuilders could attain such condition without this assistance.
303
304Steroid use suffered a setback with the revelation that 1988 Olympic gold medal sprinter Ben Johnson had tested positive for anabolic steroids, which had been banned from use in the Olympic games since 1975. In 1990, the Food and Drug Administration added steroids to the Schedule III list of the Controlled Substance Act. Since then, any athlete seeking to build muscle via anabolic steroids could just as easily find his next workout conducted in a Federal prison gym -- and several have, to the dismay of many in the legal, medical and sports arenas.
305
306The ban on steroid use was no surprise to the bodybuilding world since abuse of the drugs, even at the high school level, was well known. Not only was the number of users growing, but so were the dosages and arsenals in professions where size and strength really made the difference.
307
308The magazines were not yet labeling heart disease as a side effect of steroid use. However, by 1970 they were starting to mention the fact that a number of strength athletes were succumbing at their prime. Columnist Bob Brown described his concern over losing friends at an early age to heart disease and wrote an article in Iron Man entitled "Will Weight Training Kill You?" Brown compiled some death statistics on prominent men of the iron game throughout the century and compared them to some mortality stats supplied from an insurance company. He concluded that even though strength trainers were not immune to early death, they fared better than the average American and stood a much better chance at living a longer life.
309
310Others noted the shortened careers of top bodybuilders. The 1967 Mr. America Don Howorth considered a comeback, but stated he knew his body would not do well with what he had to take at that stage of his life. Even the genetically blessed Casey Viator who was a serious contender for the Mr. Olympia title, walked from any more attempts in 1983 knowing that his body had had enough.
311
312NEW DIETARY TRENDS
313
314In the early 1980s, bodybuilders became interested in the glycemic index of carbohydrate foods. A team of researchers at the University of Toronto, led by Dr. David Jenkins, demonstrated that different foods affected blood glucose levels at different rates. They developed the Glycemic Index in which many carbohydrate foods were measured against selected reference foods on how quickly they raised glucose levels.
315
316Many bodybuilders and other athletes used the glycemic index to plan their daily menu and carbohydrate selection. With the insurgence of carbs into the diet, along with a well-established reverence for protein, bodybuilders discovered there wasn't much room left for fat. In fact, by the end of the decade, many found themselves in a competition for who could get their dietary fat the lowest. Some even attempted a theoretical zero fat diet.
317
318But not everyone was taken in. I interviewed bodybuilder Ron Kosloff who said he didn't change a thing. "I knew what I saw," he told me. "My grandparents lived on a farm and ate whole milk, cream, eggs, butter, meat, potatoes and homemade bread. My grandfather often ate 6 eggs a day for years, many of them raw, along with lard sandwiches. He lived to 98 while my grandmother lived to 101. What astounded me most was their farmhand who went by the name of Indian Joe. When I first saw him he looked in his 40s and was incredibly cut and muscular. He looked like Conan. I was shocked when I found out he was well into his 70s. Indian Joe lived to 115 years of age and ate nothing but meat, glands and intestines!" Kosloff had consumed a minimum of 6 eggs daily for the previous 20 years with no ill effects. Ron also noted that bodybuilders like Gironda and Blair were warning him back in the late 60s of the real hazardous fats--hydrogenated oils!
319
320Armand Tanny, now in his 60s, was also writing articles contradicting this new trend. All through the 1980s he wrote articles for Joe Weider's Muscle and Fitness magazine such as: Caveman Diet (March 1986), Meat and the Bodybuilder (Dec 1986), Good Nutrition and Sex (June 1987), Streamline Meat (Oct 1987), Uncooked Delicacies (Dec 1986), and Those Beefs About Meat (Oct 1985).
321
322In the midst of the cholesterol scare in 1984, Vince Gironda released his book Unleashing The Wild Physique, still recommending 36 eggs a day to produce an anabolic effect. However, he also wrote an article defending carbohydrates and warning of the potential risks of high protein consumption.
323
324PUTTING THOSE CARBS TO WORK
325
326A major trend in the 80s and 90s was the concept of carbohydrate loading, first popularized by Vince Gironda back in the 50s and 60s. "I believe that every 3 to 5 days you need to get a ‘carbohydrate loading meal' into your body
327
328. . . I feel that carbohydrate is necessary every third or fifth day in order to get the glycogen back into the liver."
329
330Also back in the 1960s, cyclists were using a technique of loading their muscles with carbohydrates to give themselves an endurance edge. Bodybuilders were also loading their muscles just before a competition to give them a fuller look. Into the 1980s, the competitive bodybuilders had brought it into a science with their knowledge of the hormones vasopressin and aldosterone and how they controlled the sodium/water balance in the body. The challenge was to stand on stage on competition day with as much body fluid sucked into the muscles with the carbohydrates and not under the skin. The effect of this technique was so dramatic that hit or missed timing could represent a victory or looking terrible for bodybuilding standards. Often bodybuilders would be banging their heads off the wall one to three days after a big show when all the fluids would shift into the right places--too late!
331
332Similar diets followed including Cyclical Ketogenic Dieting (CKD) variously known as the "Ultimate Diet," the "High-Fat Diet," the "Anabolic Diet," "Bodyopus," the "Metabolic Diet," "Anabolic Solution," and the "Ultimate Diet 2.0."
333Estrogen - Women & GHRH/GHRP-6
334
335ESTROGEN
336
337Well DHEA conversion to estrogen has a pronounced positive effect on GH.
338
339But I wonder...if you have a big fat pad & are an older guy or even a younger guy with a hormonal profile skewed toward "excess" estrogen already...whether DHEA will have a positive impact on GH production.
340
341Conversely what happens when we reduce either estrogen or its ability to act...
342
343AND which is more important in regard to negative impact on GH:
344
345    the act of aromatization of testosterone to estradiol or
346    absolute estrogen levels
347
348Well that study I posted in post #492 found that the aromatization of testosterone to estradiol was important and that tamoxifen at 20 mg/day for 3 weeks reduced GH by about 50%, GH pulse by about 40% and IGF-1 by about 30%.
349
350How about estrogen in general? ...lets look at estrogen supplementation (in females)
351
352Well estrogen impairs the action of GH. Women are less responsive than men to GH treatment.
353
354Oral estrogen especially inhibits GH's actions in dose-dependent fashion. However transdermal estrogen administration seems to bypass some of the increases in body fat and reductions in lean mass often seen in postmenopausal women given oral estrogen....so that mode of administration appears to minimize some of the negative impact of GH.
355
356Oral estrogen administration leads to a reduction in IGF-I levels despite any increase in GH levels (from supplementation). The reason being that estrogen impairs the ability of GH to stimulate hepatic IGF-I production because of its negative impact on the growth hormone receptor and signalling.
357
358Estrogen inhibits GH activation of the JAK/STAT pathway. The inhibition is dose-dependent and results from suppression of GH-induced JAK2 phosphorylation, leading to reduction in transcriptional activity. Estrogen does not affect phosphatase activity but stimulates expression of SOCS-2, which in turn inhibits JAK2 activation. Thus, esotrogen inhibits GH receptor signalling by stimulating SOCS-2 expression. - Growth hormone receptor modulators, Vita Birzniece & Akira Sata & Ken KY Ho, Rev Endocr Metab Disord So how does estrogen effect the use of GHRH and GHRP-6 to effect release of GH?
359
360It seems that GHRP-6 (assume all GHRPs) induce a greater GH release response in the somatotrophs in the presence of estrogen then GHRH. Estrogen administration markedly decreases GH release in response to GHRH. *
361
362So women should always include a GHRP (GHRP-6, GHRP-2, Hexarelin, Ipamorelin) in their therapy. GHRH (mod GRF(1-29), Sermorelin, CJC-1295) by itself will be inhibited in its action on GH release by the sex hormone estrogen.
363
364    - Regulation of His-dTrp-Ala-Trp-dPhe-Lys-NH2 (GHRP-6)-lnduced GH Secretion in the Rat,Federico Malloa, Neuroendocrinology 1993;57:247-256
365
366THE EFFECTS GH AND INSULIN
367
368"I hate people that are gurus because they usually don't know what the hell they are talking about. What I've always tried to do is point to the science and let people "understand" things on there own.
369
370My thread at PM contains a lot of knowledge about many things beyond just peptides including insulin.
371
372So lets start first with the myth that GH & Insulin can not be used together. Do people even understand that the GH ligand is only half of the equation? GH needs a receptor to bind to. Do they know how to increase GH-receptors? How about increasing GH receptor expression.
373
374Since I just now decided to toot my own horn ...toot toot... let me also say the same applies to testosterone. There is a simple way to increase androgen receptors expression. No I'm not going into that... I just marvel at the guys who are gurus that don't understand these simple things...
375
376First a response from Dr. Crisler who addressed this doctor myth about separating insulin & GH. He was responding to my post on how insulin effects GH-receptor expression.
377
378Here is Dr. Crisler's response to my post which I will summarize afterwords:
379
380    So much for the Anti-Aging Medicine doctors out there who tell their patients who take GH in the morning to not eat until a couple hours after their shot.
381
382Their reasoning (if you call it that LOL) is insulin blocks the IGF-1 receptor, even though the affinity for same is 2 to 3 orders of magnitude less (at appropriate serum concentrations) than it is for IGF-1.
383
384Applying Farmer's Logic, how long would it be then since you last ate?
385
386You need SOME insulin (but not too much), like it is for estrogen
387
388The point is that doctors that perpetuate the "don't eat or increase insulin with GH" are wrong.
389
390Dr. Crisler was responding to my post which discussed a study which focused on the need for insulin to increase GH-receptors. In other words insulin increases GH-receptor synthesis. However at some point the amount of insulin that is administered begins to have a negative consequence. This negative consequence is that higher amounts of insulin will start to inhibit the birth of those newly created GH-receptors.
391
392So to summarize insulin increases the synthesis of GH-receptors which will be available to bind to the GH ligands. This is good. At some point though high levels of insulin will stop those newly created receptors from making their way to the cell surface. This is bad.
393
394So I undertook to calculate the point where insulin would shift from being a positive to a negative. My conclusion:
395
396    Therefore the point at which the amount of insulin in plasma becomes a negative rather then a positive is approximately 7.5 to 9 IUs.
397
398So to arrive at a net benefit an insulin amount below that threshold point such as 5-6 ius is desirable.
399
400All of this is only focusing on insulin's effect on increasing GH-receptors. Which is positive to a point and negative beyond that point.
401
402In addition Dr. Crisler underscores the point that insulin at moderate dose will not interfere with IGF-1 binding to a receptor.
403
404What we didn't discuss was that IGF-1 is not synthesized straight away all at once by GH. Rather GH sets in motion a chain of events that results in IGF-1 synthesis over a long period of time. Not minutes...but rather hours even a day+. That is one reason why IGF-1 levels build up every day that you take GH until they plateau about a week out.
405
406So tell me how insulin use concurrent w/ GH can effect eventually binding of newly created IGF-1 to its receptor.
407
408If you follow that reasoning you should NEVER take insulin. The truth is you can take it together w/ GH or 30 minutes later or in between GH pulses.
409
410Okay this is one thing that insulin does but there so many more things to that insulin does. Do people even know what GH does by itself, what insulin does by itself, what all sorts of things do by themselves. How about if you combine them?
411
412I would copy my posts on this from PM but the formating is lost so I'll just post the links (it is formatted by me to be highly readable & well worth the time to read by anyone who wants to truly understand):
413
414The above post covers:
415
416    Insulin
417    Growth Hormone
418    Amino Acid Pool
419    Exercise
420    Blood Flow
421    IGF-1
422    IGF-1/IGFBP-3
423    Androgens
424    Thyroid Hormones"
425
426THE SCIENCE BEHIND: ‘SYNTHETINE – LIPID (FAT) TRANSPORTER’
427
428Synthetine™ is an L-Carnitine based sterile preparation manufactured by a pharmaceutical company in accordance with the highest level of manufacturing practices. Synthetine is a highly bioavailable form of L-Carnitine that if used together with SyntheDextrin will activate a “switch” that will reduce carbohydrate oxidation and increases fat oxidation in contracting muscle, reduce fatigue, reduce muscle glycolysis and increase glycogen storage during periods that are almost always reserved for carbohydrate oxidation..
429
430The science presented in this article is unique. It details a proven but little known protocol using Synthetine™ and SyntheDEXTRIN™ that immediately enables the regulation of muscle fuel selection in favor of utilizing fats.
431
432The focus of this article is an attempt to describe the science with enough detail so that the readers can incorporate this knowledge into their own plans to advance their fitness and health goals. This article is not about selling the aforementioned products. In the studies a highly bioavailable sterile L-Carnitine such as S ynthetineâ„¢ was used repeatedly together with either insulin or high glycemic shake such as SyntheDEXTRIN™ in the protocol that immediately activated the switch. However a second protocol is fully described herein and it involves low bioavailable oral ingestion of L-Carnitine and high glycemic shake. This second method is a slow build up process requiring daily use for 100 days to be fully active.
433
434I make no apologies for the length of this article. I have kept the science understandable by introducing key concepts before explaining their specific relevance to the focus of this article. I have included a table of contents to make navigation easier.
435
436During the 1990’s a substantial amount of research was undertaken which investigated the effects of L-carnitine supplementation on exercise performance. The primary hope of the research was that increasing carnitine availability in the body would lead to increased fat oxidation during prolonged exercise, spare glycogen stores and, consequently delay the onset of fatigue as well as promote fat loss. Scientific interest in L-carnitine as a performance enhancement and weight loss tool came to an end when it became apparent that L-carnitine feeding does not alter fuel metabolism during exercise or, more importantly impact upon the muscle carnitine pool in humans.
437
438The scientific community for the most part abandoned further research. L-carnitine’s metabolic role had been thoroughly mapped out and described in the literature. The typical carnivorous diet seemed to supply sufficient carnitine. Carnitine supplementation proved to be of no additional benefit…it was simply excreted… end of story.
439
440Despite the failure of science, L-carnitine feeding as a tool to promote weight loss and improve exercise performance became a multimillion dollar dietary supplement industry with no genuine benefit to the end users.
441
442Today our understanding of the transport mechanisms that permit cellular membrane penetration are much more advanced. What was once a saturated transporter and an impermeable membrane are now elements that are open to favorable manipulation, sometimes in surprisingly simple and physiologically obtainable ways. The hopes and hypes of yesterday with the scientific approaches described herein are reborn anew.
443
444Synopsis
445
446This article summarizes in understandable language the elements of metabolism that are necessary to appreciate both the mechanisms and conclusions arrived at through a series of studies published in very well respected journals by a group of scientists I’ll label the “Stephens Group”. The group of four scientists, headquartered at the “Centre for Integrated Systems Biology and Medicine” at Queen’s Medical Centre, University of Nottingham in the United Kingdom examined carnitine’s importance as a regulator of skeletal muscle fuel selection.
447
448They came to the understanding that because carnitine is vitally involved in both fat metabolism and carbohydrate metabolism in the cellular mitochondria (where energy production takes place) and because the pool of available carnitine is restricted at that level, carnitine availability is “the switch” that toggles between these two systems for energy creation.
449
450There are periods of times when the use of glucose (derive from carbohydrates) as a fuel increases. This occurs at high intensity exercise and when there is plenty of glucose available. When this occurs this metabolic pathway calls upon carnitine within the mitochondria for use in the process and this takes away from the carnitine that is available for fat metabolism. This results in a “switch away” from the use of fats for fuel in favor of glucose.
451
452The Stephens Group was able to fully describe this process and discover that there exists a “switch back” which reduces glucose metabolism and increases fat metabolism even during those periods of time (high intensity exercise, carbohydrate intake and preference for glycolysis) that normally demand otherwise.
453
454In essence they discovered that increasing skeletal muscle carnitine above a threshold inhibited carbohydrate oxidation.
455
456They then moved forward and also discovered that increasing skeletal muscle carnitine above a threshold also increased fat oxidation.
457
458Having identified this “switching mechanism” they then discovered that increasing muscle carnitine content in healthy humans at rest reduced glycolysis, increased glycogen storage and increased fat oxidation.
459
460They then came to the understanding that increasing muscle carnitine content alleviated the decline in fat oxidation rates during high intensity exercise and reduced muscle glycogen utilization. They were able to reference in vitro (out of body) studies that reported that increasing muscle carnitine substantially delayed the onset of fatigue.
461
462Having established the “switching” mechanism and its potential positive benefits they then set about discovering a method for increasing carnitine in muscle. It is important to remember that this had never been accomplished before.
463
464Their studies discovered two protocols. One protocol resulted in an immediate and rapid increase in muscle carnitine levels to the switching threshold. This protocol involved a highly bioavailable method that increased the influx of carnitine into muscle cells. The second protocol involved a slower day to day build up of carnitine levels and took 100 days to arrive at the switching threshold. This protocol involved lower bioavailability but more convenient methods.
465
466The first protocol might be considered by bodybuilders, athletes and fitness enthusiasts while the second might be better suited for the public at large. Introduction to Fat Oxidation
467
468To sustain life the production of energy is required. This process necessitates the acquisition & concurrent use of both oxygen and a fuel source. Fuel sources are available from either consumption of carbohydrates, fats, and rarely proteins or the release of stored fuels from within the body. The ingestion of dietary fat is an initial energy acquisition process called consumption while the process called oxidation is the final step of conversion into human energy. Between the initial process of consumption and the final step of conversion are the processes of storage and eventual release for conversion into energy.
469
470Whether the middle processes of fat storage or fat release are activated depends primarily on the state of energy balance at any point in time. If there is a surplus of fuel sources from ingested carbohydrates or fats then fat will not be released from storage in fat cells in appreciable quantities and the body will use its preferred source of energy carbohydrates followed by newly ingested fats to meet its energy requirements.
471
472When there is a surplus of energy from consumption (i.e. eating outpaces physical activity) the human body will not readily convert excess carbohydrates into fat stores but will use them for energy. Carbohydrate ingestion does not always lead to increased fat stores but may do so by being excessive and by crowding out concurrently ingested fats’ potential to be utilized as energy. As a result ingested fats during periods of surplus energy consumption will generally be stored in fat cells.
473
474Ingested fats are broken down and converted into free fatty acids, which are then stored in fat cells in a form known as triglycerides where they remain as potential energy units until called for by negative energy states.
475
476When energy balance is in a deficit (i.e. physical activity outpaces eating) fat oxidation will increase. In order for this final step of oxidative conversion into human energy to occur the middle step of release of fat stores (triglycerides) must take place. This process will result in loss of fat mass.
477
478Various hormones will trigger the release of the triglycerides from fat cells. These triglycerides, through a process labeled lipolysis are broken down into two compounds and released into the bloodstream. The first compound glycerol is primarily converted to glucose by the liver and provides energy for cellular metabolism. The second compound fatty acids are transported to the mitochondria, the portion of a cell that produces energy within each cell.
479
480This is the stage where carnitine plays an essential role in fatty acid oxidation. It is not possible for the newly liberated fatty acids to penetrate the mitochondria membrane and enter the mitochondria without the help of carnitine which acts as a transport mechanism.
481
482In general, carnitine transports long-chain acyl groups from fatty acids into the mitochondria where they are broken down through beta-oxidation in a process that ends up creating adenosine triphosphate (ATP), the energy-producing fuel.
483
484The research studies have examined the possibility that greater amounts of fatty acids could be oxidized if carnitine levels were elevated through supplements. Carnitine increases via supplementation were determined to have no effect on fatty acid oxidization.
485
486It is important to note that what I have described concerning energy balance and fat storage versus release is a generalized net (or overall) effect. Fat is constantly being stored in and released from fat cells no matter what the current energy state however the overall net effect very much depends on the state of energy balance, or as is the focus of this paper L-carnitine can be made to oxidize fat even in the presence of a positive energy balance.
487
488Summary of the two roles played by Carnitine
489
490In order to understand the relevant conclusions drawn from the Stephens Group’s research detailed from their studies herein it is necessary to understand a few elementary essentials concerning carnitine’s role in skeletal muscle fuel metabolism and briefly mention the “competing” metabolic pathway and a second function of carnitine, which is to act as a buffer during carbohydrate metabolism. When free carnitine is engaged in its role as a buffering agent for carbohydrate metabolism long-chain fatty acid oxidation diminishes.
491
492Role 1: Energy Pathway “Fatty acid transport/oxidation” – Two pools of carnitine transport
493
494The Mitochondria (the intra-cellular area where oxidation and energy production occurs) membrane is impermeable to fatty acyl-CoA (i.e. the long-chain fatty acid liberated from fat cells bonded to an enzyme named coenzyme A (CoA).) But this is not true if it is bound to carnitine. Carnitine enables the fatty acid to penetrate the membrane and it does so by binding to it and forming acylcarnitine.
495
496However there are two separate pools of carnitine that need to be utilized to move fatty acids into the mitochondria. One pool located outside of the mitochondria membrane and one pool located inside the mitochondria matrix. The one outside the mitochondria is the one that binds to fatty acids and transports them through the first of 2 layers that make up the membrane and up to the 2nd inner layer but not through the mitochondria membrane. The pool of carnitine inside the mitochondria is known as “intra-mitochondria free carnitine”. It moves to the membrane from the inside and is “handed” the fatty acyl-CoA that was delivered “to the door” by outside carnitine. The handing over process is mediated by an enzyme called Carnitine palmitoyltransferase I (CPT1) which resides on the 2nd layer of the membrane. We don’t need to introduce all the various proteins and enzymes involved in the process. Simply understand that CPT1 is akin to a bouncer at a nightclub who takes a note from someone outside the doorway and gives it to someone inside the doorway.
497
498In this way two carnitines (one from outside & one from inside the mitochondria) do the work of transporting the fatty acyl-CoA.
499
500Inside the mitochondria matrix the newly formed acylcarnitine (thanks to the hand off) is reduced back to two individual components: free carnitine and the long chain fatty acyl-CoA.
501
502So in summary the fatty acyl-CoA thanks to two carnitines has been transported into the mitochondria where it will be oxidixed and cleaved of the coenzyme A (CoA) which will take two carbon atoms with it. This process is known as beta-oxidation and results in acetyl-CoA (note: acyl goes in but acetyl comes out).
503
504Acetyl-CoA enters the TCA Cycle (ie. citric acid cycle — also known as the Krebs cycle) where energy is produced (i.e. ATP is synthesized).
505
506Role 2: Competing Energy Pathyway “Glycolysis” and Carnitine Buffer
507
508While the aforementioned metabolic pathway oxidizes fats and is the route for fatty acid metabolism, the glycolysis pathway is the carbohydrate metabolic pathway. Glycolysis is the metabolic pathway that converts glucose into pyruvate.
509
510This is accomplished in the Pyruvate dehydrogenase complex (PDC) which is a complex of three enzymes that transform pyruvate into acetyl-CoA through a process called pyruvate decarboxylation.
511
512Acetyl-CoA is the same end product arrived at through the fat oxidation pathway and is also “fed to the fire” to produce energy.
513
514Acetyl-CoA enters the TCA Cycle (ie. citric acid cycle — also known as the Krebs cycle) where energy is produced (i.e. ATP is synthesized).
515
516Under certain circumstances PDC (Pyruvate dehydrogenase complex) activity greatly increases and makes acetyl-CoA at a rate faster then the TCA cycle can consume. At that point free carnitine inside the mitochondria acts as a buffer and binds to excess acetyl from acetyl-CoA and removes it or holds it as a reservoir. This is carnitine’s other function, the removal of excess acetyl groups thereby ensuring a sufficient pool of CoA for the continuation of PDC and TCA cycle reactions.
517
518So increased PDC activity can lead to down-regulation of long-chain fatty acid oxidation because it makes use of carnitine in its second role as a buffer, leaving less carnitine available to act in its role as transporter.
519
520At the beginning of high intensity exercise (but not low intensity) skeletal muscle free carnitine content is reduced by 75% as a result of it acting as a buffer. This occurs to a greater extent in Type I muscle fibers.
521
522Skeletal muscle free carnitine content is also reduced during moderate intensity exercise when muscle glycogen content is elevated.
523
524Increased PDC activity whether it is brought about by high intensity exercise or carbohydrate metabolism results in more carnitine acting as a buffer which reduces its availability to transport fatty acid and thus long-chain fatty acid oxidation rates go down.
525
526The Switch
527
528Turning down the rate of fat oxidation
529
530Reducing the muscle free carnitine pool during conditions of high PDC flux limits the ability of CPT1 (the mediator enzyme “bouncer at the door”) to transport long-chain acyl-CoA into the mitochondrial matrix and thus the rate of fat oxidation.
531
532Support for this understanding is well established and not limited to the Stephens Group’s research. Van Loon et al. (2001) demonstrated that a 35% decrease in the rate of long-chain fatty oxidation that occurred at an exercise intensity above 75% VO2 max,was paralleled by a 65% decline in skeletal muscle free carnitine content.
533
534Roepstorff et al. (2005) showed a 2.5-fold decrease in the rate of fat oxidation, compared to control, during moderate intensity exercise (65% of VO2 max) when free carnitine availability was reduced by 50% as a result of pyruvate, and therefore acetyl-CoA, production being increased as a result of pre-exercise muscle glycogen content being elevated.
535
536Further support for the understanding that free carnitine availability may limit fat oxidation comes from Achten & Jeukendrup, (2004). Muscle free carnitine content has been shown to decrease from approximately 11 to below 5.5mmol (kg dm)-1 between the exercise intensities of 60 and 80% of VO2 max, and it has been calculated that maximal and minimal fat oxidation rates during exercise are achieved at exercise intensities of around 65% and greater than 80% of VO2 max, respectively.
537
538Reversing the Switch – Turning up the rate of fat oxidation & turning down the rate of carbohydrate oxidation
539
540Putmanet al. (1993) supply evidence by demonstrating that during bicycle exercise at 75% of VO2 max to exhaustion, both muscle free carnitine content and fat oxidation rates were markedly higher when pre-exercise muscle glycogen content was lowered compared to control.
541
542In one of the Stephens Group’s studies they found that a 15% increase in skeletal muscle carnitine content… resulted in a 30% decrease in muscle PDC activity and a 40% decrease in muscle lactate content, leading them to conclude “These results suggest that an acute increase in human skeletal muscle total carnitine content results in an inhibition of carbohydrate oxidation in conditions of high carbohydrate availability, due to a carnitine-mediated increase in fat oxidation.”
543
544As an explanation
545
546Philip Randle in the 1960s undertook a series of landmark and controversial studies detailing the workings of the balance between fatty acid oxidation and glucose oxidation in what he called the glucose–fatty acid cycle (Randle et al. 1963, 1964; Garland et al. 1963; Garland & Randle, 1963). Therein he laid down the fundamental concept of reciprocal substrate competition between glucose and non-esterified fatty acids (the major fuels that are oxidized to provide ATP in mammals) in normal physiology in muscle.
547
548In describing the competition between glucose oxidation and fatty acid oxidation he specified that an increase in beta-oxidation would result in an elevation of muscle acetyl-CoA concentration and, consequently, an increase in muscle citrate and glucose-6-phosphate content. This, in turn, would result in the down-regulation of carbohydrate flux [activity], due to product inhibition of PDC, phosphofructokinase and hexokinase, respectively.
549
550The Stephens Group acknowledge Randle’s important work in their elaboration of the results of their own study stating “In support of [Randle’s description] muscle long-chain acyl-CoA content returned to basal overnight during the L-carnitine infusion visit (whereas it remained suppressed during the control visit), which suggests that Beta-oxidation was indeed increased…while there was a 30% decrease in muscle PDC activity”
551
552Athletic Performance, fatigue & the first few seconds of muscle contraction
553
554It is well established that there is a lag in oxidative ATP delivery at the onset of exercise and muscular contraction. This is attributable to a lag in mitochondrial ATP production brought about by a lag in PDC activity which results in an insufficient acetyl-CoA supply to match the demands of the TCA cycle (Krebs cycle – energy producing). The fuel supply is lacking at that moment in time.
555
556According to a study by Roberts et al. (2002) a lag in acetyl group provision (predominately in the form of acetylcarnitine) occurs during the initial 20 seconds of contraction. Remember acetylcarnitine is created as a result of its role as a buffer during high PDC activity and held as an acetyl reserve. If PDC activity is not high enough at the start of contraction there will be very little acetyl group available to feed the cycle that produces energy (ATP).
557
558So at the onset of contraction there is a lack of fuel in the form of acetyl groups.
559
560“This is a rate-limiting step in the rate of rise in mitochondrial ATP re-synthesis in skeletal muscle at the onset of exercise, which in turn will dictate the magnitude of oxygen-independent ATP delivery, and thereby the rate of fatigue development during intense exercise.” – Stephens Group
561
562This can be overcome by “priming” through manipulating muscle carnitine pools at rest so as to make available sufficient energy substrate and by activating the PDC prior to the event by warming up before intense exercise.
563
564The Stephens Group Research: Summary of Findings
565
566How to increase muscle carnitine
567
568Plasma carnitine is not specifically lacking The transport mechanism and membrane gradient for carnitine flow into muscle cells are restrictive Increasing the amount of carnitine is of no value in and of itself Increasing the transport mechanism/membrane gradient + the amount of carnitine = increase in muscle carnitine The methodolgy for increasing flow of carnitine in to cells is via changing the membrane permeability to allow more carnitine transport Methodology
569
570Insulin is a method for effecting this increased flow Intravenously administered L-carnitine + insulin = increased carnitine in muscle cells There is a threshold concentration for the stimulatory effect of insulin on skeletal muscle accumulation blunts PDC activity (carbohydrate oxidation) reduces muscle lactate content increases glycogen content in muscle (i.e reduces oxidation of glucose in favor of storage) reduces muscle glycolysis increases fat oxidation Results: Using this methodology carnitine content increases by 13% to 15% and:
571
572Alternative Methodology
573
574For the reason that the determined insulin threshold is low enough to be reached via non-pharmacological methods, oral ingestion of glucose may be used. For the reason that the carnitine turnover rate in skeletal muscle is low (190 +/- 20 hours) daily carnitine increases will result in a continued build up of total muscle carnitine. This allows the use of low bioavailable methods such as daily ingestion of oral carnitine w/ glucose load to increase carnitine in muscle at an incremental rate such that within 100 days carnitine content will have increased by 10%. blunt PDC activity (carbohydrate oxidation) reduce muscle lactate content increase glycogen content in muscle (i.e. reduce oxidation of glucose in favor of storage) reduce muscle glycolysis increase fat oxidation Results: This amount of carnitine is sufficient to:
575
576How do you increase carnitine in muscle?
577
578Studies have consistently failed to increase skeletal muscle carnitine content either through oral supplementation or intravenous L-carnitine administration. Watcher et al (2002) fed 2 grams of L-carnitine twice a day for 3 months to normal people and failed. Similar studies by Barnet et al. (1994) and Vulkovich et al. (1994) demonstrated similar failures with oral feedings of l-carnitine for 3 months.
579
580Intravenous infusion of L-carnitine for up to 5 hours similarly failed to have any effect on muscular carnitine content (Brass et al. (1994); (Stephens Group, Insulin stimulates… (2006)).
581
582How carnitine is normally transported into the cell
583
584The reason for these failures is very simple. Normal people have no deficiency in circulating plasma levels of carnitine. What they have is a fully saturated transport mechanism. No amount of carnitine load is sufficient without a concurrent increase in the ability of the transport mechanism to transport carnitine across the cellular membrane.
585
586The cellular membrane is a lipid bilayer easily permeable to water molecules and a few other small, uncharged, molecules such as oxygen and carbon dioxide but little else. The cellular membrane is not permeable to ions such as K+, Na+.
587
588In the normal course of things molecules and ions move about spontaneously down what is known as their concentration gradient (i.e., from a region of higher to a region of lower concentration) by diffusion.
589
590Molecules and ions are capable of moving against their concentration gradient, but this process requires a process known as active transport.
591
592It is the active transport that is lacking in regard to carnitine movement and unless this is changed additional carnitine will not be allowed to enter the cell.
593
594Active transport is the pumping of molecules or ions through a membrane against their concentration gradient. It requires: a transmembrane protein (usually a complex of them) called a transporter and energy. The source of this energy is ATP.
595
596The transmembrane protein responsible for carnitine transport into skeletal muscle is OCTN2. The half-saturation concentration of L-carnitine uptake by OCTN2 is 4.34 umols (Tamai et al. (1998)). In the normal state skeletal muscle carnitine uptake is saturated since plasma total carnitine concentration is 50 umols.
597
598OCTN2 has a high affinity for carnitine and sodium ions (Na+) and readily binds to both and so carnitine is transported into skeletal muscle against a substantial concentration gradient via a transport process involving sodium Na+ flow. In essence carnitine hitches a ride on OCTN2 which hitches a ride on Na+.
599
600A detailed description of this process is beyond the scope of this article so a general reduction will suffice. One method of direct active transport across the cellular membrane is the Na+/K+ ATPase pump.
601
602The concentration of potassium ions (K+) is as much as 20 times higher inside the cell then outside. Conversely, the fluid outside the cell contains a concentration of sodium ions (Na+) as much as 10 times greater than that within the cell. Because of this difference a concentration gradient amenable to flow exists and the Na+/K+ ATPase pump effects the transfer of these two ions pushing out 3 Na+ ions for every 2 K+ ions pumped back into the cell. This activity establishes a net charge across the plasma membrane with the interior of the cell being negatively charged with respect to the exterior.
603
604So with this basic understanding that OCTN2 is a cotransporter of sodium & carnitine and that under normal conditions it is fully saturated and thus unable to benefit further carnitine inflow via Na+/K+ ATPase pump activity, lets examine how insulin overcomes this equilibrium and brings about an increased inflow of carnitine into skeletal muscle.
605
606How insulin increases the flow of carnitine into muscle
607
608The Na+ dependent, active transport of carnitine into human skeletal muscle is mediated via a high-affinity, transporter OCTN2.
609
610The Stephens Group found that the combination of increased carnitine and increased insulin (above a threshold) increased skeletal muscle OCTN2 mRNA expression by 2.3 fold (Stephens Group, Insulin stimulates… (2006)) in addition to increasing the activity of Na+/K+ ATPase pump. This results in an increased availability of transporter which potentially increases the amount of carnitine that may be carried into the muscle cell.
611
612The action of insulin however is most important in changing the membrane permeability in favor of carnitine inflow.
613
614It has been demonstrated that the Na+ dependent uptake of other nutrients into skeletal muscle is increased by insulin, for example amino acids (Zorzano et al. 2000) and creatine (Green et al. 1996; Steenge et al. 1998).
615
616Insulin is able to increase the flow of carnitine into skeletal muscle as follows.
617
618Insulin increases Na+/K+ ATPase pump activity by increasing translocation (or movement) of alpha2 and beta1 pump subunits from an intracellular storage site to the plasma membrane (Sweeney & Klip, 1998), and through an increase in the sensitivity of the Na+/K+ ATPase pump to intracellular Na+ (Clausen, 1986, 2003; Ewart & Klip, 1995).
619
620OCTN2 has equal affinity for sodium ion (Na+) and carnitine and bonds to both. With an increased Na+/K+ ATPase pump activity brought about by an increase in circulating insulin concentration intracellular Na+ concentration is lowered which increases the electrochemical gradient for Na+ and therefore increases Na+/carnitine cotransport.
621
622This results in an increase of carnitine inside the muscle cell.
623
624Methodology and results
625
626The Stephens Group undertook a series of experiments building on each to create an overall understanding. In Insulin stimulates L-carnitine accumulation in human skeletal muscle, they were able to increase muscle total carnitine content by 13%. They achieved this by using what I will call an “overkill amount of L-carnitine” administered by infusion. They administered a 15mg/kg bolus w/in the 1st 10 minutes rapidly achieving a supraphysiological plasma concentration of about 500 umol/L. This was followed by 10mg/kg infused over the next 290 minutes to maintain hypercarnitinemia.
627
628In addition they infused insulin at a dose I will call an “overkill amount”. The aim of study was to determine whether insulin could increase Na+/dependent skeletal muscle carnitine up-take in healthy human subjects as a result of increasing Na+/K+ ATPase pump activity. They were very much successful. The positive results of the study are incorporated in the previous section.
629
630Using an identical protocol and intravenous L-carnitine & insulin amounts they undertook another study reported in An Acute Increase in Skeletal Muscle Carnitine Content Alters Fuel Metabolism in Resting Human Skeletal Muscle with the broader aim of determining the effect that an increase in skeletal muscle carnitine content would have on the integration of muscle fat and carbohydrate oxidation during and after hyper-insulinemia.
631
632As in the previous study total carnitine content increased in skeletal muscle, this time by 15%.
633
634This resulted in a 30% decrease in muscle PDC activity (carbohydrate metabolism) and a 40% decrease in muscle lactate content. After an overnight fast, muscle glycogen and LCA-CoA (long-chain acyl-CoA) content had increased by 30% and 40% respectively, in the carnitine group compared with control. The difference between the control and carnitine visits was not attributable to a difference in the amount of carbohydrate administered.
635
636“Taken together, these findings lead us to conclude that the increase in muscle carnitine content observed in the present study inhibited glycolytic flux (decrease in lactate) and carbohydrate oxidation at the level of the PDC, thereby diverting muscle glucose uptake toward glycogen storage (nonoxidative glucose disposal).”
637
638“The reciprocal relationship between carbohydrate and fat oxidation in skeletal muscle would suggest that the apparent decrease in carbohydrate flux observed was the result of, or resulted in, an increase in fat oxidation. Thus, these findings could be of major importance in the treatment of insulin-resistant states, such as obesity and type 2 diabetes, because both conditions are associated with an impaired ability of skeletal muscle to oxidize fatty acids, both at rest and during exercise. Furthermore, reducing or preventing intramuscular lipid accumulation increases insulin sensitivity.”
639
640The implications of these results should be clear and having read the previous portions of this article and examined the figures, self-explanatory. To reiterate the decrease in PDC activity indicates a substantial drop in carbohydrate metabolism, while the decrease in muscle lactate indicates a decrease in glycolysis activity. The increase in muscle glycogen storage given the constants of the study indicate that glucose was preferentially stored not metabolized. This also indicates that existing muscle glycogen stores where enhanced rather then drawn upon.
641
642The reciprocal relationship between carbohydrate oxidation and fat oxidation indicates that fuel sources utilized for energy where fats.
643
644The meaning of the one item that may not be readily apparent is that of LCA-CoA (long-chain acyl-CoA) increasing overnight. Remember from the early discussion in this article that carnitine transports long-chain acyl groups from fatty acids into the mitochondria where they are broken down through beta-oxidation. The fact that these groups had increased strongly indicated that carnitine is increasing its activity as a transporter in fatty acid oxidation and that fatty acid oxidation is increased.
645
646In the words of the Stephens Group in an overall review of their work:
647
648“…the apparent reduction in glycolytic flux and carbohydrate oxidation… (decreased PDC activity and lactate content, and increased glycogen accumulation), in the face of high carbohydrate availability, could have been caused by a carnitine-mediated increase in skeletal muscle long-chain fatty acid oxidation, i.e. an increase in long-chain acyl-CoA translocation into the mitochondrial matrix via CPT1, resulting in an increase in beta-oxidation.
649
650According to Randle’s glucose–fatty acid cycle (Randle et al. 1963, 1964; Garland et al. 1963; Garland & Randle, 1963), a concept proposed in the 1960s from experiments involving rat heart and diaphragm muscle, an increase in beta-oxidation would result in an elevation of muscle acetyl-CoA concentration and, consequently, an increase in muscle citrate and glucose-6-phosphate content. This, in turn, would result in the down-regulation of carbohydrate flux, due to product inhibition of PDC….
651
652Indeed, the decrease in PDC activity observed in our study was paralleled by a reduction in muscle lactate content and resulted in an accumulation of muscle glycogen overnight, conditions which are both consistent with the premise that glycolytic flux, and therefore carbohydrate oxidation, was inhibited. In support of this… muscle long-chain acyl-CoA content returned to basal overnight during the l-carnitine infusion visit (whereas it remained suppressed during the control visit), which suggests that beta-oxidation was indeed increased.”
653
654Alternative Methodology
655
656Obtaining a lower insulin threshold
657
658In an attempt to discover the lowest amount of insulin needed to drive carnitine into muscle and activate the switch from carbohydrate oxidation to fatty acid oxidation, the Stephens Group undertook a study the reports of which are discussed in A threshold exists for the stimulatory effect of insulin on plasma L-carnitine clearance in humans.
659
660They reasoned that while their previous studies with insulin infusion in an amount in the upper physiological range were successful, it would be difficult to achieve by dietary means alone.
661
662They discovered that administered insulin will not stimulate muscle carnitine retention unless a serum insulin concentration greater than 90 mU/l is achieved during hypercarnitinemia. This level was substantially lower (and obtainable via dietary means) then the previous high concentrations used and stimulated muscle carnitine transport to a similar degree.
663
664Extrapolating from data, skeletal muscle total carnitine content in this study with this threshold insulin amount would have been increased by about 10%.
665
666Orally ingesting lower bioavailable L-carnitine together with high glycemic index carbohydrates
667
668The Stephens Group in a study the results of which are reported in Carbohydrate ingestion augments L-carnitine retention in humans, investigated whether physiologically significant increases in skeletal muscle carnitine content can be achieved through the use of L-carnitine feeding in conjunction with a dietary-induced elevation in circulating insulin.
669
670They examined serum insulin levels achieved from glucose ingestion, the plasma total carnitine level and the urinary total carnitine excretion levels in order to determine the amount of carnitine taken up in muscle by performing both a one day study and a 14 day study.
671
672Both studies used oral ingestion of:
673
6744.5 g L-carnitine L-tartrate (3 g L-carnitine) dissolved in 200 ml of water
675
676followed by
677
67894 g of simple sugars (CHO) either ingested twice at 1 hour & 4 hours after L-carnitine ingestion as in the 14 day study or as in the one day study four time across a 5 hour period.
679
680Serum insulin concentrations during the period when simple sugars were ingested are graphed below. Surprisingly peak serum insulin concentrations of about 70mU/l proved to be sufficient.
681
682The graph below indicates that the rise in insulin eliminated carnitine from plasma. The control subjects had more carnitine in plasma then those on the protocol. See below.
683
684If the carnitine is not in plasma is it excreted? The graph below indicates that urinary excretion rates were lower over the measured 14 days in those following the protocol. See below.
685
686“We suggest, therefore, that the lowering of plasma total carnitine (TC) concentration occurring immediately following CHO ingestion, and the lower urinary TC excretion during the CHO visit, collectively indicate that an increase in whole body carnitine retention occurred when L-carnitine feeding was accompanied by CHO ingestion. Given that skeletal muscle is the major site of carnitine storage within the body, and that maintaining hypercarnitinemia for 5h in the presence of hyperinsulinemia increases skeletal muscle TC accumulation (other Stephens Group studies), it is not unreasonable to suggest that this greater retention occurred mainly in this tissue.”
687
688Extrapolating an accumulation strategy
689
690Given that the increase in muscle carnitine content following a single dose, or 2 weeks, of L-carnitine feeding in the presence of elevated circulating insulin is likely to be small due to the poor bioavailability of orally administered L-carnitine (less then 20%), muscle carnitine accumulation was estimated indirectly from measurements of plasma and urinary carnitine concentration.
691
692In this study 3 grams of carnitine results in at most 560 mg of absorbable plasma carnitine.
693
694“Assuming all absorbed carnitine was either taken up into skeletal muscle tissue or excreted in the urine, it can be calculated that L-carnitine feeding in conjunction with CHO ingestion would have increased skeletal muscle total carnitine concentration by a further 0.1% (i.e., 60 mg) compared with L-carnitine ingestion alone.”
695
696In fact “urinary total carnitine excretion was on average 70 mg/day lower in the CHO group over the 14 days of study. Consequently, if maintaining a daily L-carnitine feeding regime with CHO has an additive effect on muscle carnitine content, L-carnitine feeding for 100 days could increase muscle carnitine content by an additional 10%, which we believe could have a significant metabolic impact in contracting skeletal muscle.”
697
698In the other comprehensive Stephens Group study they found that muscle total carnitine content was not reduced 24 h after a 15% increase, suggesting that a daily increase in muscle carnitine content can be maintained. In addition release of carnitine from skeletal muscle is a slow process, with skeletal muscle carnitine turnover time of 190 +/- 20 hours (Rebouche (1984)).
699
700“Taken together with the maintained effect on whole body total carnitine retention observed in the 14 day study, these findings would suggest that daily L-carnitine and carbohydrate administration could well have an additive effect on skeletal muscle total carnitine accumulation. Importantly, if L-carnitine supplementation is to be used as a tool to modify skeletal muscle energy metabolism, the findings in the 14 day study also suggest that, at most, only two 500-ml CHO drinks (2 x 94 g CHO) are required to achieve the effect on L-carnitine retention.”
701
702In conclusion:
703
704“…muscle free carnitine availability becomes limiting to carnitine palmitoyltransferase I (CPT1) at a concentration of about 6 mmol/kg dry muscle….
705
706Thus, assuming the average 70 mg/day retention in the present studies resided within skeletal muscle and that daily L-carnitine/carbohydrate feeding for 100 days would have an additive effect, then muscle carnitine content would increase by about 2 mmol/kg dry muscle, which could alleviate the decline in fat oxidation rates routinely observed at exercise intensities above 70% VO2 max, which could be of major relevance to exercise performance due to the sparing of muscle glycogen.
707
708In line with this theory, increasing skeletal muscle carnitine availability has been reported to delay fatigue development by 25% in rat soleus muscle strips in vitro (Brass (1993)).”
709
710Further more it is worth reiterating that the Stephens Group has demonstrated in the study involving intravenous L-carnitine administration that a 15% increase in skeletal muscle carnitine content, achieved during hyperinsulinemia, resulted in a 30% decrease in muscle PDC activity and 40% decrease in muscle lactate content compared with control. Furthermore, following an overnight fast, muscle glycogen and long-chain acyl-CoA content was 30% and 40% greater than control, respectively, despite carbohydrate administration over the previous 24 hours being exactly the same.
711
712This is the first study to demonstrate that the retention of orally supplemented L-carnitine can be increased if accompanied by carbohydrate ingestion and that this retention is likely to reside in skeletal muscle, because insulin is known to stimulate muscle total carnitine accumulation. “These findings could have a significant effect on the integration of fat and carbohydrate oxidation in contracting skeletal muscle.”
713
714Final Note
715
716An immediate threshold amount of increase in muscle carnitine concentration can be had with administration of highly bioavailable Synthetine™ (sterile L-Carnitine) with insulin or oral ingestion of two high glycemic index drinks such as SyntheDEXTRIN™ (Maltodextrin Pure Carbohydrate).
717
718An accumulation strategy of daily oral ingestion of low bioavailable l-carnitine with oral ingestion of two high glycemic index drinks such as SyntheDEXTRIN™ (Maltodextrin Pure Carbohydrate) will lead to a threshold amount of muscle carnitine concentration within 100 days.
719
720These strategies should enable reversing the switch – Turning up the rate of fat oxidation & turning down the rate of carbohydrate oxidation.
721THE SCIENCE BEHIND: ‘SYNTHEROL – SITE ENHANCING OIL’
722
723Syntherol™ is a caprylic acid based proprietary formulated sterile site enhancement oil. It is manufactured by a major pharmaceutical company in accordance with the highest level of manufacturing practices. No other seller of site enhancement oil can guarantee that the product they sell is sanitary, hygienic, bottled and sealed under pharmaceutical conditions that assure the health and wellbeing of the end user..
724
725Syntherol™ is a proprietary formula whose constituent parts do not deviate from that which is necessary to effect muscular change as described in the science summarized herein. As a result Syntherol™ is highly effective.
726
727No other site enhancement oil currently available can claim to be both pharmaceutically sterile and scientifically effective.
728
729What follows is a summary of the science that makes Syntherol™ a muscle building agent and the basic protocol developed by IFBB Pro Big A in regard to applying Syntherol™. What is Fascia?
730
731The fascia is not extremely well studied. It is basically a three-dimensional matrix of tissue which may be thought of as both a body casing or sheath (think about a tight rubber body suit) and a separate deeper tissue which penetrates muscle and is attached to muscle via septa (or offshoots).
732
733Fascia seems to function as a way to transmit applied force information from one muscle grouping to the next. Fascia also seems to function as a method by which the force generated by load is applied to muscle fiber and reduced in bone.
734
735When a muscular contraction occurs fascia or rather fascicle (a fascia bundle of muscle fibers) curves. The greater the contraction the greater the curvature. When this curving takes place pressure is produced on the concave side. Curving of the fascicle increases intramuscular pressure and therefore affects blood flow. In addition fascicle curving reduces the force transmitted to the bone.
736
737So a contracted muscle which bulges can be understood to have increased pressure inward.
738
739There really are two distinct classes of fascia. The superficial fascia (the body wrap) is connected to the dermis and the upper torso is enveloped in this tissue from the pectorals to the rib cage area & stomach, up under the lats, from the pectorals up over the delts and down the arms.
740
741This body sheath is capable of transmitting information to various parts of the body concerning the amount of pressure that is occurring on other regions of the body as a result of force generation.
742
743The second class of fascia is specific to the region and yet this deeper tissue also connects to other regions as described above and transmits force/pressure data. The pectoral fascia is firmly connected to the underlying muscle by many intramuscular septa, which originate from the inner surface of the fascia and penetrate between the muscular fibers, dividing the muscle itself into many bundles.
744
745Pectoral fascia thickness varies greatly between people. The lower pectoral fascia is thicker then the upper with the upper pectorial region averaging .49mm in thickness and the lower averaging .60mm in thickness.
746
747There is a significant deviation from these averages in both the thickness & pliability among individuals. One study found lower pectoral fascia thickness varied from a high of .99mm to a low of .24mm.
748
749So from this brief summary we can understand that:
750
751There is a wide variability in fascia thickness and this in part can explain the difference in fullness of muscle bellies between individuals that lift weights. We can visualize that application of oil will apply pressure to the fascia as it creates curvature even at rest.
752
753We can further visualize that application of oil will increase pressure in the region and as a result increase blood flow.
754
755Consequently if you follow weightlifting lifting techniques that maximize the generation of peak force on a targeted muscle you will also be creating additional maximum pressure inside the muscle worked.
756
757Below are three images showing the superficial fascia (the body wrap); the pectoral fascia; and an image demonstrating how fascia coordinates balance and contraction between the two pectoral sides.
758
759Autopsy of superficial fascia pectoral fascia
760
761Coordinated force transmission across fascia
762
763References:
764
765The pectoral fascia: Anatomical and histological study, Antonio Stecco, Journal of Bodywork and Movement Therapy (2008)
766
767In vivo determination of fascicle curvature in contracting human skeletal muscles, Tadashi Muramatsu, J Appl Physiol 92:129-134, 2002
768
769Anatomy and Clinical Significance of Pectoral Fascia, Lin Jinde, M.D., American Society of Plastic Surgeons Volume 118, Number 7 Pectoral Fascia
770
771Fascia Stretching
772
773Therapists utilize deep and painful tissue manipulation techniques to loosen up stiff fascia, which can impinge certain areas. They call their techniques myofascial release.
774
775In the world of bodybuilding John Parrillo may have been the first one to use the term “fascial stretching.” He developed a technique which basically involved pumping the muscle with blood to engorge it, followed by extreme and painful stretching of the engorged muscle and then a pose to you cramp style of holding the engorged muscle in a contraction. He even went so far as to create and sell fascia stretch machines.
776
777Tom Platz appears to be one of the earliest practitioners of this technique. He would use the entire weight stack of the old school leg extension machine (where you could lay flat if you wanted) and he would pump out as many full and then partial reps as he could followed by assisted reps. Then he would immediately get on the floor on his knees and lay back grimacing in pain and he would hold this deep stretch. Then do it again…
778
779The problem with this technique, although beneficial, is that the pressure which is being applied to curvature of the fascia is short lived albeit intense.
780
781It is likely that fascia will become more pliable (it is simply layers of collagen and elastin in a water-based matrix) the longer it is held in a curved position. This is the reason applied oil has proven superior.
782
783Clearance rate of applied oil
784
785I was once wondering about the clearance rate of oils. I have seen it stated at various times that MCT (Medium Chain Triglycerides) could be deadly because it stays around forever.
786
787No it doesn’t. I went through a lot of studies and although there is variability among animal models it seems MCT oil (Fractionated coconut oil) possesses about a one week half-life in muscle and the rate of disappearance remains linear.
788
789The key determinant seems to be the general viscosity of the oil. Here is a good example:
790
791From, Intramuscular rate of disappearance of oily vehicles in rabbits investigated by gamma-scintigraphy, Kirsten Schultz et al, International Journal of Pharmaceutics 169 (1998) 121-126
792
793Viscosities and muscular disappearance rates of various oily vehicles
794
795Oily vehicle Viscosity at 37°C T1/2 Ethyl oleate 3.9 10 days Fractionated coconut oil 15 1 week Sesame oil 35 1 month Arachidis oil 35.2 23 days Castor oil 286 Indefinitely Apparently the volume of the oil applied doesn’t effect the clearance rate. That remains constant.
796
797In addition both fractionated coconut oil (MCT) and sesame oil spread approximately 25% along the muscle fibers (beneath the fascial sheaths) during the first 24 hours after administration (primarily in the first few minutes) and then virtually no more spreading. So MCT oil is effective at creating a volume depot capable of fascial stretching.
798
799More importantly the studies show that MCT oil is not deadly. It has half the viscosity of sesame oil so if it gets into the blood stream it probably isn’t going to clog any arteries or cause blockages in and around the heart. In fact MCT oils ingested orally pass into the body without much change and circulate in plasma eventually acting as an energy substrate with no apparent health concerns.
800
801It has a half-life (i.e. degradation rate) of a week and a linear continual clearance rate so MCT oil will not stay around for a long period of time. Only about 1% remains after 6 weeks.
802
803What determines absorption of administered oil & how is it absorbed?
804
805Lymphatic (minor role)
806
807A maximum of 5% of the applied dose of sesame oil and Viscoleo (brand of MCT oil) in rats and dogs was accounted for via lymphatic absorption (Svendsen and Aaes- Jorgensen, 1979)….Lymphatic absorption might be expected to take place more efficiently from the subcutaneous layers than from the intramuscular application sites, since the lymphatic system is better developed in the former region (Ballard, 1968). Although some absorption into the lymphatic system may occur it appears less likely that this route of absorption plays a dominant role in the clearance of oil vehicles.
808
809Surface area
810
811The surface area of the oil depot is likely to affect the clearance of the oil vehicle from the application site. Thus, the distribution of the oil vehicle at the application site can be an important variable. The spreading characteristics of the oil vehicle appear to be influenced by the viscosity of the oil (Howard and Hadgraft, 1983). …the more viscous oil the more resistant to spreading at the application site and consequently a slower clearance rate would be expected.
812
813Other Factors
814
815Biological and physiological factors such as vascularisation (Zuidema et al., 1988) and body movement (Ballard, 1968) might also influence the absorption rate of the oil vehicles.
816
817Phagocytosis (the cellular process of engulfing solid particles by the cell membrane) might constitute another possible absorption mechanism (Ballard, 1968). Phagocytosis is likely to be related to the tissue response to the applied oil material (Ballard, 1968).
818
819Metabolic degradation of oil vehicles has been suggested by Svendsen and Aaes-Jorgensen (1979) to play a role in the removal of oil vehicles from the site of application. As a result of the inflammatory response, several enzymes might be present at the application site. Degradation of oil vehicles mediated by lipases might therefore also contribute to the disappearance rate of oil vehicles where the rate of degradation might be influenced by the composition of the oil vehicles:
820
821Source: Determination of the disappearance rate of iodine-125 labelled oils from the application site after intramuscular and subcutaneous administration to pigs, Susan Weng Larsen et al, International Journal of Pharmaceutics 230 (2001) 67-75
822
823For the specific studies written by the authors mentioned above, see the references cited in the aforementioned study.
824
825Caprylic Acid (MCTs)
826
827So what happens when MCT oil moves into the blood stream?
828
829It is a good thing and is a significant dietary aid. It has a “direct inhibitory effect on fat storage in adipocytes under conditions that normally favor lipogenesis”.
830
831Medium-chain fatty acids are unique because they are metabolized differently from either long-chain fatty acids or carbohydrates. Dietary Medium-chain triglycerides (MCT) have been found to inhibit body fat mass growth in both animals and humans. They do this through two distinct mechanisms.
832
833The first mechanism involves MCTs in their role as an energy source. They are rapidly absorbed and oxidized in the liver, and used as a quick source of energy, which reduces the circulating fatty acids available to adipocytes (fat cells). Unlike long chain fatty acids (LCTs), they are able to pass through the mitochondrial membrane without the assistance of the primary mode of transport, carnitine. As a result MCTs are capable of quickly and directly entering into a metabolic process that results in the production of ketones thereby increasing available energy.
834
835The second mechanism involves the portion of MCTs that do find there way into adipocytes (fat cells). However they are not stored but rather act to suppresses lipogenesis (fat storage) by inhibiting gene expression. Technically they inactivate the key adipocyte transcription factor, peroxisome proliferator-activated receptor y (PPARy). Simply stated caprylic acid (MCTs) induces a metabolic state in adipocytes (fat cells) mimicking a fasting condition without actual hormone/nutrient deprivation. In fact they are able to do this even in the presence of insulin and glucose (conditions that normally favor lipogenesis (fat storage).
836
837“Compared to the pharmaceutical inhibitors of lipogenesis, the effects of octanoate [caprylic acid] can be considered as moderate and yet might be more desirable for physiological regulation of body fat mass without adversely affecting normal fat tissue functions.” – *
838
839    – Modulation of adipocyte lipogenesis by octanoate: involvement of reactive oxygen species, Wen Guo, Weisheng Xie and Jianrong Han, Nutrition & Metabolism 2006, 3:30
840
841This is one reason why MCT oil works well in those in pre-contest mode. It is used for site enhancement but it also acts as an energy substrate with very little fat storage and a positive effect as an inhibitor of lipogenesis.
842
843Why site application of Caprylic Acid may work (In addition to increasing fascia pliability).
844
845STUDY ** The study set out to determine what effect if any does an extract of the bark of the tree Eucommia ulmoides have on creating synergism between sex steroids receptors, sex hormones and lipids derived from plants.
846
847What they discovered is that the extract demonstrated androgenic activities by weakly activating Androgen Receptors (AR) in a dose-dependent manner. The scale that is used to measure androgenic activity is such that a saturation dose of the androgen receptor’s native ligand (testosterone) will produce a 100 fold Luciferase assay (LUC) activity. The extract produced a 6.4 fold LUC activity.
848
849Androgenic of Eucommia ulmoide by itself
850
851The extract also demonstrated a weak activation of the estrogen receptor.
852
853However when they combined a saturation dose of testosterone and the extract they found synergy. When a saturation dose of androgen, either DHT or testosterone is added together with the extract the increases in Androgen Receptor (AR)-mediated reporter gene expression goes up beyond what the saturation dose of testosterone or DHT alone could produce. The synergy with DHT moved up above the 200% mark while the synergy with testosterone moved androgen receptor activity close to the 240% mark. The extract acted as an amplifier of androgen receptor transcriptional activity.
854
855In the words of the study “This is highly unusual as normally, androgen mediated AR transcriptional capacity, akin to all ligand dependent steroid receptors, plateaus at saturating doses of its cognate ligand.”
856
857So to restate, testosterone activates androgen receptor transcriptional activity to their normal capacity of 100%. The extract by itself weakly activates the androgen receptor by 6%. Together the extract and testosterone activate the androgen receptor and propel it to transcribe at a rate more than twice what it is normally capable of. In this case increasing activity to 240%.
858
859A similar effect was demonstrated on the estrogen receptor.
860
861Synergy between testosterone and Eucommia ulmoide
862
863Having demonstrated a synergistic relationship in human and mammalian cells they carried out a second study this time in vivo.
864
865To test the anabolic effect in vivo prostate growth was measured in an animal model (rats). Saturation dose for testosterone defined as 5mg was administered IM and 50mg of E. ulmoides (EU) extract was given orally. The results graphed below again indicate that extract amplifies testosterones effect on the androgen receptor-mediated transcriptional events that lead to growth.
866
867In vivo anabolism between testosterone and Eucommia ulmoide
868
869The study then attempted to ascertain the components of the extract responsible for the synergism. To this end they fractionated the extract into components and found two active components. One component was found to exert its effect (labeled phytoandrogenic activity by the authors) on the Androgen Receptor by changing its binding characteristics. That compound is completely unrelated to caprylic acid.
870
871The second active fraction contained 8-carbon polysaturated fatty acid, caprylic acid, and other lipids. In the words of the authors:
872
873“Bioassays using pure caprylic acid and other polysaturated fatty acids (PFAs) correlated with the augmenting effect of E. ulmoides on the AR [androgen receptor] in varying degrees. Ethanolic extract of coconut (Cocos nucifera) flesh, rich in C-8 caprylic acid and other polysaturated fatty acids, replicated the hormone potentiating effect of both E. ulmoides extract and pure caprylic acid in AR bioassays (data not shown).”
874
875In my words,
876
877Equally effective were:
878
879Ethanolic extract of coconut;
880
881Pure caprylic acid; and
882
883E. ulmoides.
884
885The major constituent in all three is caprylic acid which as the authors show in the figure below had the strongest augmenting effect of all the lipids.
886
887So a blend of PFAs in ethanolic extract of coconut the vast majority of which is caprylic acid replicated the hormone potentiating effect of E. ulmoides extract whose primary constituent is caprylic acid which all by itself in pure caprylic acid form replicated the hormone potentiating effect of E. ulmoides extract.
888
889Caprylic acid is the strongest lipid augmenter of androgen receptors
890
891In an attempt to explain why caprylic acid had an augmenting effect the authors state:
892
893“Okadaic acid, a known phosphorylation promoter, is able to strongly augment androgen-dependent AR activity. Interestingly, fatty acids can also promote phosphorylation. One instance is oleic acid, a C-18 cis-monosaturated fatty acid. It is possible that AR [androgen receptor] and ER augmentation by both E. ulmoides extract and caprylic acid arise from a common tripartite synergism between the steroid receptors, sex steroids and fats, based on a phosphorylation mechanism.”
894
895The action of caprylic acid labeled a “lipid augmenter” by the authors is postulated to result from increased phosphorylation. This differs from the action of the other non-caprylic component labeled a “phytoandrogen” which changes the ligand binding characteristics.
896
897The study concludes, “the novel discoveries reported in this study add phytoandrogens and lipidic augmenters to the emerging list of hormomimetics (such as phytoestrogens) known to exist in plants. Pharmaceutical utility of lipidic augmenters in the treatment of hypogonadal conditions such as menopause or andropause could be exploited based on this mechanism of tripartite synergism. The link between excess dietary lipids, hyper-androgenism and hormone-related disorders should also be further explored in the light of these findings.”
898
899** Source: Novel phytoandrogens and lipidic augmenters from Eucommia ulmoides, Victor YC Ong and Benny KH Tan, BMC Complementary and Alternative Medicine 2007, 7:3
900
901Site administration of sterile caprylic acid
902
903MCT oil’s primary constituent is caprylic acid. Consuming it orally or administering IM should have the effect of synergizing with natural levels of testosterone (hopefully) and externally administered testosterone.
904
905Site administration maintains MCT oil in a particular area and has a high likelihood of specifically increasing androgen receptor-mediated transcription events locally.
906
907Those that have administered MCT oil have experienced site growth. This may result from both the fascia stretching and the possible accelerated growth brought about by the synergy described herein.
908
909Site Enhancing Oils – A How to Guide by Big A
910
911The following protocol was developed by IFBB Pro Big A many years ago and has proven over the years to be highly successful with positive, even ecstatic feedback from more then a thousand users. In his own words what follows is the original methodology for maximizing muscle gain with Syntherol™ as related to all who dared to discover newfound muscle gain… gather around discover what has been holding you back. Big A, … Syntherol™ can be used for two purposes – to increase the size of a muscle or to shape a muscle.
912
913To increase size – using the biceps as an example:
914
915You need to apply Syntherol™ to EVERY head of the muscle, while rotating the applications daily within that muscle head. This is the only way to ensure that the added size keeps to the natural look/shape of that particular muscle.
916
917Since some bodybuilders prefer various ways of using Syntherol™, they usually tailor dosages to suit the individual.
918
919Some bodybuilders use 1ml per muscle (that is 1ml per muscle head – ie. inner head, outer head, etc). 1ml is used per day, every day, for a period of 2 weeks followed by a one week rest period. Then repeated.
920
921Other bodybuilders use 1ml per muscle 3 times a week for the first week, followed by 2ml per muscle 3 times a week the second week and 3ml per muscle 3 times a week the third week. That is followed by one or two week break, after which the usage pattern is repeated.
922
923The quickest way to increase a muscle’s appearance to maximum size is by following the regimen below:
924
9251ml per muscle head every day for 10 days
926
9272ml per muscle head every day for 10 days
928
9293ml per muscle head every day for 10 days
930
931If you would be using Syntherol™ in both biceps and triceps simultaneously, you can add up to 3 inches on your arms in those 30 days.
932
933It is EXTREMELLY IMPORTANT that you HAVE to massage SEVERELY the muscle that you just applied with Syntherol™!
934
935You have to make sure that there is not a lump forming. The muscle should always be soft. You should NEVER feel like you have a lump. It is also a good idea, to apply Syntherol™ just before going to the gym, so as soon as you get to the gym, you should be doing a couple light weight, high rep sets for that muscle, to get the blood moving. This again will minimize lump formation. Keep in mind, that as soon as lumps form because you did not massage, scar tissue will form as well as you want to avoid scar tissue at all costs!
936
937If you find that you cannot keep the lump build up away, but you are due for another application, wait until, by massaging, the lump goes away (it should not be more than a couple of days) and then resume from where you left off.
938
939If you have all the size you wish and just want to shape the muscle, as adding a peak on the biceps, then apply Syntherol™ to the spot, in the peak of the muscle, with 1ml every day or every second day until you obtain the peak that you desire.
940
941Where to apply Syntherol™:
942
943BICEPS: inner and outer head. One can feel the “split” in between the two heads of the biceps when a bicep is felt with the other hand. Apply the Syntherol™ on each side of that split. If you want to increase the length/thickness of the bicep, apply Syntherol™ more in the inner head (closer to the body). If increase of the peak is desired then apply Syntherol™ more in the outer head.
944
945TRICEPS: One does not need to apply Syntherol™ in the outer/horseshoe head, unless it is really lacking development behind the other tricep heads. Syntherol™ is applied in the middle and rear heads of the triceps. Generally, at the back of the arm, the upper portion is the rear head and the lower portion is the middle head, as the two heads overlap each other somewhat.
946
947DELTOIDS: Apply Syntherol™ straight into whatever head is lacking in size.
948
949CALVES: Natural calves, regardless of how big they are, have a “flat” look to the muscle. As such, one would want to keep that look, as it is not wanted to have the calves looking round like someone stuck an air hose in there. As such, Syntherol™ is applied in multiple applications, on the outside edges of the muscle. That will make the calf go outwards, while keeping the flat, natural look.
950
951QUADS: With muscles this large, one needs to do multiple daily applications. Where in the biceps 1ml per head per day is used to begin with, on quads it is needed to start with 1ml per site, 7 sites per quad. That is to avoid the “lumpy” look and keep the quad uniform. Again, to keep the natural look of the thigh, Syntherol™ should be applied to the “peak” of the outer quad, along the crest. If the teardrop is lacking, then Syntherol™ should be applied straight into it, rotating sites daily.
952
953PECS: Again, these are very large, “flat” looking muscle groups, as such the entire muscle has to be covered evenly with Syntherol™, so 3 rows of 3 applications per day per pectoral should be used. Dosage would be 0.5ml per day per application site for 10 days, followed by 1ml per day per application site for 10 days and finished off with 1.5ml per day per application site for 10 days.
954
955We strongly recommend that Syntherol™ users obtain some anatomy charts and study the muscles and the nerves that are in the area that Syntherol™ is to be applied.
956
957How does Syntherol™ work?
958
959To begin with, Syntherol™ does not stay in the muscle for 3 to 5 years as wrongly assumed. Syntherol™ gets dissipated gradually within months. However, during this time, Syntherol™ will stretch the fascia of that muscle. The fascia is a great constrictive factor in muscle growth. The more stretched the fascia is the more the muscle will grow and the more it will have that “popping” look. Syntherol™ stays in there long enough for the fascia to stretch.
960
961As the oil starts to dissipate, the “space” left by Syntherol™ is replaced with new muscle tissue growth, if the user is in a proper anabolic environment. That is an environment conducive to muscle growth, ie. resistance training, proper nutrition, recovery and supplementation. The new muscle tissue growth in the space left by Syntherol™ is the reason that when x-rays where performed on some of the people that have 25+ inch arms, there was no Syntherol™ found to be present. Syntherol™ dissipated and it was replaced by real muscle.
962
963Pain – obviously, any fascial stretching will hurt. The pain will minimise the more Syntherol™ is applied, until it will not hurt any more at all.
964
965All SEOs hurt, Syntherol™ has been reported to hurt the less due to its high level of refinement, as such making for a very thin oil.
966
967And again, we strongly suggest that the muscle be stretched and vigorously massaged throughout the day after every application with Syntherol™.
968Basic Peptide Primer
969
970What is a peptide?
971
972Peptides (proteins) are present in every living cell and possess a variety of biochemical activities. Some peptides are synthesized in the ribosomes of a cell by translation of mRNA (messenger RNA) into hormones and signaling molecules for example. Other peptides are assembled (rather then synthesized) and become enzymes with a vast variety of functions. Peptides also make up the structure of receptors which await binding of hormones & signaling molecules.
973
974A peptide is a molecule created by joining two or more amino acids. In general if the number of amino acids is less than fifty, these molecules are called peptides, while larger sequences are referred to as proteins.
975
976So peptides can be thought of as tiny proteins. They are merely strings of amino acids.
977
978Raw Constituents of Peptides (Amino Acids)
979
980Amino acids are small molecules made up of atoms. As part of their structure they posses a grouping of a Nitrogen (N) atom bonded to two Hydrogen (H) atoms. This is called an amino group and written as (NH2). In addition their structure is also made up of a second grouping of a Carbon (C) atom bonded to two Oxygen (O) and one Hydrogen atom. This group is called a carboxyl group and is written as (COOH).
981
982Between these two groupings are atoms and bonds unique to each amino acid. In other words all amino acids possess the two groupings (amino& carboxyl) as end-points between which are sandwiched a unique set of atoms.
983
984Amino Acids
985
986Inside the human body there are twenty standard amino acids used by cells in peptide biosynthesis (i.e. the cellular creation of peptides from amino acids). Our genetic code specifies how to synthesize peptides and proteins from these amino acids.
987
988Amino acids are classified into two groups: essential amino acids and nonessential amino acids.
989
990An essential amino acid is an indispensable amino acid which cannot be made by the body and must be supplied by food. These include isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Another amino acid - histidine is considered semi-essential because the body does not always require dietary sources of it.
991
992Nonessential amino acids are made by the body from the essential amino acids or the routine breakdown of proteins. The nonessential amino acids are arginine, alanine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, proline, serine, and tyrosine.
993
994All twenty amino acids are equally important in maintaining a healthy body. They are the raw constituents of peptides and proteins.
995
996The standard abbreviations for amino acids come in two forms: a one letter form and a three letter form. They are:
997
998A - Ala - Alanine C - Cys - Cysteine D - Asp - Aspartic Acid E - Glu - Glutamic Acid F - Phe - Phenylalanine G - Gly - Glycine H - His - Histidine I - Ile - Isoleucine K - Lys - Lysine L - Leu - Leucine M - Met - Methionine N - Asn - Asparagine P - Pro - Proline Q - Gln - glutamine R - Arg - Arginine S - Ser - Serine T - Thr - Threonine V - Val - Valine W - Trp - Tryptophan Y - Tyr - Tyrosine
999
1000Amino acids exist in either D (dextro) or L (levo) form. Most of the amino acids found in nature (and all within human cells) are of the L-form. As a generality all amino acids except glycine have a mirror image of the L-form. This mirror image is called the D-form. It is common when referring to the L-form (naturally occurring form) to leave off the "L" designation whereas the "D" designation is always explicitly written.
1001
1002D-amino acids are found naturally in bacterial cell walls and used in some synthetic peptides to make a peptide more stable or more resistant to degradation.
1003
1004Amino Acid + Amino Acid = Peptide
1005
1006The amino acids are joined together by what is known as a "peptide bond". A "peptide bond" is a linkage in which the nitrogen atom of one amino acid (from the amino group (NH2) binds to the carbon atom of another amino acid's carboxyl group (COOH).
1007
1008During this binding process a molecule of water is released. This is called a condensation reaction.
1009
1010The resulting CO-NH bond is called a peptide bond, and the resulting molecule is called an amide.
1011
1012On the following image note that the COOH group gives up an Oxygen Hydrogen (OH) bond and the NH2 group gives up a Hydrogen (H). This forms H2O, which is a water molecule which is not part of the newly created peptide. NOTE: in the following image the C (carbon) symbol is missing as it is assumed so I indicate it with a blue square.
1013
1014This reaction creating a peptide bond between two amino acids creates a peptide. We can call this peptide (made up of two amino acids) a dipeptide.
1015
1016This process can be repeated using the twenty amino acids as raw material to create longer peptide chains. Sometimes peptide chains consisting of fifty to 100 amino acids are called polypeptides. Often a peptide chain beyond 100 amino acids is called a protein.
1017
1018GHRP-6 is a peptide made up of just six amino acids. It's structure is often written as His-DTrp-Ala-Trp-DPhe-Lys-NH2
1019
1020Note that the Carboxyl grouping (COOH) is assumed in the first position and is usually not written. The amino group (NH2) is wrtitten in the last position. The "meat" or the part that makes GHRP-6 distinct is the seqence in the middle of histadine bonded to the "D" form of Tryptophan bonded to Alanine bonded to Tryptophan bonded to the "D" form of Phenylalanine bonded to Lysine.
1021
1022Pepdide bonds are formed by water (H2O) condensation (removing water). The converse is also true. A peptide bond can be broken down by hydrolysis (adding water).
1023
1024The Amino Acid Structures of Peptides discussed in this thread
1025
1026Growth Hormone Releasing peptides (GHRPs) (GH pulse initiators):
1027
1028    GHRP-6 (His-DTrp-Ala-Trp-DPhe-Lys-NH2)
1029
1030    GHRP-2 (DAla-D-2-Nal-Ala-Trp-DPhe-Lys-NH2)
1031
1032    Hexarelin (His-D-2-methyl-Trp-Ala-Trp-DPhe-Lys-NH2)
1033
1034    Ipamorelin (Aib-His-D-2-Nal-DPhe-Lys-NH2) - Ref-1 NOTES: Aib = Aminoisobutyryc acid D-2-Nal = "D" form of 2’-naphthylalanine
1035
1036Growth Hormone Releasing Hormone (GHRH) (amplifies the GHRP initiated pulse):
1037
1038    Growth Hormone Releasing Hormone (GHRH) aka GRF(1-44) (Tyr-Ala-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys-Val-Leu-Gly-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Met-Ser-Arg-Gln-Gln-Gly-Glu-Ser-Asn-Gln-Glu-Arg-Gly-Ala-Arg-Ala-Arg-Leu-NH2) = half-life "less then 10 minutes", perhaps as low as 5 minutes. - Ref-2
1039
1040    GRF(1-29) aka Sermorelin (Tyr-Ala-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys-Val-Leu-Gly-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Met-Ser-Arg-NH2) - the biologically active portion of the 44 amino acid GHRH = half-life "less then 10 minutes", perhaps as low as 5 minutes. - Ref-3
1041
1042    Longer-lasting analogs of GRF(1-29): -- replace the 2nd amino acid Alanine w/ D-Alanine only to modify GRF(1-29), D-Ala2 GRF(1-29) (Tyr-DAla-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys-Val-Leu-Gly-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Met-Ser-Arg-NH2) =half-life "closer to 10 minutes" - Ref-4
1043
1044-- replace the 2nd, 8th, 15th & 27th amino acids & get modified GRF(1-29) or CJC-1295 w/o the DAC (i.e. the part that will bind to albumin & make the half-life days) (Tyr-DAla-Asp-Ala-Ile-Phe-Thr-Gln-Ser-Tyr-Arg-Lys-Val-Leu-Ala-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Leu-Ser-Arg-NH2) = Half-life at least 30 minutes or so - Ref-5
1045
1046-- CJC-1295 (Tyr-DAla-Asp-Ala-Ile-Phe-Thr-Gln-Ser-Tyr-Arg-Lys-Val-Leu-Ala-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Leu-Ser-Arg-Lys-(Maleimidopropionyl)-NH2) = Half-life measured in days, - Ref-6
1047
1048NOTES: Lys = linker to the Drug Affinity Complex (aka (Maleimidopropionyl))
1049
1050"Since GH is released in a pulsatile manner and a higher level of GH is observed between 15 and 30 min after subcutaneous administration of GH-RH analogues, hydrolysis by trypsin-like enzymes could not affect the result of stimulation." - Potent Trypsin-resistant hGH-RH Analogues, JAN IZDEBSKI, J. Peptide Sci. 10: 524–529 (2004)
1051
1052The analog in the above quoted study resisted degradation for 30 minutes. The quote implies that if your analog can last 30 minutes it has tapped out the potential for a single pulse.
1053
1054Since another pulse won't be generated for about 2.5 - 3 hours analogs that last more than 30 minutes up to 3 hours are not any more beneficial.
1055
1056You would need an analog that kept growth hormone releasing hormone around beyond 3 hours to have it trigger a second pulse.
1057
1058Otherwise dosing the 30 minute analog every 3 hours will maximize GH output OR you could just use an analog such as CJC-1295 which lasts for many days and will trigger several GH pulses a day for several days on a single dose.
1059
1060References:
1061
1062Ref-1 - "lack of effect on ACTH and cortisol plasma levels" - Ipamorelin, the first selective growth hormone secretagogue , K Raun, European Journal of Endocrinology, 1996 Vol 139, Issue 5, 552-561
1063
1064Ref-2 - Rapid enzymatic degradation of growth hormone-releasing hormone by plasma in vitro and in vivo to a biologically inactive product cleaved at the NH2 terminus, Frohman LA, J Clin Invest. 1986 78:906–913 andIncorporation of D-Ala2 in Growth Hormone-Releasing Hormone-( l-29)-NH2 Increases the Half-Life and Decreases Metabolic Clearance in Normal Men, STEVEN SOULE, Journal of Clinical Endocrinology and Metabolism 1994 Vol. 79, No. 4
1065
1066Ref-3 - Rapid enzymatic degradation of growth hormone-releasing hormone by plasma in vitro and in vivo to a biologically inactive product cleaved at the NH2 terminus, Frohman LA, J Clin Invest. 1986 78:906–913 andIncorporation of D-Ala2 in Growth Hormone-Releasing Hormone-( l-29)-NH2 Increases the Half-Life and Decreases Metabolic Clearance in Normal Men, STEVEN SOULE, Journal of Clinical Endocrinology and Metabolism 1994 Vol. 79, No. 4
1067
1068Ref-4 - Incorporation of D-Ala2 in Growth Hormone-Releasing Hormone-( l-29)-NH2 Increases the Half-Life and Decreases Metabolic Clearance in Normal Men, STEVEN SOULE, Journal of Clinical Endocrinology and Metabolism 1994 Vol. 79, No. 4
1069What is growth hormone?
1070
1071Synthetic Growth Hormone is an artificially created hormone "identical" to the major naturally produced (endogenous) isoform. It is often referred to by its molecular mass which is 22kDa (kilodaltons) and is made up of a sequence of 191 amino acids (primary structure) with a very specific folding pattern that comprise a three-dimensional structure (tertiary structure). This tertiary structure is subject to potential shape change through a process known as thermal denaturation. While many labs are capable of generating growth hormone (GH) with the proper primary structure not all will be capable of creating a tertiary structure identical to the major naturally occurring growth hormone. The tertiary structure can determine the strength with which the growth hormone molecule binds to a receptor which will in turn affect the "strength" of the intracellular signaling which mediates the events leading to protein transcription, metabolism, IGF-1 creation, etc. It is this inconsistency that accounts in part for the differences in effectiveness of various non-pharmaceutically produced synthetic growth hormone.
1072
1073Naturally produced Growth Hormone is produced in the anterior pituitary and to a far lesser extent in peripheral tissue. It is made up of a blend of isoforms the majority of which is the 22kDa (191 amino acid) variety with which most are familiar. In addition an isoform that is missing the 15 amino acids that interact with the prolactin receptor is also produced. This form is known as 20kDa and although it binds differently to the growth hormone receptor it has been shown to be equally potent to 22kDa. It appears that 20kDa has lower diabetogenic activity then 22kDa. The pituitary releases a blend of these two isoforms with 20kDa averaging perhaps 10% of the total although this percentage increases post-exercise. Currently there is no synthetic produced for external administration for this isoform.
1074
1075Growth hormone (GH) in the body is released in pulsatile fashion. It has been demonstrated that this pattern promotes growth. The pituitary is capable of rather quickly synthesizing very large amounts of growth hormone which it stores large amounts in both a finished and unfinished form. Adults rarely experience GH pulses (i.e. releases of pituitary stores) that completely deplete these stores. As we age we do not lose the ability to create and store large amounts of growth hormone. Rather we experience a diminished capacity to "instruct" their release. The volume of GH that is released can not be properly equated to the exogenous administration of synthetic GH for the reason that a set of behavioral characteristics accompany natural GH that differ from those of synthetic GH. Among those characteristics are concentrated pulsatile release which upon binding in mass to growth hormone receptors on the surface of cells initiate signaling cascades which mediate growth events by translocating signaling proteins to the nucleus of the cell where protein transcription and metabolic events occur.
1076
1077These very important signaling pathways desensitize to Growth Hormone's initiating effects and need to experience an absence of Growth Hormone in order to reset and be ready to act again. The presence of GH released in pulsatile fashion is graphed as a wave with the low or no growth hormone period graphed as a trough. Therefore attempting to find a natural GH to synthetic GH equivalency is not very productive because in the end what is probably import is:
1078
1079    the quantity & quality of intracellular signaling events; and
1080    the degree to which GH stimulates autocrine/paracrine (locally produced/locally used) muscle IGF-1 & post-exercise its splice variant MGF.
1081
1082Synthetic GH versus Natural GH in IUs
1083
1084An attempt has been made on my part and can be found at:
1085
1086Growth Hormone Administration vs. CJC-1295/GHRP-6 + GHRH (part I of II)
1087
1088Growth Hormone Administration vs. CJC-1295/GHRP-6 + GHRH (part II of II) Rather than demonstrate absolute values this comparison articles should serve to demonstrate that the body can produce pharmacological levels of growth hormone.
1089
1090Brief overview of natural GH release
1091
1092The initiation of growth hormone release in the pituitary is dependent on a trilogy of hormones:
1093
1094Somatostatin which is the inhibitory hormone and responsible in large part for the creation of pulsation;
1095
1096Growth Hormone Releasing Hormone (GHRH) which is the stimulatory hormone responsible for initiating GH release; and
1097
1098Ghrelin which is a modulating hormone and in essence optimizes the balance between the "on" hormone & the "off" hormone. Before Ghrelin was discovered the synthetic growth hormone releasing peptides (GHRPs) were created and are superior to Ghrelin in that they do not share Ghrelin's lipogenic behavior. These GHRPs are GHRP-6, GHRP-2, Hexarelin and later Ipamorelin all of which behave in similar fashion. In the aging adult these Ghrelin-mimetics or the GHRPs restore a more youthful ability to release GH from the pituitary as they turn down somatostatin's negative influence which becomes stronger as we age and turn up growth hormone releasing hormone's influence which becomes weaker as we age.
1099
1100The exogenous administration of Growth Hormone Releasing Hormone (GHRH) creates a pulse of GH release which will be small if administered during a natural GH trough and higher if administered during a rising natural GH wave.
1101
1102Growth Hormone Releasing Peptides (GHRP-6, GHRP-2, Hexarelin) are capable of creating a larger pulse of GH on their own then GHRH and they do this with much more consistency and predictability without regard to whether a natural wave or trough of GH is currently taking place.
1103
1104Synergy of GHRH + GHRP
1105
1106It is well documented and established that the concurrent administration of Growth Hormone Releasing Hormone (GHRH) and a Growth Hormone Releasing Peptide (GHRP-6, GHRP-2 or Hexarelin) results in synergistic release of GH from pituitary stores. In other words if GHRH contributes a GH amount quantified as the number 2 and GHRPs contributed a GH amount quantified as the number 4 the total GH release is not additive (i.e. 2 + 4 = 6). Rather the whole is greater than the sum of the parts such that 2 + 4 = 10.
1107
1108While the GHRPs (GHRP-6, GHRP-2 and Hexarelin) come in only one half-life form and are capable of generating a GH pulse that lasts a couple of hours re-administration of a GHRP is required to effect additional pulses.
1109
1110Growth Hormone Releasing Hormone (GHRH) however is currently available in several forms which vary only by their half-lives. Naturally occurring GHRH is either a 40 or 44 amino acid peptide with the bioactive portion residing in the first 29 amino acids. This shortened peptide identical in behavior and half-life to that of GHRH is called Growth Hormone Releasing Factor and is abbreviated as GRF(1-29).
1111
1112GRF(1-29) is produced and sold as a drug called Sermorelin. It has a short-half life measured in minutes. If you prefer analogies think of this as a Testosterone Suspension (i.e. unestered).
1113
1114To increase the stability and half-life of GRF(1-29) four amino acid changes where made to its structure. These changes increase the half-life beyond 30 minutes which is more than sufficient to exert a sustained effect which will maximize a GH pulse. This form is often calledtetrasubstituted GRF(1-29) (or modified) and unfortunately & confusingly mislabeled as CJC-1295. If you prefer analogies think of this as a Testosterone Propionate (i.e. short-estered).
1115
1116Note that some may also refer to this as CJC-1295 without the DAC (Drug Affinity Complex).
1117
1118Frequent dosing of either the aforementioned modified GRF(1-29) or regular GRF(1-29) is required and as previously indicated works synergistically with a GHRP.
1119
1120In an attempt to create a more convenient long-lasting GHRH, a compound known as CJC-1295 was created. This compound is identical to the aforementioned modified GRF(1-29) with the addition of the amino acid Lysine which links to a non-peptide molecule known as a "Drug Affinity Complex (DAC)". This complex allows GRF(1-29) to bind to albumin post-injection in plasma and extends its half-life to that of days. If you prefer analogies think of this as a Testosterone Cypionate (i.e. long-estered). However this is not accurate. CJC-1295 results in continual GH bleed. Although natural pulsation still occurs CJC-1295 does nothing to increase those pulses. Instead it raises base levels of GH and creates a more feminized pattern of release. This not desirable.
1121
1122Modified GRF(1-29)however when combined with a GHRP brings about a substantial pulse which has desirable effects.
1123A Brief Summary of Dosing and Administration
1124
1125Dosing GHRPs
1126
1127The saturation dose in most studies on the GHRPs (GHRP-6, GHRP-2, Ipamorelin & Hexarelin) is defined as either 100mcg or 1mcg/kg.
1128
1129What that means is that 100mcg will saturate the receptors fully, but if you add another 100mcg to that dose only 50% of that portion will be effective. If you add an additional 100mcg to that dose only about 25% will be effective. Perhaps a final 100mcg might add a little something to GH release but that is it.
1130
1131So 100mcg is the saturation dose and you could add more up to 300 to 400mcg and get a little more effect.
1132
1133A 500mcg dose will not be more effective then a 400mcg, perhaps not even more effective then 300mcg.
1134
1135The additional problems are desensitization & cortisol/prolactin side-effects.
1136
1137Ipamorelin is about as efficacious as GHRP-6 in causing GH release but even at higher dose (above 100mcg) it does not create prolactin or cortisol.
1138
1139GHRP-6 at the saturation dose 100mcg does not really increase prolactin & cortisol but may do so slightly at higher doses. This rise is still within the normal range.
1140
1141GHRP-2 is a little more efficacious then GHRP-6 at causing GH release but at the saturation dose or higher may produce a slight to moderate increase in prolactin & cortisol. This rise is still within the normal range although doses of 200 - 400mcg might make it the high end of the normal range.
1142
1143Hexarelin is the most efficacious of all of the GHRPs at causing an increase in GH release. However it has the highest potential to also increase cortisol & prolactin. This rise will occur even at the 100mcg saturation dose. This rise will reach the higher levels of what is defined as normal.
1144
1145Desensitization
1146
1147GHRP-6 can be used at saturation dose (100mcg) three or four times a day without risk of desensitization.
1148
1149GHRP-2 probably at saturation dose several times a day will not result in desensitization.
1150
1151Hexarelin has been shown to bring about desensitization but in a long-term study the pituitary recovered its sensitivity so that there was not long-term loss of sensitivity at saturation dose. However dosing Hexarelin even at 100mcg three times a day will likely lead to some down regulation within 14 days.
1152
1153If desensitization were to ever occur for any of these GHRPs simply stopping use for several days will remedy this effect.
1154
1155Chronic use of GHRP-6 at 100mcg dosed several times a day every day will not cause pituitary problems, nor significant prolactin or cortisol problems, nor desensitize.
1156
1157GHRH
1158
1159Now Sermorelin, GHRH (1-44) and GRF(1-29) all are basically GHRH and have a short half-life in plasma because of quick cleavage between the 2nd & 3rd amino acid. This is no worry naturally because this hormone is secreted from the hypothalamus and travels a short distance to the underlying anterior pituitary and is not really subject to enzymatic cleavage. The release from the hypothalamus and binding to somatotrophs (pituitary cells) happens quickly.
1160
1161However when injected into the body it must circulate before finding its way to the pituitary and so within 3 minutes it is already being degraded.
1162
1163That is why GHRH in the above forms must be dosed high to get an effect.
1164
1165GHRH analogs
1166
1167All GHRH analogs swap Alanine at the 2nd position for D-Alanine which makes the peptide resistant to quick cleavage at that position. This means analogs will be more effective when injected at smaller dosing.
1168
1169The analog tetra or 4 substituted GRF(1-29) sometimes called CJC w/o the DAC or referred to by me as modified GRF(1-29) has other amino acid modifications. They are a glutamine (Gln or Q) at the 8-position, alanine (Ala or A) at the 15-position, and a leucine (Leu or L) at the 27-position.
1170
1171The alanine at the 8th position enhances bioavailability but the other two amino substitutions are made to enhance the manufacturing process (i.e. create manufacturing stability).
1172
1173For use in vivo, in humans, the GHRH analog known as CJC w/o the DAC or tetra (4) substituted GRF(1-29) or modified GRF(1-29) is a very effective peptide with a half-life probably 30+ minutes.
1174
1175That is long enough to be completely effective.
1176
1177The saturation dose is also defined as 100mcg.
1178
1179Problem w/ Using any GHRH alone
1180
1181The problem with using a GHRH even the stronger analogs is that they are only highly effective when somatostatin is low (the GH inhibiting hormone). So if you unluckily administer in a trough (or when a GH pulse is not naturally occurring) you will add very little GH release. If however you luckily administer during a rising wave or GH pulse (somatostatin will not be active at this point) you will add to GH release.
1182
1183Solution is GHRP + GHRH analog
1184
1185The solution is simple and highly effective. You administer a GHRH analog with a GHRP. The GHRP creates a pulse of GH. It does this through several mechanisms. One mechanism is the reduction of somatostatin release from the hypothalamus, another is a reduction of somatostatin influence at the pituitary, still another is increased release of GHRH from the brain and finally GHRPs act on the same pituitary cells (somatotrophs) as do GHRHs but use a different mechanism to increase cAMP formation which will further cause GH release from somatotroph stores.
1186
1187GHRH also has a way of reciprocally reinforcing GHRPs action.
1188
1189The result is a synergistic GH release.
1190
1191The GH is not additive it is synergistic. By that I mean:
1192
1193If GHRH by itself will cause a GH release valued at 2 and GHRP itself will cause a GH release valued at 5
1194
1195Together the GH is not 7 (5+2) it turns out to say 16!
1196
1197A solid protocol
1198
1199A solid protocol would be to use a GHRP + a GHRH analog pre-bed (to support the nightime pulse) and once or twice throughout the day.
1200
1201For anti-aging, deep restful restorative sleep, the once at night dosing is all you need. For an adult aged 40+ it is enough to restore GH to youthful levels.
1202
1203However for bodybuilding or fatloss or injury repair multiple dosings can be effective.
1204
1205The GHRH analog can be used at 100mcg and as high as you want without problems.
1206
1207The GHRP-6 can always be used at 100mcg w/o problems but a dose of 200mcg will probably be fine as well.
1208
1209Again desensitization is something to keep an eye on particularly with the highest doses of GHRP-2 and all doses of Hexarelin.
1210
1211So 100 - 200mcg of GHRP-6 + 100 - 500mcg+ of a GHRH analog taken together will be effective. This may be dosed several times a day to be highly effective.
1212
1213A solid approach is a bit more conservative at 100mcg of GHRP-6 + 100mcg of a GHRH analog dosed either once, twice, three or four times a day. When dosing multiple times a day at least 3 hours should separate the administrations.
1214
1215The difference is once a day dosing pre-bed will give a youthful restorative amount of GH while multiple dosing and or higher levels will give higher GH & IGF-1 levels when coupled with diet & exercise will lead to muscle gain & fatloss.
1216
1217Dose w/o food
1218
1219Administration should ideally be done on either an empty stomach or with only protein in the stomach. Fats & carbs blunt GH release. So administer the peptides and wait about 20 minutes (no more then 30 but no less then 15 minutes) to eat. AT that point the GH pulse has about hit the peak and you can eat what you want.
1220Basic Guide: CJC-1295
1221
1222Partial explanation (Oct 21, 2009) "Cell-to-cell communication is also likely to reflect the density and proximity of adjacent cells as GH responsiveness (but not sensitivity) to GHRH is enhanced at higher densities and basal GH release is greatest at low densities."
1223
1224"Cell-to-cell contact may therefore affect the cellular integrity of somatotrophs because GH synthesis or secretory granule storage may be better maintained in high density cell concentration then in low-density concentrations." - Growth Hormone, Stephen Harvey What happens is cells in the pituitary communicate. They self organize and create a firing network for coordinated growth hormone release. This communication creates a high density of GH releasing cells. They are in close proximity through their communicatory network. The cells have specific spatial relationships that may be modulated by peripheral endocrines. These include sex steroids, thyroid hormones, glucorticoids and even the pancreatic and gut hormones. Their spatial relationship is also effected by physiological state such as nutrient status, age and pregnancy.
1225
1226As a quick example, corticotroph, thyrotrophs and folliculostellate cells are in close proximity to somatotrophs and communicate with them through gap junctions (almost like just reaching out and touching signaling). They have the potential to effect and be effected by their neighbors.
1227
1228What happens when you have GHRH always around is you force these somatotrophs to release GH because they are sensitive to the GHRH binding to them and effecting release. By constantly occupying you are preventing them from coordinating with surrounding cell populations. You force these cells to act as low density subpopulations. Basal GH release is greatest when you can disperse the spatial relationship between somatotrophs and that is what an always on GHRH will do.
1229
1230CJC-1295 as an always on GHRH will force upon somatotrophs loner behavior with a single constant chore. This reduces GH responsiveness as this only occurs when somatotrophs can communicate, self organize and maintain social relationships with the surrounding community. These types of social somatotrophs are better able to make and store GH then the loner cells.
1231
1232So CJC-1295 seems to disperse somatotrophs and enslave them getting less from them then if it had just let them congregate in towns and cities.
1233
1234Aging has an effect on the vitality of city centers as well and as we age these somatotroph population centers become less vigorous. By using a more physiological GHRH such as modified GRF(1-29) together with a modulator GHRP-2 we revitalize that inner city and allow our cells to be more social and thus more productive. If instead we choose to use CJC-1295 we not only fail to remedy the problem associated with age , but we may end up exacerbating it.
1235
1236I conjecture that it also makes them better neighbors to corticotroph, thyrotrophs and folliculostellate cells as well.
1237
1238Revision 2 [8/31/08]
1239
1240Restoring Growth Hormone "It has been argued that the age-dependent decline in sex steroid, Growth Hormone, and IGF-I production is nature’s way of protecting us from cancer and heart disease, but a far more likely scenario is that once we reach our reproductive capacity, nature begins programming us for death."- Roy G. Smith, Ph.D. Director, Huffington Center on Aging; Professor, Department of Molecular & Cellular Biology; former Vice President for Basic Research at Merck Research Laboratories, Merck & Co Such programming begins as the second decade of life draws to a close, the negative consequences of which become more noticeable with each passing year.
1241
1242We begin to experience a steady decline in immune function. (1,2) Our bodies increase production of glucocorticoids (catabolic hormones) and cytokines (inflammatory) which negatively impact metabolism, bone density, strength, exercise tolerance, cognitive function, and mood. (3,4–8)
1243
1244The hormones of sex, dehydroepiandrosterone (DHEA), Growth Hormone (GH), and Insulin-like Growth Factor (IGF-1) are positively correlated with the health and well-being of the body in general and the specific functioning of metabolism, the cardiovascular system, the musculature skeletal system, cognitive function & the immune system. However these hormonal levels naturally decline as we age and as a consequence those systems necessary to maintain optimal health decline as well. (1-4,9)
1245
1246"Hence, if we wish to maintain quality of life during aging we must oppose nature." - Roy G. Smith, Ph.D.
1247
1248A progressive decline in lean body mass, atrophy of its component organs & reduction in their function and increased deposition of adipose tissue mass characteristic of the aging human body result partially from the body's diminished secretion of growth hormone. (10-13) These negative changes resulting from growth hormone deficiency have been shown to be reversible by replacement doses of growth hormone. (14-21)
1249
1250Growth Hormone is a vital anabolic hormone whose positive stimulatory effects on protein synthesis (particularly in the liver, muscle, bone, cartlidge, spleen, kidney, skin, thymus, and red blood cells) and on lipolysis (the breakdown of fat stored in fat cells) contributes greatly to growth, repair & well-being. (10)
1251
1252Growth Hormone (GH) secretion is primarily regulated by the release of two peptides, Growth Hormone-Releasing Hormone (GHRH) andSomatostatin. The hypothalamus region of the brain releases these hormones in response to signals from the central nervous system. GHRH once released makes its way to the receptors on the somatotrope cells of the pituitary gland below the brain where it stimulates Growth Hormone release.
1253
1254Somatostatin once released makes its way to the receptors on the somatotrope cells of the pituitary gland below the brain where it inhibitsGrowth Hormone release. (15)
1255
1256The primary physiological action of somatostatin is to inhibit synthesis and release of GH. (16-19) The primary physiological action of Growth Hormone-Releasing Hormone (GHRH) is to stimulate synthesis and release of GH.
1257
1258The end product of this cascade, Growth Hormone (GH) once secreted exerts its effect in the body as a whole both directly and indirectly through its initiation of Insulin-like Growth Factor (IGF-1) synthesis in the liver. IGF-1 in turn exerts its effect in the body and its rise in turn begins to inhibit any further GH release.
1259
1260Growth Hormone (GH) is released periodically within the body in a controlled pulsating fashion. This periodic pattern plays an important role in transmitting the GH "growth, repair & well-being" message to tissue. A review of several studies involving GH replacement in GH-deficient animals reveals the biological significance of episodic secretion. These studies conclude that GH released in a pulsatile pattern is far more efficient in improving mammalian growth and repair than the method of GH administration by constant infusion.
1261
1262In males GH pulses occur approximately every three (3) hours, a frequency that appears across most mammals. The secretion bursts are preceded and followed by almost undetectable levels of plasma GH.
1263
1264In females however GH pulses occur more frequently and the base level of plasma GH remains higher than males who have fewer GH pulses but the amplitude of which are more pronounced.
1265
1266GH pulse amplitudes are increased during slow wave sleep such that particularly in males, most GH secretion occurs at night. (22)
1267
1268Growth Hormone secretion is highest during the growing years of youth and early adulthood. In humans the secretion rate starts to noticeably decrease during the third decade of life and strongly decreases during the fourth decade of life. As we age the daytime secretory pulses diminish first, while the sleep associated GH pulse persists and diminishes gradually.
1269
1270Nudging Nature
1271
1272Growth Hormone levels may be increased either by exogenically administering Growth Hormone or by administering Growth Hormone-Releasing Hormone which then endogenically stimulates the somatrope cells of the pituitary to secrete additional Growth Hormone. The primary advantage of GHRH is that GH ends up being released in physiological conformance to the body’s natural biorhythm. This biorhythm is pulsatile.
1273
1274Studies have concluded that endogenous Growth Hormone Releasing Hormone (GHRH) is the principal regulator of pulsatile GH secretion in humans and that continuous GHRH infusion augments pulsatile GH release. Whereas exogenic administration of GH raises overall GH levels but has no effect on amplifying the pulses.
1275
1276People of all ages naturally continue to possess the ability to secrete GH from stores within the pituitary. Most studies are in agreement on this point. One study in particular examined the effects of administration of GHRH & a Growth Hormone Releasing Peptide on all adult age groups from those in their 20's to those above 75 years of age. They observed substantial increases in GH release as a direct result of administration of GHRH & GHRP-6. This prompted them to conclude, "...that the lack of side-effects & safety of the protocol and the discovered lack of age-related decline in the 'GHRH-GHRP-6-mediated' GH release opens the possibility of using it as a therapeutical tool to revert some deleterious manifestations of aging in man." (23)
1277
1278Long-lasting GHRH analog CJC-1295
1279
1280While the studies have demonstrated repeatedly that administration of GHRH does increase GH secretion and amplifies the release pulse there does remain a significant drawback. GHRH has a very short half life, measured in minutes with a fairly short clearance rate measured in hours. (24) While this is a sufficient amount of time to exert a positive effect on GH secretion, particularly if GHRH is administered multiple times a day, the result is less than optimal. (25,26)
1281
1282It is for this reason that longer-lasting analogs of GHRH were researched and developed. (28) The most effective of which is CJC-1295.
1283
1284Exposure of native GHRH to blood plasma results in rapid degradation. CJC-1295, a synthetic human GHRH analog avoids rapid degradation by possessing the ability to selectively and covalently bind to endogenous albumin after subcutaneous administration. Albumin possesses a half-life of 19 days in humans and so modified GHRH bound to albumin greatly extends its half-life and duration of action. (27)
1285
1286In a recent (2006) study "Prolonged Stimulation of Growth Hormone (GH) and Insulin-Like Growth Factor I Secretion by CJC-1295, a Long-Acting Analog of GH-Releasing Hormone, in Healthy Adults", Sam L. Teichman, et al. Journal of Clinical Endocrinology & Metabolism 91(3):799-805, CJC-1295 was found to result in "sustained, dose-dependent increases in GH and IGF-I levels in healthy adults and was safe and relatively well tolerated, particularly at doses of 30mcg/kg or 60 mcg/kg."
1287
1288It has been demonstrated repeatedly in various studies that GHRH is effective at instigating GH release and longer acting analogs do increase the overall effectiveness. So it is no surprise that the results of this CJC-1295 study comport with what has been previously demonstrated.
1289
1290What was unknown was what effect persistent elevation of GH by a long-lasting GHRH analog would have on the pulsatility of release. This was explored in a follow up study, "Pulsatile Secretion of Growth Hormone (GH) Persists during Continuous Stimulation by CJC-1295, a Long- Acting GH-Releasing Hormone Analog", Madalina Ionescu, et al. The Journal of Clinical Endocrinology & Metabolism 91(12):4792-4797.
1291
1292That study found that pulsatility was not interfered with and was in fact preserved in all subjects both immediately after administration and continuing 7 days post-administration.
1293
1294This is obviously a very beneficial characteristic to preserve. In fact episodic release appears to be imperative to growth and repair of tissue in mammals.
1295
1296The study further found that while growth hormone secretion was increased by almost fifty percent there was no increase in pulse amplitude or frequency. All of the increase came from a substantial elevation of trough levels with preserved pulsatility.
1297
1298One further note of interest is that study participants were all of young age with lower lean body masses which may indicate that GHRH in the form of CJC-1295 is an effective avenue for growth hormone release for those of young age.
1299
1300The results of the study charted above show that administration of single doses of CJC-1295 remained in high concentration for 7 days with measurable concentration for 14 subsequent days. (29)
1301
1302As seen in the chart below this resulted in substantial increases in mean serum GH levels in all dosing groups, which were dose incremental and persisted for up to 7 days.
1303
1304As seen in the chart below this chronic elevation in CJC-1295 levels resulted in substantial increases in mean serum IGF-1 levels in all dosing groups, which were dose incremental and persisted for up to 7 days.
1305
1306The results from a toxicology study wherein 50mcg/kg of CJC-1295 was administered subcutaneously to monkeys for a period of six months found no ill effects and no indication of presence of neutralizing antibodies. They concluded that the Drug Affinity Complex (DAC) a technology that enables covalent binding (conjugation) of a drug to albumin produced no evidence of immunogenic or immunotoxic effects in monkeys. (30)
1307
1308In summary, although the added Drug Affinity Complex adds complexity and increases the expense of CJC-1295 peptide synthesis, it does add tremendously to both the dosing convenience and the biological activity of GHRH without any identifiable adverse toxicity.
1309
1310References:
1311
13121 - Hadden JW, Malec PH, Coto J, Hadden EM 1992 Thymic involution in aging. Prospects for correction. Ann NY Acad Sci 673: 231–239
1313
13142 - Mackall CL, Gress RE 1997 Thymic aging and T-cell regeneration. Immunol Rev 160:91–102
1315
13163 - Ershler WB, Keller ET 2000 Age-associated increased interleukin-6 gene expression, late-life diseases, and frailty. Annu Rev Med 51:245–270
1317
13184 - van Eekelen JA, Rots NY, Sutanto W, de Kloet ER 1992 The effect of aging on stress responsiveness and central corticosteroid receptors in the brown Norway rat. Neurobiol Aging 13:159–170
1319
13205 - Martignoni E, Costa A, Sinforiani E, Liuzzi A, Chiodini P, MauriM, Bono G, Nappi G 1992 The brain as a target for adrenocorticalsteroids: cognitive implications. Psychoneuroendocrinology 17: 343–354
1321
13226 - Liu J, Mori A 1999 Stress, aging, and brain oxidative damage. Neurochem Res 24:1479–1497
1323
13247 - Sapolsky R, Armanini M, Packan D, TombaughG1987 Stress and glucocorticoids in aging. Endocrinol Metab Clin North Am 16:965– 980
1325
13268 - Heffelfinger AK, Newcomer JW 2001 Glucocorticoid effects on memory function over the human life span. Dev Psychopathol 13:491–513
1327
13289 - Murialdo G, Barreca A, Nobili F, Rollero A, Timossi G, Gianelli MV, Copello F, Rodriguez G, Polleri A 2001 Relationships between cortisol, dehydroepiandrosterone sulphate and insulin-like growth factor-I system in dementia. J Endocrinol Invest 24:139–146
1329
133010 - Rudman D. Growth hormone, body composition, and aging. J Am Geriatr Soc 1985; 33:800-7.
1331
133211 - Meites J. Neuroendocrine biomarkers of aging in the rat. Exp Gerontol 1988; 23:349-58.
1333
133412 - Finkelstein JW, Boyar RM, Roffwarg HP, Kream J, Hellman L. Age-related change in the twenty-four-hour spontaneous secretion of growth hormone. J Clin Endocrinol Metab 1972; 35:665-70.
1335
133613 - Rudman D, Kutner MH, Rogers CM, Lubin MF, Fleming GA, Bain RP. Impaired growth hormone secretion in the adult population: relation to age and adiposity. J Clin Invest 1981; 67:1361-9.
1337
133814 - van Buul-Offers S, Van den Brande JL. The growth of different organs of normal and dwarfed Snell mice, before and during growth hormone therapy. Acta Endocrinol 1981; 96:46-58.
1339
134015 - Parra A, Argote RM, Garcia G, Cervantes C, Alatorre S, Perez-Pasten E. Body composition in hypopituitary dwarfs before and during human growth hormone therapy. Metabolism 1979; 28:851-7.
1341
134216 - van der Werff ten Bosch JJ, Bot A. Effects of human pituitary growth hormone on body composition. Neth J Med 1987; 30:220-7.
1343
134417 - Crist DM, Peake GT, Mackinnon LT, Sibbitt WL Jr, Kraner JC. Exogenous growth hormone treatment alters body composition and increases natural killer cell activity in women with impaired endogenous growth hormone secretion. Metabolism 1987; 36:1115-7.
1345
134618 - Jorgensen JOL, Pedersen SA, Thuesen L, et al Beneficial effects of growth hormone treatment in GH-deficient adults. Lancet 1989; 1:1221-5.
1347
134819 - Crist DM, Peake GT, Egan PA, Waters DL. Body composition response to exogenous GH during training in highly conditioned adults. J Appl Physiol 1988; 65:579-84.
1349
135020 - Salomon F, Cuneo RC, Hesp R, Sonksen PH. The effects of treatment with recombinant human growth hormone on body composition and metabolism in adults with growth hormone deficiency. N Engl J Med 1989; 321:1797- 803.
1351
135221 - Jones AJS, O’Connor JV. Chemical characterization of methionyl human growth hormone. In: Hormone drugs: proceedings of the FDA–USP Workshop on Drug and Reference Standards for Insulins, Somatropins, and Thyroid- axis Hormones, Bethesda, Maryland, May 19–21, 1982.
1353
135422 - Holl RW, Hartman ML, Veldhuis JD, et al. Thirty-second sampling of plasma growth hormone in man: correlation with sleep stages. J Clin Endocrinol Metab 1991;72:854–61.
1355
135623 - Micic D, et al. Preserved Growth Hormone (GH) Secretion in Aged and Very Old Subjects after Testing with the Combined Stimulus GH-Releasing Hormone plus GH-Releasing Hexapeptide-6. J Clin Endocrinol Metab. 1998 Jul;83(7):2569-72
1357
135824 - Frohman LA, Downs TR, Williams TC, Heimer EP, Pan YCE, and Felix AM. Rapid enzymatic degradation of growth hormone-releasing hormone by plasma in vitro and in vivo to a biologically inactive, N-terminally cleaved product. J Clin Invest 78: 906–913, 1986.
1359
136025 - Iordanova VK, Wen SY, Moreau IA, Smith SY, Frohman LA, and Castaigne JP. Every other day subcutaneous administration of CJC-1295, a drug affinity complex (DAC)-growth hormone releasing factor (GRF) analogue, increases body weight and bone mineral content in dogs (Abstract). 87th Annual Meeting of The Endocrine Society, 2005, p. P1–78.
1361
136226 - Jette L, Leger R, Thibaudeau K, Benquet C, Robitaille M, Pellerin I, Paradis V, van Wyk P, Pham K, and Bridon DP. Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats: identification of CJC-1295 as a long-lasting GRF analog. Endocrinology 146: 3052–3058, 2005.
1363
136427 - Peters JRT. All About Albumin. Biochemistry, Genetics and Medical Applications. San Diego, CA: Academic, 1996.
1365
136628 - Hoffman, Andrew R., et al. Efficacy of a Long-Acting Growth Hormone (GH) Preparation in Patients with Adult GH Deficiency. J Clin Endocrinol Metab 90(12):6431–6440
1367
136829 - Teichman SL, Neale A, Lawrence B, Cagnon C, Castaigne JP, and Frohman LA. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab 91: 799–805, 2006.
1369
137030 – Wen, S. et al. Immunogenicity AND Immunotoxicity Assessments of Two Drug Affinity Complexe Compounds in Cynomogus Monkeys. Toxicologist, Report 170, 2005.
1371Basic Guide: Growth Hormone Secretagogues
1372
1373Growth Hormone Secretagogues
1374
1375In the 1980's three classes of compounds where studied to determine their effect on growth hormone release. These three compounds were:
1376
1377Growth Hormone Releasing Hormone (natural hormone) Growth Hormone Releasing Peptides (synthetic molecules often termed "GH-Secretagogues") Opiates (Dermorphin & Benzomorphan) Individually each class of compound when administered in laboratory rats was found to induce growth hormone release. However when they were all combined growth hormone release dramatically increased.
1378
1379Growth Hormone Releasing Hormone (GHRH) + Growth Hormone Releasing Peptide (GHRP) was found to induce a large synergistic secretion of growth hormone (GH).
1380
1381However when the Opiate was combined with GHRH & GHRP the synergy was huge amounting to a release of GH more than double that achieved by the GHRH/GHRP combo alone.
1382
1383When all three classes of compounds were examined it was discovered that each compound released GH by a mechanism different and distinct from that of the others. Furthermore it was found that these three modes of action accomplished growth hormone release in ways complementing and not interfering with each other.
1384
1385Unfortunately opiates have several drawbacks. Not withstanding their illegality chronic use is both toxic and addicting with undesirable alterations in normal physiology.
1386
1387Fortunately we are left with two tools with which we can maximize a synergistic release of growth hormone. These tools have no toxicity and promote desirable alterations in normal physiology.
1388
1389Growth Hormone Releasing Hormone (GHRH) in the form of its long-lasting analog (CJC-1295) was discussed in the previous article. It is therefore left to this article to discuss Growth Hormone Releasing Peptides (GHRPs) and the human studies that demonstrate synergy between these two compounds (GHRP + GHRH).
1390
1391NOTE: The information presented in this section was drawn generally from Refs: 1-11
1392
1393Growth Hormone Releasing Peptides (GHRPs) - A Quick Look
1394
1395What are they?
1396
1397Growth Hormone Releasing Peptides (GHRPs) are synthetic forms of the natural hormone Ghrelin. These simple short-chained amino acid peptide strings possess most of the positive characteristics of Ghrelin (such as effecting GH secretion) and few of the negative properties (such as Ghrelin's lipogenic behavior (i.e. conversion of glucose to fatty acids)).
1398
1399GHRPs belong to a broader class of compounds all of which share the common trait of being able to bind to the Growth Hormone Secretagogue Receptor (GHS-R) and effect GH release. These compounds include the synthetic peptides (GHRP-6, GHRP-1, GHRP-2, Hexarelin, Ipamorelin) and smaller synthetic non-peptide molecular compounds such as MK-0677 as well as the natural ligand Ghrelin. This broad class which includes all of the above but not Growth Hormone Releasing Hormone (GHRH) is termed Growth Hormone Secretagogues (GHSs).
1400
1401These Growth Hormone Secretagogues (GHSs) exert their effect on increasing GH output in multiple ways.
1402
1403First they INDIRECTLY increase growth hormone (GH) secretion by inducing Growth Hormone Releasing Hormone (GHRH) release from the hypothalamus in the brain. GHRH once released makes its way to the Growth Hormone Releasing Hormone Receptors (GHRH-R) in cells within the pituitary (a gland just below the brain) where it binds and exerts its direct influence in signaling GH release.
1404
1405Second these GHS also make there way to those same pituitary cells where they themselves bind to a Growth Hormone Secretagogue Receptor (GHS-R) and exert a DIRECT influence in signaling GH release. This signaling uses a different mode of action distinct from that of GHRH. As a consequence both bound GHRH & bound GHS can exert their positive influence concurrently resulting in synergistic growth hormone (GH) release.
1406
1407Third they INDIRECTLY increase GH secretion by reducing release of Somatostatin (the GH inhibiting hormone) from the hypothalamus and DIRECTLY by reducing the magnitude of Somatostatin's inhibiting action once it binds to its receptor on the pituitary cells.
1408
1409In essence Growth Hormone Secretagogues (GHS) turn up the positive signal to release GHRH, turn down the negative signal to release the inhibiting hormone Somatostatin, speak directly to the growth hormone releasing pituitary cells themselves to encourage them to release GH and speak directly to the growth hormone releasing pituitary cells themselves to encourage them to ignore Somatostatin's message to stop releasing GH.
1410
1411Oral GHS
1412
1413Based on the effectiveness of GHRPs smaller non-peptide molecules were created in an effort to mimic the GH releasing effects of GHRPs with the desire to develop a compound with high oral bioavailability. As a result MK-0677 was eventually created as a non-peptide compound with sustainedGH release and higher oral bioavailability. Unfortunately desensitization was found to occur fairly rapidly. In addition the dose for the orally administered MK-0677 is measured in several milligrams while the effective dose for the injectable GHRPs is measured in micrograms makingGHRPs more cost effective. Research is ongoing on non-peptide GHSs, particularly with Ipamorelin derivatives so perhaps an oral GHS devoid of desensitization will eventually be developed.
1414
1415My own thought is that these molecular compounds appear to be small enough to be used in a transdermal formula. Also it would be nice to have these orally/transdermally active compounds available to use on a limited basis perhaps making usage when traveling convenient.
1416
1417NOTE: The information presented in this section was drawn generally from Ref: 12
1418
1419Growth Hormone Releasing Peptides - A Longer Look
1420
1421What are they?
1422
1423In 1980 the first highly potent GH-Releasing peptide was developed and named GHRP-6. This peptide was found to illicit a strong GH release response and so became the first member of a class of growth hormone releasing peptides more broadly called GH secretagogues. StructurallyGHRP-6 is composed of the amino acids L-Histidine, D-Tryptophan, L-Alanine, L-Tryptophan, D-Phenylalanine and L-Lysine. The "L" form of an amino acid is the naturally occurring form and often in the nomenclature the "L" is dropped. The "D" form does not occur in nature and is the isomeric form (i.e. mirror image) of the naturally occurring "L" form.
1424
1425GHRP-6 is composed of both natural and isomeric forms of those aforementioned six amino acids. Its structure is represented as:
1426
1427His-D-Trp-Ala-Trp-D-Phe-Lys-NH2
1428
1429Investigators subsequently modified the structure of GHRP-6 and identified more potent peptides. For example, activity was enhanced by replacing D-Trp with D-2-(2-napthyl)alanine and His with D-Alanine to create GHRP-2 whose structure is represented as:
1430
1431D-Ala-D-2 Nal-Ala-Trp-D-Phe-Lys-NH2
1432
1433In 1982, after a long search the natural hormone "Growth Hormone Releasing Hormone" (GHRH) was finally isolated and identified. As a result the interest in Growth Hormone Secretagogues (at that point limited to the three peptides) faded. Eventually researchers discovered that those GH-Releasing Peptides (specifically GHRP-6 & GHRP-2) followed a mode of action which bound them to and was mediated through receptors different from those for GHRH. In addition researches discovered that these GH-Releasing Peptides acted synergistically with the natural hormone Growth Hormone Releasing Hormone (GHRH) in vivo (in both laboratory animals & humans) to produce large releases of Growth Hormone.
1434
1435Taken together these two discoveries made it clear that GHRPs were not simply surrogates of GHRH. GHRP-6 and its analogues were artificial activators of a separate newly discovered receptor termed the "Growth Hormone Secretagogue Receptor" (GHS-R). Eventually the natural hormone Ghrelin was discovered as the endogenous ligand that binds to the GHS-R. Together the natural hormone Ghrelin, and all the synthetic compounds (both peptides & smaller molecules) such as GHRP-6 were termed "Growth Hormone Secretagogues" (GHSs).
1436
1437This nomenclature continues in the literature to this day however increasingly new terminology is used. For instance the "Ghrelin Receptor" is synonymous with "GHS-R" and "Ghrelin mimetics" are synonymous with all the synthetic compounds that are capable of binding to the GHS-R. This paper uses the more established nomenclature throughout.
1438
1439NOTE: The information presented in this section was drawn generally from Refs: All of the Bower's studies
1440
1441Pituitary Actions of GHSs
1442
1443All GHSs act directly on the pituitary. They do so by binding to and activating their specific receptor (GHS-R). Once this occurs GH secretion is commanded to rise. GHRH does the same thing. It acts directly on the pituitary and binds to and activates its specific receptor (GHRH-R). Once this occurs GH secretion is commanded to rise.
1444
1445However GHSs and GHRH operate through a different "mode of action" or intracellular signaling system within the cell that eventually activates GHsecretion. These modes of action are contrasted as follows.
1446
1447GHRH when it binds to its receptor (GHRH-R) on the cellular membrane of a somatotrope cell activates the cAMP–PKA (cAMP-dependent proteinkinase) pathway (in essence a secondary messenger), and by a poorly understood mechanism causes a persistent rise in intracellular Calcium (Ca2+) ions by opening Ca2+ channels (simply ports on the cell membrane that open and close to either permit or deny entry) on the cellular membrane and letting into the cell Ca2+ from the outside. The rise in calcium concentration within the cell signals in conjunction with other signaling processes the instruction to the somatotrope cell to release Growth Hormone.
1448
1449It should be noted that Somatostatin (the GH inhibiting hormone) once bound to its receptor brings about a decrease in GH in part by inhibiting cAMP formation. As a consequence of limiting this messenger the signaling cascade is weakened resulting in less Calcium (Ca2+) ions entering the cell and thus inhibition of GH release.
1450
1451GHSs however do not rely on cAMP as a messenger. GHSs once bound to their respective receptor initiate a process that leads to an inhibition of Potassium (K+) ion channels. This action results in a sustained depolarization of the cellular membrane. The result is identical to that affected byGHRH, namely the Calcium ion level rises via voltage-activated channels leading to the signal to secrete GH. But the mode of action relies on the use of depolarization of the cellular membrane and inhibiting Potassium ion channels rather then GHRH's cAMP-mediated opening of Calcium ion channels.
1452
1453In addition to allowing Ca2+ into the cell, GHSs may also cause a rise in intracellular Ca2+ by redistribution from internal stores of Ca2+ within the cell. This process is mediated by the generation of inositol trisphosphate whose main functions are to mobilize Ca2+ from storage organelles and to regulate cell proliferation.
1454
1455This brief description is an over simplification. The important point is that GHRH and GHS act through their own receptors and distinct intermediate pathways.
1456
1457This is not the only difference. Although the image herein depicts one pituitary somatotrope with both types of receptors activated (GHRH-R &GHS-R) this may not give a completely accurate picture. GHRH and GHS appear to act on different somatotrope subpopulations. GHRP has been shown to increase the number of somatotropes releasing GH, without altering the amount of hormone released by each individual cell. On the other hand, GHRH stimulates both the number of cells secreting GH and the amount of GH secreted per cell.
1458
1459From these limited discoveries we can begin to understand how GHRH and GHSs compliment each other's GH releasing actions rather then duplicate one another.
1460
1461It should be noted that Somatostatin (the GH inhibiting hormone) has been shown primarily to decrease the number of cells secreting GH without affecting the amount of GH secreted per cell.
1462
1463To sum up in very general terms GHS increases, while Somatostatin decreases, the number of active GH secreting somatotropes, probably because these two factors act by depolarizing and hyperpolarizing cells, respectively (i.e. GHSs turns the cell into a Calcium ion sponge &Somatostatin turns the cell into a squeegee, squeezing out and repelling Calcium ions).
1464
1465On the other hand GHRH does both, but acts primarily by stimulating the amount of secreted GH within the active somatotropes.
1466
1467NOTE: The information presented in this section was drawn generally from Refs: 13-17
1468
1469Hypothalamic Actions of GHS
1470
1471In vitro (in a laboratory dish) the amount of GH release from GHRH and GHSs is additive. GHSs cause a rise of 2...GHRH causes a rise of 1...put them together and the GH rise is merely the sum 3.
1472
1473But something different happens when you put these two compounds into living breathing mammals. In vivo (in body) the GH rise that occurs from the combination of GHRH and GHSs is more then the sum of their individual contributions. There is substantial synergy such that 1 + 2 = 6.
1474
1475This occurs as a result of GHSs actions within the Hypothalamus (region of the brain) rather then its direct pituitary actions. There are GHSreceptors (GHS-R) in the hypothalamus; perhaps even subtype receptors. When GHSs bind to these receptors they behave like a hypothalamic neurohormone and as such exhibit a dual action.
1476
1477They stimulate endogenous GHRH release and concurrently suppress endogenous Somatostatin release. How they do this is a complex process with much still unknown. Basically they incite electrical activation of arcuate neurons (within the hypothalamus). About seventy-five percent of the cells excited by GHRP-6 project outside the blood brain barrier (hypothalamus) into the median eminence (boundary between hypothalamus & the portal system which connects to the pituitary which lies just below the brain) and are neurosecretory involved in the regulation of pituitary function.
1478
1479The activation of these neurons by GHRP-6 is extremely long lasting (longer than 1 hour) and reaches the peak rapidly (within 5 to 10 minutes). Non-peptide GHSs respond slower perhaps for the reason that they penetrate the blood brain barrier slower than GHRP-6.
1480
1481GHRP-6s excitation of neuronal activity beyond those neurons that regulate GHRH & Somatostatin (i.e. the remaining 25%) may account for some of the impact GHRPs have on non-GH releasing activity.
1482
1483The important point is to recognize that GHSs have an impact on GHRH release and Somatostatin suppression at the hypothalamus which appears to be responsible for the now well-recognized synergistic effect on GH release from concurrent administration of GHRH & GHRPs in vivo.
1484
1485Furthermore it should now be firmly understood that GH release is regulated by the following trinity - GHRH, Somatostatin and GHSs.
1486
1487NOTE: The information presented in this section was drawn generally from Refs: 13-5, 9, 18
1488
1489GHS Potency (i.e. efficacy) & Dosing in Humans
1490
1491When administered at clinical research dosages, all GHSs (both peptides and non-peptides) release significantly larger amounts of GH (i.e. are more efficacious) than GHRH. This is not to be confused with the term potency which takes into account the molecular weight of a compound and thus measures GH output on a "per mol" basis. By this measure GHRH is more potent.
1492
1493However if the desire is to administer these compounds and effect GH release then the only relevant standard is absolute amount of GH release and in that regard GHSs release more GH than GHRH. The following standards determined through clinical study will specifically clarify this concept.
1494
1495In humans the maximal i.v. dose for GHRH has been found to be 1 mcg per kg of bodyweight. That is a level that saturates the receptors and beyond which there is no further benefit, until that dosage has dissipated.
1496
1497In humans the maximal i.v. dose for GHSs such as hexarelin has been found to be 2 to 3 mcg per kg of bodyweight. In normal humans (i.e. those without disease or clinical malady) GH release is increased as the GHS dose increases up to the aforementioned maximal dose. Even very small amounts have been shown to have positive effects.
1498
1499Unlike GHRH, GHSs are resistant to well-known inhibitors of GH secretion. Studies demonstrate that hexarelin-mediated GH secretion is reduced but not blocked by a rise in circulating free fatty acids or by a glucose load, nor by an infusion of Somatostatin nor drugs that enhance hypothalamic Somatostatin secretion.
1500
1501GHRH is influenced by metabolic and hormonal factors that consequently make GHRH a very unpredictable GH stimulator, with large variations between individuals and a diversity of peaking times.
1502
1503In contrast GHSs are not greatly influenced by metabolic and hormonal factors, the absence of which makes GHSs a very predictable GHstimulator. GHSs are potent and efficacious, their actions synchronized and reproducible, with no non-responders.
1504
1505GHSs have been repeatedly demonstrated in studies to be very strong GH releasers in healthy young males. In addition GHSs have been shown in studies to be very strong GH releasers in females at all stages of the menstrual cycle. This again is important to note because GHSs are not greatly affected by changes in various hormone levels, be they thyroid hormone, estrogen, etc.
1506
1507There may be an age-related reduction in the GH-releasing capability of GHSs. The studies have not yet been able to come to a consensus. However, the synergistic effect of GHRH and GHS on GH secretion is not reduced as humans age throughout the entire lifespan. This holds true even for the very old (Those in their 90's).
1508
1509There are no reported side-effects with GHS usage. However both the peptidyl and non-peptidyl compounds have been found to induce slight increases (still within what is deemed the normal range) in prolactin and in adrenocorticotrophin(ACTH)/cortisol, and in a few studies dehydroepiandrosterone (DHEA). Low to moderate dose (1 mcg/kg) administration of GHRP-6 has been found to result in very large GH release with no significant effects on cortisol or prolactin. Of the peptides, Hexarelin appears to induce the highest level of these hormones (prolactin & cortisol). Ipamorelin a newer GHS has no effect on these hormones no matter what the dose.
1510
1511NOTE: The information presented in this section was drawn generally from Refs: 19-31
1512
1513Why you need both GHRH analog (CJC-1295) and GHRP
1514
1515GHS Down Regulation
1516
1517A single dose of a GHS in vivo brings about an immediate down-regulation of responsiveness to subsequent administration. This desensitization appears to abate and sensitivity fully restored within a few hours.
1518
1519However continual infusion of large amounts of GHS brings about a substantial initial release of GH, followed, after several hours, by long-term down-regulation of GH secretion.
1520
1521The only published comparison of the results of differing modes of GHS delivery (twice daily injections vs. continuous infusion) in vivo demonstrated a dramatic dissipation of anabolism following infusions of high-dose GHS. However a pronounced anabolic effect was maintained with the same dose of GHS administered by intermittent injection.
1522
1523From the results of this study graphed out above it is evident that with GHSs the optimal dosing pattern is administration by injection with sufficient intervals between dosing so as to maintain sensitivity.
1524
1525The effectiveness is greatly diminished, perhaps to the point of having no benefit if GHSs duration of action becomes prolonged and sustained.GHSs unlike GHRH are best used to amplify those very import GH pulses while GHRH is effective at raising the total level of GH.
1526
1527If we understand desensitization than we will easily understand why the oral GHS, MK-0677 in recent studies failed to demonstrate a "maintained acceleration of statural growth in children with GH-deficiency". MK-0677 was developed to be a long lasting orally active analogue of GHRP-6. MK-0677 is to GHRP-6 what CJC-1295 is to GHRH (i.e. long-lasting).
1528
1529The problem is that while long-lasting analogues of GHRH do not result in desensitization and pronounced down-regulation, long-lasting analogues of GHRP-6 do desensitize and consequently lose effectiveness.
1530
1531CJC-1295 brings about persistent and chronically elevated levels of GH while GHRP-6 if injected a couple of times a day amplifies the very important GH pulses. The two compounds greatly compliment each other. In the previous article on GHRH & CJC-1295 we discussed the importance of pulsation which has been shown to be necessary for growth. The other important component of anabolism is chronic GH elevation.
1532
1533Continuously elevated levels of GH increase IGF-I levels more than intermittent increases in GH. The intermittent nature of GH release brought on by GHSs' mode of action does create a rise in IGF-I levels but the anabolic effect may not be pronounced.
1534
1535It has been repeatedly demonstrated and is now recognized that in children the growth response to injections of IGF-I is far less than the growth response to injections of GH. This is in accordance with most animal studies, which demonstrate that treatment with IGF-I does "not produce the full anabolic and growth-promoting effects of GH treatment".
1536
1537Protocols that elevate GH while maintaining and amplifying the pulses seem to be effective at producing anabolism. The combination of CJC-1295 and GHRP-6 do just that.
1538
1539NOTE: The information presented in this section was drawn generally from Refs: 32-37
1540
1541GHRH (and analogs) + GHSs = a lot of synergistic growth hormone release
1542
1543There is not a lot of deviation in the published studies on the effect of these peptides and the saturation dose needed to bring about the effect in normal people (who often act as a control group).
1544
1545We need only to examine the results of the normal test subjects from three oft-cited studies that established the relevant protocol.
1546
1547In the first study "Inhibition of growth hormone release after the combined administration of GHRH and GHRP-6 in patients with Cushing's syndrome", Alfonso Leal-Cerro..., Clinical Endocrinology 1994, 41 (5) , 649–654, three different peptide/peptide combinations were used.
1548
1549GHRH was administered alone at 100mcg. This resulted in area under the curve (AUC) measured for 120 minutes of GH secretion of 1420 ± 330.
1550
1551GHRP-6 was administered alone at 100mcg. This resulted in area under the curve (AUC) measured for 120 minutes of GH secretion of 2278 ± 290.
1552
1553GHRH plus GHRP-6 was administered together at 100mcg each. This resulted in area under the curve (AUC) measured for 120 minutes of GHsecretion of 7332 ± 592.
1554
1555As a single dose these results show that GHRP-6 is about twice as effective as GHRH.
1556
1557The synergy between GHRH & GHRP-6 is clearly evident as co-administration resulted in twice the benefit of the additive values of single doses of the two peptides.
1558
1559The second study is the one that established the saturation dose for these peptides often used in other studies. "Growth hormone (GH)-releasing peptide stimulates GH release in normal men and acts synergistically with GH-releasing hormone ", CY Bowers..., J. Clin. Endocrinol. Metab., Apr 1990; 70: 975-982.
1560
1561In that study GHRH at a dose of 1.0 microgram/kg was administered alone and then together with various doses of GHRP-6 (0.1, 0.3, and 1.0 microgram/kg). They found that the submaximal dosages of 0.1 and 0.3 microgram/kg GHRP-6 plus 1 microgram/kg GHRH did have the effect of stimulating GH release synergistically.
1562
1563However the larger dose of 1 mcg/kg of GHRP-6 was found to be the saturation dose when used in combination w/ 1 mcg/kg of GHRH.
1564
1565It is also noteworthy that serum prolactin and cortisol levels rose about 2-fold above base levels only at the 1 microgram/kg dose of GHRP-6 and not at the submaximal dosages.
1566
1567The final study, "Preserved Growth Hormone (GH) Secretion in Aged and Very Old Subjects after Testing with the Combined Stimulus GH-Releasing Hormone plus GH-Releasing Hexapeptide-6", Micic D..., J Clin Endocrinol Metab. 1998 Jul;83(7):2569-72 is fascinating for several reasons.
1568
1569By reference to citation it is noted that "GHRH plus GHRP-6 (both at saturating dose) is nowadays considered the most potent stimulus of GHsecretion in man being able to restore the GH secretion in states associated with chronic blockade of somatotroph activity (as in obesity)...it elicits a near-normal GH discharge in obesity, in patients with hypothyroidism and in patients with type 2 diabetes mellitus."
1570
1571This particular study examined the effects of combined administration of GHRH, immediately followed by GHRP-6 in a group of very old subjects (age higher than 75 yr), as compared with both normal adults (less than 40 yr) and aged subjects (age 46–65 yr). The dosing levels used were 90mcg of GHRH followed by 1mcg/kg of GHRP-6.
1572
1573All the subjects had a positive GH secretory response to the combined administration with no differences observed between men and women. However the group comprising the very old had the highest level of GH release followed by the group comprising the aged subjects with the "less than 40 yr group" experiencing a substantial rise but not as high as the other two groups.
1574
1575The study concluded that the lack of side-effects & safety of the protocol and the discovered lack of age-related decline in the "GHRH-GHRP-6-mediated GH release opens the possibility of using it as a therapeutical tool to revert some deleterious manifestations of aging in man."
1576
1577In CONCLUSION, Growth Hormone (GH) is regulated by a trinity composed of Growth Hormone Releasing Hormone (GHRH), Growth Hormone Secretagogues (GHS) and Somatostatin. GHRH and GHSs individually have a positive impact on GH secretion. These two compounds operate through distinct modes of action which complement each other and when administered together result in synergistic GH secretion.
1578
1579Growth Hormone Releasing Peptides (GHRPs), a subclass of GHSs are effective across all age groups in amplifying GH pulses. Pulsation is a necessary component of growth generation in mammals. GHRH when co-administered with GHRPs has the effect of further increasing the amplitude and "area under the curve" of a GH pulse. The result is a GH pulse many multiples more effective then that achieved by an unaided GH pulse.
1580
1581In addition to pulsation, overall growth is better accomplished when total levels of GH are elevated without hindering pulsation. Elevated GH levels appear to be a necessary component of growth generation as well. One of the reasons this is so appears to be that chronically elevated GH levels result in more pronounced sustained levels of IGF-1 then that achieved through intermittent GH elevations.
1582
1583Persistent levels of GHRH do not result in desensitization. Elevated levels of GHRH result in sustained GH release. A long-lasting version of GHRH, CJC-1295 has demonstrated the ability to sustain elevated GH levels in humans.
1584
1585GHRP-6 is perhaps the most well studied of all GHSs. In physiological doses there are virtually no side effects. It has been demonstrated to be effective for all age groups.
1586
1587Combined administration of CJC-1295 and GHRP-6 is a very effective, well studied method of increasing the total amount of GH secreted within the body. By adjusting the dosing of these compounds and accounting for such factors as age one may choose to achieve a "youthful" restoration, an above normal elevation or a substantially above normal elevation of both GH levels and pulsatile release.
1588
1589References:
1590
1591    Bowers CY, Momany F, Reynolds GA. In vitro and in vivo activity of a small synthetic peptide with potent GH releasing activity. 64th Annual Meeting of the Endocrine Society, San Francisco, 1982, p. 205
1592
1593    Bowers CY, Momany F, Reynolds GA, Sartor O. Multiple receptors mediate GH release. 7th International Congress of Endocrinology, Quebec, Canada, 1984, p. 464.
1594
1595    Badger RM, Millard WJ, McCormick GF, Bowers CY, Martin JB. The effects of growth hormone (GH) releasing peptides on GH secretion in perifused pituitary cells of adult male rats. Endocrinology 1984;115:1432–1438.
1596
1597    McCormick GF, Millard WJ, Badger TM, Bowers CY, Martin JB. Dose-response characteristics of various peptides with growth hormone-releasing activity in the unanesthetized male rat. Endocrinology 1985;117:97–105.
1598
1599    Sartor O, Bowers CY, Chang D. Parallel studies of His-DTrp-Ala-Trp-DPhe-Lys-NH2 and hpGRF-44NH2 in rat primary pituitary cell monolayer culture. Endocrinology 1985;116:952–957.
1600
1601    Sartor O, Bowers CY, Reynolds GA, Momany F. Variables determining the GH response of His-D-Try- Ala-Trp-D-Phe-Lys-NH2 (GH-RP-6) in the rat. Endocrinology 1985;117:1441–1447.
1602
1603    Bowers CY, Sartor O, Reynolds GA, Chang D, Momany F. Evidence that GRF and GRP, His-DTrp-Ala- Trp-DPhe-Lys-NH2, act on different pituitary receptors to release GH. 67th Annual Meeting of the Endocrine Society, Baltimore, MD, 1985, p. 38.
1604
1605    Bowers CY, Sartor O, Reynolds GA, Chang D. Studies in subhuman primates with growth hormone releasing peptides. 68th Annual Meeting of the Endocrine Society, Anaheim, CA, 1986, p. 146.
1606
1607    Reynolds GA, Bowers CY. In vitro studies with GH releasing peptides. 69th Annual Meeting of the Endocrine Society, Indianapolis, 1987, p. 49.
1608
1609    Reynolds GA, Momany GA, Bowers CY. Synthetic tetrapeptides that release GH synergistically in combination with GHRP and GHRH. 73rd Annual Meeting of the Endocrine Society, Washington, D.C., 1991, p, 422.
1610
1611    Bowers CY, Sartor AO, Reynolds GA, Badger TM. On the actions of the growth hormone-releasing hexapeptide, GHRP-6. Endocrinology 1991;128:2027–2035.
1612
1613    Franco Camanni, Ezio Ghigo, and Emanuela Arvat, Growth Hormone-Releasing Peptides and Their Analogs. Frontiers In Neuroendocrinology 19, 47–72 (1998) ARTICLE NO. FN970158
1614
161513 Bowers, C.Y. (1996) Xenobiotic growth hormone secretagogues: growth hormone releasing peptides. In Growth Hormone Secretagogues (Bercu, B.B. and Walker, R.F., eds), pp 9–28, Springer-Verlag
1616
161714 Bercu, B.B., Yang, S-W., Masuda, R. and Walker, R.F. (1992) Role of selected endogenous peptides in growth hormone releasing hexapeptide (GHRP) activity: analysis of GHRH, TRH and GnRH. Endocrinology 130, 2579–2586
1618
161915 Chen, C., Wu, D. and Clarke, I.J. (1996) Signal transduction systems employed by synthetic GH-releasing peptides in somatotrophs. J. Endocrinol. 148, 381–386
1620
162116 Frohman, L.A., Downs, T.R. and Chomczynski, P. (1992) Regulation of growth hormone secretion. Front. Neuroendocrinol. 13, 344–405
1622
162317 Goth, M.I., Lyons, C.E., Canny, B.J. and Thorner, M.O. (1992) Pituitary adenylate cyclase activating polypeptide, growth hormone (GH)-releasing peptide and GH-releasing hormone stimulate GH release through distinct pituitary receptors. Endocrinology 130, 939–944
1624
1625    Bowers CY, Reynolds GA, Chang D, Hong A, Chang K, Momany F. A study on the regulation of GH release from the pituitary of rats, in vitro. Endocrinology 1981;108(3):1070–1079.
1626
1627    Bowers, C.Y., Reynolds, D.G., Durham, D., Barrera, C.M., Pezzoli, S.S. and Thorner, M.O. (1990) Growth hormone (GH)-releasing peptide stimulates GH release in normal men and acts synergistically with GH-releasing hormone. J. Clin. Endocrinol. Metab. 70, 975–982
1628
1629    Penalva, A., Carballo, A., Pombo, M., Casanueva, F.F. and Dieguez, C. (1993) Effect of growth hormone (GH)-releasing hormone (GHRH), atropine, pyridostigmine or hypoglycemia on GHRP- 6-induced GH secretion in man. J. Clin. Endocrinol. Metab. 76, 168–171
1630
1631    Penalva, A., Pombo, M., Carballo, A., Barreiro, J., Casanueva, F.F. and Dieguez, C. (1993) Influence of sex, age and adrenergic pathways on the growthhormone response to GHRP-6. Clin. Endocrinol. 38, 87–91
1632
163322 Micic, D., Popovic, V., Kendereski, A., Peino, R., Dieguez, C. and Casanueva, F.F. (1996) The sequential administration of growth hormone-releasing hormone followed 120 minutes later by hexarelin, as an effective test to assess the pituitary GH reserve in man. Clin. Endocrinol. 45, 543–551
1634
1635    Ghigo, E. et al. (1994) Growth hormone releasing activity of hexarelin, a new synthetic hexapeptide, after intravenous, subcutaneous, and oral administration in man. J. Clin. Endocrinol. Metab. 78, 693–698
1636
1637    Peino, R., Cordido, F., Peñalva, A., Alvarez, C.V., Dieguez, C. and Casanueva, F.F. (1996) Acipimox-mediated plasma free fatty acid depression per se stimulates growth hormone (GH) secretion in normal subjects and potentiates the response to other GH-releasing stimuli. J. Clin. Endocrinol. Metab. 81, 909–913
1638
1639    Ghigo, E., Arvat, E., Muccioli, G. and Camanni, F. (1997) Growth hormone releasing peptides. Eur. J. Endocrinol. 136, 445–460
1640
1641    Hartman, M.L., Farello, G., Pezzoli, S.S. and Thorner, M.O. (1992) Oral administration of growth hormone (GH)- releasing peptide administration stimulates GH secretion in normal men. J. Clin. Endocrinol. Metab. 74, 1378–1384
1642
1643    Gertz, B.J. et al. (1993) Growth hormone response in man to L-692,429, a novel nonpeptide mimic of growth hormonereleasing peptide-6. J. Clin. Endocrinol. Metab. 77, 1393–1397
1644
1645    Micic, D., Popovic, V., Kendereski, A., Macut, D., Casanueva, F.F. and Dieguez, C. (1995) Growth hormone secretion after the administration of GHRP-6, or GHRP-6 plus GHRH does not decline in late adulthood. Clin. Endocrinol. 42, 191–194
1646
1647    Micic, D., Popovic, V., Doknic, M., Macut, D., Dieguez, C. and Casanueva, F.F. (1998) Preserved growth hormone (GH) secretion in aged and very old subjects after testing with the combined stimulus GH-releasing hormone plus GH-releasing hexapeptide-6. J. Clin. Endocrinol. Metab. 83, 2569–2572
1648
1649    Massoud, A.F., Hindmarsh, P.C. and Brook, D.G.D. (1996) Hexarelin-induced growth hormone, cortisol, and prolactin release: a dose-response study. J. Clin. Endocrinol. Metab. 81, 4338–4341
1650
1651    Raun, K. et al. (1998) Ipamorelin, the first selective growth hormone secretagogue. Eur. J. Endocrinol. 139, 552–561
1652
1653    Smith RG, Pong SS, Hickey Get al. Modulation of pulsatile GH release through a novel receptor in hypothalamus and pituitary gland. Rec Prog Horm Res 1996; 51: 261-286.
1654
1655    McDowell KS, Elias KA, Stanley MS et al Growth-hormone secretagogues - characterization, efficacy, and minimal bioactive conformation. Proc Natl Acad Sci U S A 1995; 92: 11165-11169.
1656
1657    Howard AD, Feighner SD, Cully DF et al. A receptor in pituitary and hypothalamus that functions in growth hormone release. Science 1996; 273: 974-977.
1658
1659    Pong SS, Chaung LYE Dean DC, Nargund RP, Patchett AA, Smith RG. Identification of a new G-proteinqinked receptor for growth-hormone secretagogues. MoI Endocrinol 1996; 10: 57-61.
1660
1661    Clark RG, Robinson ICAE Up and down the growth hormone cascade. Cytokine Growth Factor Rev 1996; 7: 65-80.
1662
1663    Yu H, Cassorla F, Tiulpakov A et al. A double blind placebocontrolled efficacy trial of an oral growth hormone (GH) secretagogue (MK-0677) in GH deficient (GHD) children. 80th Annual Meeting US Endocrine Society, New Orleans, Louisiana, 1998;
1664
1665Growth Hormone Administration vs. CJC-1295/GHRP-6 + GHRH
1666
1667Units of Measurement
1668
1669Growth Hormone (GH) like other biologically active substances is measured in International Units (abbreviated as IU) which are based on the measured biological activity for that substance the establishment of which is determined by international agreement. International Units are specific to each substance and so one IU of one substance has no equivalence to one IU of another substance.
1670
1671While it is fairly straightforward to compare the amount of GH among various dosing administrations (a two (2) iu dose is twice the amount of a four (4) iu dose) and it is easy to ask the manufacture the weight of each iu (Nutropin reveals that 1 iu of their GH is equal to 333 mcg while Lilly's Humatrope trials define 1 iu as 370 mcg (2.7iu per 1mg)) it is not so simple to compare Growth Hormone to other "Growth Hormone Releasing" compounds such as CJC-1295 and GHRP-6.
1672
1673Practically all studies that use Growth Hormone (GH) or Growth Hormone Releasing Hormone (GHRH) or its analog CJC-1295 or Growth Hormone Releasing Peptides all take blood samples to measure the amount of GH present in blood plasma at various points in time. The unit of measurement is a standardized unit which can be used to make comparisons across different compounds.
1674
1675The studies either report results as "nanograms (ng) per milliliter (ml)" or "micrograms (ug) per liter (L)". For the reason that ng = 1/1000 ug and ml = 1/1000 L, ng/ml will always equal ug/L. So no matter how the studies report results comparison is straightforward. In making the cross-comparisons contained herein for simplicity I have chosen to report results as ng/ml.
1676
1677In addition the amount of hormone released into plasma (i.e. concentration) is based on units divided by time. This measurement is called area under the curve (AUC). However some studies will use the hour as the unit of time while others will use the minute. Therefore comparing AUCs between studies using different units of time requires a conversion to a common unit of time.
1678
1679I will make the conversion herein in written form but be careful when you look at graphs.
1680
1681Therefore this examination will look to several studies involving administration of the compounds of interest and compare the blood plasma levels of GH and peak concentration as a result of administration of each tested compound. The result of this cross-study examination will reveal the efficaciousness of various doses of GH, CJC-1295 and GHRH + GHRP-6 in increasing GH in blood plasma.
1682
1683Studies used for comparison
1684
1685Growth Hormone Administration
1686
1687The primary study used herein is the Lilly Clinical trial using single dose administration of Humatrope in normal adults to assess pharmacokinetics. The doses used were .05 IU/kg (intravenously) and .27iu/kg (subcutaneously and intramuscular). In an 80kg adult that equates to 4iu and about 22iu. In our comparison we will only look at the 22iu subcutaneous and intramuscular dose.
1688
1689CJC-1295 Administration
1690
1691In "Prolonged Stimulation of Growth Hormone (GH) and Insulin-Like Growth Factor I Secretion by CJC-1295, a Long-Acting Analog of GH-Releasing Hormone, in Healthy Adults", Sam L. Teichman, et al. Journal of Clinical Endocrinology & Metabolism 91(3):799-805, sixty-six healthy normal men and women aged 21-61 were administered various doses of CJC-1295 (long-lasting GHRH analog). The CJC-1295 was administered in a single dose and again in some groups 7 days later and other groups 14 days later. For the reason that we are only examining a week's worth of data only the initial dose is of interest. Blood samples were collected before dosing and then at 15, 30, and 60 minutes and 2, 3, 4, 6, 8, 10, 12, and 24 hours afterdosing; and then every 8 hours on days 2–3, then daily on days 4, 5, 6, 7.
1692
1693The doses administered were: 30mcg/kg; 60mcg/kg; 125mcg/kg; 250mcg/kg
1694
1695GHRH + GHRP-6 Administration
1696
1697While we are limited in our choice of GH administration studies and CJC-1295 studies (there are only two, the results of which are available to the public) we have many available studies measuring the effects of co-administration of GHRH and GHRPs.
1698
1699So we will briefly look at the results from two studies to give us an idea of how much GH release is contributed by the enhanced pulse brought on by this synergistic combination.
1700
1701They are, "Inhibition of growth hormone release after the combined administration of GHRH and GHRP-6 in patients with Cushing's syndrome", Alfonso Leal-Cerro, et al., Clinical Endocrinology 1994, 41 (5) , 649–654
1702
1703and
1704
1705"Growth hormone (GH)-releasing peptide stimulates GH release in normal men and acts synergistically with GH-releasing hormone", Bowers, C.Y., et al. J. Clin. Endocrinol. Metab. 70, 975–982.
1706
1707What's Normal?
1708
1709Before we look at the studies lets take a brief look at how much growth hormone (GH) is secreted naturally.
1710
1711The following very comprehensive study measured growth hormone output over twenty-four hours among healthy normal people of all ages.
1712
1713Age-Related Changes in Slow Wave Sleep and REM Sleep and Relationship With Growth Hormone and Cortisol Levels in Healthy Men, Eve Van Cauter, PhD; Rachel Leproult, MS; Laurence Plat, MD, JAMA. 2000; 284:861-868
1714
1715The youngest category, those under 25 years of age secrete about 2iu of GH per 24 hours, while those in older categories sectrete 1 iu or less.
1716
1717Note that Humatrope indicates that absolute bioavailability of an intramuscular or subcutaneous dose is about 66%. So perhaps 3iu of exogenously administered synthetic GH is a replacement dose equivalent to 2iu of indogenously secreted GH.
1718
1719Comparing GH administration to CJC-1295 administration
1720
1721Total GH Release:
1722
1723When CJC-1295 was administered at 30mcg/kg; 60mcg/kg; 125mcg/kg and 250mcg/kg the total GH levels (area under the curve (AUC)) were respectively:
1724
1725AUC: 758, 969, 977, and 1370 ng/ml per hour
1726
1727Keep in mind that for a 80kg adult the 30mcg/kg dosing amounts to 2.4mgs of CJC-1295 per week and the 60mcg/kg dosing amounts to 4.8mgs of CJC-1295.
1728
1729So 2.4 mgs of CJC-1295 produced an AUC of 758 ng/ml per hour.
1730
1731When synthetic Growth Hormone (Humatrope) was administered at the equivalent of 22iu (in someone weighing 80+ kg) the following GH levels (area under the curve (AUC)) were reached:
1732
1733AUC Intramuscular: 495 +/- 106
1734
1735AUC Subcutaneous: 585 +/- 90
1736
1737Peak Concentration:
1738
1739However the GH release pattern results in a much higher mean maximum concentration for the GH administration than the CJC-1295 administration.
1740
1741The GH study resulted in peaks of 53 to 63 ng/ml.
1742
1743The CJC-1295 study resulted in dose respected peaks of 6.6; 9.6; 9.9; 13.3 ng/ml.
1744
1745Comparing GH administration to GHRP + GHRH administration
1746
1747Total GH Release:
1748
1749The Alfonso Leal-Cerro study demonstrated the following GH release:
1750
1751GHRH by itself dosed at 100mcg resulted in: (AUC) 120 minutes = 1420 ± 330 ng/ml when we convert that to AUC measued in hours we get about: 25 ng/ml
1752
1753GHRP-6 by itself dosed at 100mcg resulted in: (AUC) 120 minutes = 2278 ± 290 ng/ml when we convert that to AUC measued in hours we get about: 40 ng/ml
1754
1755GHRH + GHRP-6 dosed together at 100mcg each resulted in: (AUC) 120 minutes = 7332 ± 592 ng/ml when we convert that to AUC measued in hours we get about: 130 ng/ml The Bowers study demonstrated that a small dose of GHRP (.1mcg/kg) added to a saturation dose of GHRH (1mcg/kg) resulted in the following GH release:
1756
1757(AUC) 120 minutes = 10,065 ng/ml when we convert that to AUC measued in hours we get about: 170 ng/ml
1758
1759In comparison to synthetic GH administration we find that:
1760
176122iu of synthetic GH results in 495 - 585 ng/ml Saturation doses of GHRH & GHRP results in 130 - 170 ng/ml
1762
1763These results indicate that 22iu is between 3.8 and 3.4 more efficacious then a single administration of GHRH & GHRP which means that a single dose of GHRH & GHRP has the potential to produce better then the equivalent of 5iu of GH in plasma.
1764
1765A dosing protocol of GHRH + GHRP at saturation dose, administered 3 times per day has the potential to exceed the equivalent of 15iu.
1766
1767Note though that using this methodology GHRP-6 at a saturation dose by itself may add the equivalent of 1.4 to 1.8 iu per administration... or 4.2 to 5.4 iu per day if administered three times.
1768
1769Peak Concentration:
1770
1771From the graphs it is easy to see that GHRH+GHRP results in short-term peaks of 80 to 130 ng/ml.
1772
1773While the synthetic GH study resulted in less pronounced peaks of 53 to 63 ng/ml of longer duration.
1774
1775Systemic IGF-1 levels
1776
1777Simply stated the synthetic Growth Hormone when administered intramuscularly or subcutaneously in high enough dose results in a release profile that is not pulsatile. The release profile is an elevation and this elevation results in higher levels of systemic IGF-1 in circulation then either an intravenous administration of GH or administration of the pulsatile peptides.
1778
1779While multiple daily dosings of GHRH/GHRP result in a significant rise in systemic IGF-1 (not graphed out here) they do not over time result in as substantial an elevation of circulating IGF-1 as synthetic GH administered non-intravenously.
1780
1781To understand the difference in GH in plasma profile of synthetic GH administered by intravenous I provide a copy of the GH study graph identical to the clinical study graph posted above with the addition of the intravenous dosing of GH. As you can see intravenous dosing of GH results in what could be described as a pulse because GH is elevated very high and then clears quickly.
1782
1783So what does a high dose of synthetic GH administered subcutaneously or intramuscularly (but not by IV) do to systemic levels of IGF-1?
1784
1785To find out we must switch to a Japanese study which undertook such study.
1786
1787In Pharmacokinetics and Metabolic Effects of High-Dose Growth Hormone Administration in Healthy Adult Men, Toshiaki Tanaka, et al., Endocrine Journal 1999, 46 (4), 605-612, fifteen healthy normal Japanese adult males aged from 20 to 27 years were administered various doses of recombinant GH (Norditropin). The GH was administered in a single dose at 9:00 a.m. after overnight fasting. Blood samples were collected at 0, 1, 2, 3, 4, 5, 6, 9, 12 and 24 hours after the single injection.
1788
1789The doses administered were: .075iu/kg; .15iu/kg and .30iu/kg When the average weight of each test subject is accounted for the doses administered approximated: 5iu; 10iu and 20iu
1790
1791In the higher dose category the study dosed every day for a week and collected blood samples each day.
1792
1793IGF-1 levels were measured and can be graphed as follows:
1794
1795From this graph a few quick things can clearly be understood:
1796
1797• IGF-1 creation is a slow ongoing process that increases every day that you administer GH until it plateaus after a week. This should tell you that there is no fear that anything will specifically interfere with GH's ability to instigate IGF-1 creation. All of the timing protocols which fear that insulin or "this and that" will interfere with IGF-1 creation are baseless and such "write-ups" that call for timing are flawed. • It is constant GH elevations that result in ever higher levels of systemic IGF-1 creation
1798
1799What none of this tells us
1800
1801This does not tell us what is happening locally. By locally I mean IGF-1 that is not made in the liver and circulated systemically. Local IGFs are made in small amounts and used exclusively in the tissue of their birth.
1802
1803Local IGF-1 in muscle has been demonstrated to be responsible for muscle growth and only if muscle-made IGF-1 is lacking does systemic IGF-1 play a significant (although incomplete) role.
1804
1805Local IGFs in muscle are increased by growth hormone and testosterone. It is conjectured that pulsatile GH (such as IV dosing) or the use of GHRH/GHRPs results in high levels of muscle IGFs w/o creating high levels of systemic circulating IGFs.
1806SWS & GH release
1807
1808There are two types of sleep, rapid eye movement (REM) and non-rapid eye movement (NREM). Sleep proceeds in cycles composed of four types of stages of NREM and a stage of REM usually ordered as: 1 > 2 > 3 > 4 > 3 > 2 > REM
1809
1810The cycle lasts on average 90 to 110 minutes, with a greater quantity of stages 3 and 4 experienced early in the night and more REM later in the night.
1811
1812NREM accounts for 75–80% of total sleep time. Non-REM is comprised of four stages; stages 1 and 2 are considered 'light sleep', and 3 and 4 'deep sleep' or slow-wave sleep (SWS).
1813
1814It has been shown that sleep, more specifically slow-wave sleep (SWS), does affect growth hormone levels in adult men. During eight hours sleep, it has been demonstrated in several studies that the men with a high percentage of SWS (average 24%) also had high growth hormone secretion, while subjects with a low percentage of SWS (average 9%) had low growth hormone secretion.
1815
1816In one very complete study referenced by several others, it was demonstrated that “GH secretory rates and peripheral GH concentrations were maximally correlated with sleep stage, with lags of 4.5 and 16 min, respectively, suggesting that maximal GH release occurs within minutes of the onset of stage 3 or 4 sleep”.
1817
1818Furthermore “sleep-related augmentation of GH secretion… usually occurs around midnight and the GH levels at that time are, as a rule, at their highest during the 24-hour period. Partially, this phenomenon is time-entrained and partially related to sleep itself. It is associated with a slow wave sleep, and the maximal GH levels occur within minutes of the onset of slow wave sleep” -Holl RW, Hartman ML, Veldhuis JD, et al. Thirty-second sampling of plasma growth hormone in man: correlation with sleep stages. J Clin Endocrinol Metab 1991;72:854–61.
1819
1820The origin of nocturnal GH release in humans is still unknown. Most likely hypothalamic GHRH release is a major contributing component, but an additional role of another factor, presumably augmenting GHRH responsiveness of the somatotrophs, is likely. However the precise explanatory mechanisms are still not fully identified.
1821
1822It is worth reiterating though that nocturnal release of GH makes up only a fraction of the total daily GH release in women, but the bulk of GH output in men.
1823Modified GRF(1-29) is different then GRF(1-29)
1824
1825NOTE that native GRF(1-29) is native GHRH or GRF(1–44) with the inactive final 15 amino acids removed.
1826
1827It is very important to use ONLY modified GRF(1-29) w/ the four amino acid substitutions as discussed before and NOT unmodified GRF(1-29) Enhanced stability and potency of novel growth hormone-releasing factor (GRF) analogues derived from rodent and human GRF sequences, Robert M. Campbell, Peptides Volume 15, Issue 3, 1994, Pages 489-495
1828
1829Native human GRF(1–44)-NH2 (hGRF44) is subject to biological inactivation by both enzymatic and chemical routes. In plasma, hGRF44 is rapidly degraded via dipeptidylpeptidase IV (DPP-IV) cleavage between residues Ala [at the 2nd position] and Asp [at the 3rd position]. The hGRF44 is also subject to chemical rearrangement [at the 8th position] and oxidation [at the 27th position] in aqueous environments, greatly reducing its bioactivity.
1830
1831It is therefore advantageous to develop long-acting GRF analogues using specific amino acid replacements at the amino-terminus [2nd position] (to prevent enzymatic degradation): residue 8 (to reduce isomerization) and residue 27 (to prevent oxidation). Inclusion of Ala [at the 15th position] substitution for Gly, previously demonstrated to enhance receptor binding affinity, would be predicted to improve GRF analogue potency.
1832
1833In vitro, these analogues were approximately threefold more potent than hGRF44, whereas in vivo they were eleven- to thirteenfold more potent. As the in vitro results reflect only receptor affinity and signal transduction, the increment in potency observed in vivo is likely due to the increased biological half-life of these analogues (i.e., the result of decreased enzymatic and chemical decomposition such that more bioactive peptide is available per unit time). So these changes are made to reduce enzymatic cleavage, amino rearrangement and oxidation in plasma.
1834
1835In addition "Ala [position] 15-substitution (for Gly) displayed 4–5 times higher affinity for the GRF receptor relative to hGRF(1–44)-NH2...and hence potency." - GRF analogs and fragments: Correlation between receptor binding, activity and structure, Robert M. Campbel, Peptides Volume 12, Issue 3, May-June 1991, Pages 569-574
1836
1837So the above highlighted amino acids need to be modified to:
1838
18392nd position - D-Ala 8th position - Gln 15th position - Ala 27th position - Leu
1840How GHRPs are cardio-protective
1841
1842The growth hormone secretagogues (GHS) are a family of synthetic compounds originally selected for their potent and specific effects on GH release. Nonetheless, it has been reported by us and other researchers that the GHS have also many extraendocrine actions, including those on energy metabolism and cardiovascular function. Ghrelin, the endogenous GHS, specifically binds to the GHS-R1a, a receptor that has been proposed to mediate the biological activities of endogenous and synthetic GHS.
1843
1844The activation of the GHS-R1a is not enough to explain the results that we have previously reported on the ability of hexarelin, a synthetic full agonist of the GHS-R1a, to protect the rat heart from the damage induced by the ischemia-reperfusion procedure. In fact, the GHS-R1a is not expressed in the myocardium, and ghrelin is much less effective than hexarelin in protecting the heart from ischemia-reperfusion damage.
1845
1846Moreover, it has also been demonstrated that in the cardiovascular system hexarelin and other GHS can also bind to the CD36, a scavenger receptor.
1847
1848Interestingly, a large similitude exists between the cardioprotective effects of hexarelin and those of some angiotensin-converting enzyme (ACE)-inhibitors. For this reason, we have decided to ascertain whether hexarelin, ghrelin and other synthetic GHS can modify the catalytic activity of serum and tissue ACE in rats and humans.
1849
1850Briefly, 10 ul of serum or tissue homogenate were incubated in presence of hippuryl-histidyl-leucine, a substrate of ACE that is cleaved to histidyl-leucine. The cleavage of the substrate was quantified by measuring the fluorescence at 365/495 nm (excitation/emission) in presence of orthophthaldialdehyde. Enalapril was chosen as reference ACE-inhibitor.
1851
1852Hexarelin (1 to 100 uM) dose-dependently blunted ACE activity up to about 50% in rat and human plasma and rat lung, heart and kidney. Enalapril (0.1 to 5 uM) dose-dependently inhibited ACE activity in serum and tissues up to 85%. Ghrelin (1 to 100 uM) did not significantly modify serum and tissue ACE activity at all the concentrations tested, whereas other synthetic GHS-R1a ligands demonstrated a dose-dependent inhibition of ACE activity ranging from 10 to 85%.
1853
1854We conclude that the protective actions of certain GHS on the cardiovascular system might be mediated, at least in part, by the capability of these compounds to modulate the ACE activity in the general circulation and locally in tissues. Source: Characterization of a Novel Extraendocrine Action of the Growth Hormone Secretagogues: Inhibition of Angiotensin-Converting Enzyme (ACE) Activity, A Torsello, M Ravelli, E Bresciani, I Bulgarelli, L Tamiazzo, S Caporali, V Locatelli,
1855
1856Dept of Experimental Med, Univ of Milano-Bicocca, Monza, Italy; Interdepartmental Ctr for Bioinformatics Proteomics, Univ of Milano-Bicocca, Monza, Italy
1857Ghrelin (assumed GHS) increases GH signalling in muscle
1858
1859I have always maintained that GH signaling activity in muscle or autocrine/paracrine IGFs in muscle are more important then circulating systemic levels.
1860
1861Well here is support for Ghrelin (assumed the mimetics of GHRPs as well) inducing these important changes.
1862
1863Ghrelin infusion stimulated endogenous GH secretion, which peaked at t = 60 min ...Western blots performed on skeletal muscle biopsies revealed distinct STAT5 phosphorylation in all six subjects 30 min after the endogenous GH burst ...
1864
1865This investigation is also the first to document that ghrelin-induced endogenous GH release translates into Janus kinase/STAT signaling in skeletal muscle. - Ghrelin Infusion in Humans Induces Acute Insulin Resistance and Lipolysis Independent of Growth Hormone Signaling, Esben Thyssen, Diabetes, December 1, 2008; 57(12): 3205 - 3210
1866Hormonal Set-Points
1867
1868Here is evidence that there are set-points for hormones which can change based on environmental factors. It is very interesting that these environmental events can shift hormonal parameters that exhibit themselves throughout the post-shift life period.
1869
1870It is a deep but possible conjecture that we could shift hormonal set-points in general as a therapy for those with low hormonal levels perhaps by triggering a "famine state" or prolonged fast.
1871
1872Exposure to the Dutch Famine of 1944 -1945 and Shifts in Hormonal Set Points: Parathyroid Hormone, Paulus A. H. van Noord, J. Nutr. 135:3037S-3060S, December 2005
1873
1874BACKGROUND: Exposure to the 1944–1945 Dutch famine was shown to be associated with increased levels of androgens, estrogens, and insulin-like growth factor later in life, hormones under control of the pituitary luteinizing hormone/follicle stimulating hormone and growth hormone axes. Moreover, exposed women were at increased risk of breast cancer.
1875
1876A neurodevelopmental set-point-shift hypothesis, proposed to consolidate these findings, predicts a mechanism of shifting in hormonal set points. In the present study, we tested whether famine exposure affects parathyroid hormone (PTH).
1877
1878STUDY DESIGN: We used data from a study on osteoporosis nested within the DOM breast cancer screening cohorts including 212 women born in 1911 to 1925 whose hormones were measured in 1980. During a subsequent screening round 2 y later, 156 women provided information about exposure to the Dutch Famine of 1944–1945, thus enabling secondary analyses.
1879
1880RESULTS: A clear univariate increase in postmenopausal PTH levels was found among women who indicated exposure to the Dutch famine. Odds ratio by extreme PTH tertiles was 1.5 (95% CI: 0.6, 3.4) for moderately exposed women and 2.3 (95% CI: 1.1, 5.2) for severely exposed women. In a regression analysis of famine exposure on PTH levels, after controlling for levels of phosphorus, calcium, calcitonin, alkaline phosphatase, and estrone; having been pregnant; parity; age at famine; age at blood donation; smoking; hormone replacement therapy use at time of blood collection; height; weight; and socioeconomic status, the independent significant contribution of PTH remained.
1881
1882CONCLUSIONS: The results corroborate the hormonal set-point hypothesis and seem to extend effects of famine exposure to hormones such as PTH, which plays a role in early bone growth as well as in osteoporosis later in life. Though PTH is not under hypothalamic or pituitary control, it is partially under ganglion control. Embryologically, the parathyroids and the adenohypophysis share a common origin from pharyngeal endodermal pouches.
1883GHRH binds to GHS-receptor & potentiates GHRP's GH releasing action!
1884
1885We have spent a lot of time in this thread discussing how GHRPs (such as GHRP-6, GHRP-2, Hexarelin & Ipamorelin) potentiate GHRH's GH releasing effect. We talk of synergy, note GHRPs somatostatin inhibition at the hypothalumus & pituitary and note that GHRPs use a different method then GHRH in changing calcium concentrations within somatotrophs (GH releasing cells in the pituitary) that lead to GH secretion.
1886
1887But now we learn that GHRH also enhances GHRP's effect on GH release by binding to the GHS-receptor (obviously in addition to binding to their own GHRH receptors) and increasing the binding strength for GHRPs when they in turn bind. In other words GHRH will partially bind to a GHS-receptor and still allow GHRPs to bind as well. In fact this arrangement likely permits a double stack of two GHRP ligands thus modulating (increasing) GHRPs action.
1888
1889The study uses Ghrelin but the peptides should behave identically. However the non-peptide mimetics may not.
1890
1891From the CONCLUSION of Growth hormone-releasing hormone as an agonist of the ghrelin receptor GHS-R1a ,Felipe F. Casanuevaa, PNAS December 23, 2008 vol. 105 no. 51
1892
1893In the present study, we provide the first evidence that GHRH specifically binds to the ghrelin receptor GHS-R1a, increasing the binding capacity of its natural ligand. This binding activates the signaling route of inositol phosphate, leading to an intracellular calcium rise, and finally leads to a GHRH-mediated ghrelin receptor endocytosis. Furthermore, GHRH augments the maximal response to ghrelin in respect to inositol phosphates turnover through Gq-associated signal transduction that increases the potency of ghrelin, at least on intracellular calcium rise. ...
1894
1895Thus, GHRH is able to bind to the ghrelin receptor and does not compete for binding against ghrelin. Instead, GHRH increases the affinity of ghrelin, displaying positive binding cooperativity. Furthermore, GHRH increased the maximal response to ghrelin with respect to inositol phosphates turnover through Gq-associated signal transduction. This is in accordance with the concept of GHRH being an allosteric modulator (28, 29). This enhancer function is further supported by the fact that GHRH decreased the EC50 for ghrelin, at least as measured in the calcium assay. ...
1896
1897Finally, and quite remarkably, GHRH activated the endocytosis of the ghrelin receptor. The GHRH/GHSR1a complex progressively disappears from the plasma membrane after 20 minutes exposure to GHRH and accumulates in the perinuclear region after 60 minutes. This observation fits in well with the kinetics of receptor endocytosis described for ghrelin in the present and previous works (27). ...
1898
1899With regard to molecular mechanisms, it is not possible from the present data to establish a model of GHRH action on the ghrelin receptor. A homodimeric model was recently proposed for the ghrelin receptor, in which, because of negative cooperativity, the binding of ghrelin occurs only in one subunit, preventing another ghrelin molecule from binding to the other subunit (32). On the basis of this model, we suggest that GHRH might be able to bind in a multivalent form. When GHRH is present alone, it might bind to one subunit of the dimeric receptor interacting with the orthosteric site (main ghrelin binding site) that determines the agonist properties. However, when ghrelin is also present, GHRH occupies an ‘‘allosteric site,’’ acting as co-agonist that stabilizes the ghrelin binding. This implies that GHRH allows two ghrelin molecules to bind at the same time in the two subunits, which might explain the increase in ghrelin binding capacity observed in the present study.
1900A Couple of quick notes:
1901
1902    Beware taking MTII with CJC-1295/GHRP-6 seems to prolong and intensify nausea. (Sample of two at the moment... one of them being me.)
1903
1904    Beware GHRP-6 (assume all GHRPs) has been shown conclusively to increase gastic motility & "accelerate gastric emptying of solids ...through activation of GHS receptors, possibly located on local cholinergic enteric nerves" (Sample various effects from different people) *
1905
1906    Beware that as part of the gastric response, "GHRP-6 enhances neural contractile responses, partially via interaction with the motilin receptor on noncholinergic nerves with tachykinins as mediator, and partially via another receptor that may be a GHS-R subtype on cholinergic nerves that corelease tachykinins." (Sample at least two reports, occurs from time to time) **
1907
1908    Exogenic GH when administered every 3 hours does not inhibit pulsation.
1909
1910The reason this is interesting is that it may be possible to dose say 2iu of synthetic GH every 3 hours with mod GRF(1-29)/GHRP-6 taken say 10 minutes prior. This could be done up to six times a day.
1911
1912Alternatively 2iu of GH could be alternated with mod GRF(1-29)/GHRP-6.
1913
1914The key has to be strict adherence to a schedule or else synthetic GH will inhibit natural GH.
1915
1916It is just interesting to think about.
1917
1918    - Gastric motor effects of peptide and non-peptide ghrelin agonists in mice in vivo and in vitro, T Kitazawa, Gut 2005 54;1078-1084
1919
1920** - Interaction of the Growth Hormone-Releasing Peptides Ghrelin and Growth Hormone-Releasing Peptide-6 with the Motilin Receptor in the Rabbit Gastric Antrum, Inge Depoortere, The Journal Of Pharmacology And Experimental Therapeutics Vol. 305, No. 2
1921GHRH & GHRP-2 and GH mRNA & GH-R mRNA
1922
1923The following is the majority of the discussion from, EXPERIMENTAL STUDY - Effect of GHRH and GHRP-2 treatment in vitro on GH secretion and levels of GH, pituitary transcription factor-1, GHRH-receptor, GH-secretagogue-receptor and somatostatin receptor mRNAs in ovine pituitary cells, Ming Yan, Maria Hernandez, Ruwei Xu and Chen Chen, European Journal of Endocrinology (2004) 150 235–242
1924
1925Its a long read, but I posted it in full because it references relevant in vivo studies as well as their own findings to give us a picture of precisely how GHRH & GHRP-2 effect GH mRNA levels. The timing is interesting...
1926
1927Note that Sermorelin's half-life comes up a little short....as perhaps 10 minutes is needed.
1928
1929Solution? - maybe inject Sermorelin & GHRP-6 together, wait 6 minutes and inject another bit of Sermorelin.
1930
1931Solution? - modify Sermorelin at the 2nd position (swap alanine for D-alanine)
1932
1933The relevant timing points are highlighted below. As we would expect the combined GHRH (serum made GHRH longer-lasting) + GHRP-2 had the largest impact.
1934
1935Of interest, GH-receptor mRNA is increased by GHRH immediately as is the GH ligand so it seems that synthesis of GH-receptor triggers early GH release. This point is very interesting to me.
1936
1937Discussion ... Pituitary GH secretion is, to a large extent, controlled by three regulatory hormones: GHRH, GHS and SRIF. Each binds to G-protein-coupled membrane receptors through which intracellular signalling systems are activated (1). GHRH and GHRP administration potently increases GH secretion and this is not altered by gender, adiposity or age (9). However, peripheral circulating GHRH levels are not usually linked to an increase in GH levels as evidenced in patients with hypothalamic GHRH-secreting tumors (33). The key cell type in the regulation of GH levels is the pituitary somatotrope, which determines the amount of GH secreted in response to hypothalamic GHRH stimulation. Combined GHRH and GHRP treatment plays an important role clinically, however, the data on the mechanism of GHRH/GHRH-R and GHRP/GHS-R action are controversial (19–21). The differences may relate to the duration of GHRH and GHRP treatment and cell culture conditions as well as animal age.
1938
1939In this study, we investigated the mechanism of action of GHRH/GHRP using primary cultures of ovine pituitary cells treated with GHRH and GHRP-2 in vitro. The present study carefully investigated the concentration and duration of GHRH and GHRP treatment using 0.5, 1, 1.5 and 2 h time points and serum-free incubation conditions for cell culture to clarify the mechanism of GHRH/GHRH-R and GHRP/GHS-R action. Treatments with 10nM GHRH and 100nM GHRP-2 for 0.5, 1, 1.5 and 2 h were chosen in this study to investigate short- to mid-term changes in somatotropes. GHRH at 1.0 mg/kg (i.v.) in vivo maximally stimulated GH secretion at 15–45 min, with GH levels returning to baseline by 90–120 min after GHRH injection in humans (34). GHRP-2, GHRP-6, hexarelin or non-peptidyl GHRP mimetic compound (L-692, 429) treatment rapidly increases serum GH concentrations within 5–15 min, with the peak GH concentration usually observed 15–30 min after intravenous injection in humans (35, 36). The presence of serum in the culture medium maintains basal levels of the GHRH receptor and is important in long-term GHRH treatment (20). However, the biological half-life of GHRH 1–44 is about 3–6 min in vivo (37) as GHRH is rapidly inactivated by a plasma dipeptidyl aminopeptidase, producing a more stable metabolite, GHRH 3–44, which is about 1000 times less potent than the parent compound (37). The culture of ovine pituitary cells in serum-free culture conditions, as employed in this study, overcomes the quick degradation of GHRH and allows subsequent stimulatory GHRH and GHRP treatments to be performed under defined conditions (38).
1940
1941GHRH and GHRP treatment for 15 and 30 min rapidly stimulates maximal GH release (34–36).Furthermore, GHRH treatment for as little as 10 min rapidly increased GH transcription rate by 200–300% in primary cultured pituitary cells (39, 40). To analyse the transcription regulation of GH, we examined GH mRNA levels in response to GHRH and GHRP-2. Our results show that treatment with GHRH, GHRP-2 and combinations of GHRH and GHRP-2 increased GH mRNA expression and GH release 0.5, 1.0, 1.5 and 2 h after treatment, in a time-dependent manner. The level of GH mRNA 0.5, 1, 1.5 and 2 h after treatment was greatest in the combined GHRH and GHRP- 2 treatment group rather than in the GHRH or GHRP-2 alone treatment groups. Our results are consistent with early reports that 10nM GHRH treatment of rat pituitary cells in serum-free medium increased GH mRNA expression by 1.8- and almost 2.0-fold at 0.5 and 1 h respectively (40). This demonstrates that the effects of GHRH, GHRP-2 and combinations of GHRH and GHRP-2 on GH mRNA expression are rapid and occur at GH gene transcription level (40).
1942
1943GHRH and GHRP bind to their specific receptors on the membranes of somatotropes (37). GHRH stimulates GH synthesis by increasing the transcription rate of the GH gene and consequently GH release (40, 41). GHRP-2 enhances pituitary GH gene expression and directly stimulates GH release (42). Our results show that the duration of GHRH or GHRP-2 treatment influences the effects on the corresponding receptor mRNA expression and GH release. GHRH and GHRP treatment for 1.5 h reduces their own receptor mRNA levels. These results are consistent with previous reports which suggest that GHRH in the short-term suppresses its own receptor expression (8, 20). Surprisingly, in this experiment, the short-term GHRH or GHRP treatment (0.5 h) significantly increased the expression of ligand-specific receptor mRNAs, and also increased GH release from ovine pituitary cells. This suggests that GHRH-R or GHS-R mRNA expression may contribute to the increase in GH secretion. GHRH treatment does not significantly influence the mRNA level of GHS-R, nor does GHRP-2 change GHRH-R expression with short-term treatment. The results supported our previous report suggesting that GHRP-2 does not act through the GHRH receptor (6). It is worth mentioning that another study indicated that GHRH, at any dose tested, did not affect GHS-R levels in vitro (8).
1944
1945GH expression is mainly controlled by Pit-1, a member of the homobox POU (representing a homeodomainprotein family of which the founder members are Pit-1, Oct 1/2 and Unc-86) family of DNA-binding proteins, and GHRH and GHRP-2 elicit a time-dependent activation of Pit-1 expression by anterior pituitary cells (1, 35). Our results indicate that with combined GHRH and GHRP-2 treatment, Pit-1 mRNA expression is increased to 150, 121 and 168% at 0.5, 1.5 and 2 h after treatment respectively. GHRH enhances the levels of Pit-1 mRNA expression 0.5, 1, 1.5 and 2 h after treatment. GHRP-2 also significantly increases the levels of Pit-1 mRNA 0.5 and 2 h after treatment. GHRH and GHRP-2 may activate Pit-1 transcription and stimulates GH expression in pituitary cells through mediation of protein kinase C (PKC), mitogen-activated protein (MAP) kinase and PKA activation (1, 13, 14, 43).
1946
1947Somatostatin binds to a family of specific receptors and inhibits adenylyl cyclase via Gi proteins, and inhibits GH release but not its biosynthesis (44). In addition, somatostatin may potentially play (dual) inhibitory and stimulatory roles in controlling GH secretion by acting on two distinct somatotrope cell populations in the porcine pituitary (45). Five somatostatin receptor subtypes have been cloned and characterized and their expression is regulated in a subtype and tissue-specific manner (46–48). The results of GHRH action on sst receptor synthesis shows that, in vivo, a 4 h GHRH infusion and, in vitro, a 4 h 10nM GHRH treatment of rat pituitary cells increased sst-1 and sst-2 mRNA levels but decreased sst-5 mRNA levels (26). In the current study, 10 nM GHRH treatment increased sst-1 mRNA expression 0.5 to 2 h after the treatment. Although GHRH also increased sst-2 mRNA expression this was not statistically significant. This suggests that the acute direct regulatory action of GHRH on the synthesis of sst-1 and sst-2 receptor subtypes may be time-dependent. GHRH increased sst-1 mRNA expression may be partially due to GHRH-induced increases in Pit-1 mRNA, which activates pituitary sst-1 mRNA expression (14, 49). In contrast, 100nM GHRP-2 reduced sst-1 and sst-2 mRNA expression 0.5 to 2 h after treatment. GHRP has been suggested to act as a functional SRIF antagonist (11). Inhibition of the SRIF receptors including sst-1 and sst-2 by GHRP-2 supports this view.
1948
1949In summary, the results of this study indicate that GHRH and GHRP-2 are important mediators regulating GH, GHRH-R, GHS-R, Pit-1, sst-1 and sst-2 mRNA expression, and GH synthesis. Effects on somatotropes manifest as either a priming or an inhibitory modification of the cells, leading to increased or decreased GH secretion. Moreover, the results demonstrate that GHRH and GHRP regulate their receptor synthesis and GH release in a time-dependent manner. This study represents an essential step forward in understanding the influence of GHRH and GHRP on somatotropes. Application of this understanding may aid the development of new GHSs with high efficacy.
1950
1951Selected References
1952
195337 Frohman LA & Kineman RD. Growth hormone-releasing hormone and pituitary somatotrope proliferation. Minerva Endocrinology 2002 27 277–285.
1954
195538 Gick GG, Zeytin FN, Brazeau P, Ling NC, Esch FS & Bancroft C. Growth hormone-releasing factor regulates growth hormone mRNA in primary cultures of rat pituitary cells. PNAS 1984 81 1553–1555.
1956
195739 Barinaga M, Yamonoto G, Rivier C, Vale W, Evans R & Rosenfeld MG. Transcription regulation of growth hormone gene expression by growth hormone-releasing factor. Nature 1983 306 84–85.
1958
195940 Barinaga M, Bilezikjian LM, Vale WW, Rosenfeld MG & Evans RM. Independent effects of growth hormone releasing factor on growth hormone release and gene transcription. Nature 1985 314 279–281.
1960
19618 Kineman RD, Kamegai J & Frohman LA. Growth hormone (GH)- releasing hormone (GHRH) and the GH secretagogue (GHS), L692,585, differentially modulate rat pituitary GHS receptor and GHRH receptor messenger ribonucleic acid levels. Endocrinology 1999 140 3581–3586.
1962
196320 Lasko CM, Korytko AI, Wehrenberg WB & Cuttler L. Differential GH-releasing hormone regulation of GHRH receptor mRNA expression in the rat pituitary. American Journal of Physiology 2001 280 E626–631.
1964Insulin, how it works and why GH isn't anabolic w/o it
1965
1966I am tired of seeing the same wrong explanations on why insulin & growth hormone are anabolic so lets take a look. I don't feel like writing an article so I'll just borrow from a couple of sources.
1967
1968Insulin physiology
1969
1970It is often stated that the primary benefit of insulin in bodybuilding is that it increases the uptake of glucose into muscle and further that this movement of glucose is insulin dependent. But that is not exactly true. It may not be widely known but it is clearly established that insulin is NOT needed for glucose uptake and utilisation in man and therefore glucose uptake is NOT insulin dependent.
1971
1972There is a sufficient population of glucose transporters in all cell membranes at all times to ensure enough glucose uptake to satisfy the cell’s respiration, even in the absence of insulin. Insulin can and does increase the number of these transporters in some cells but glucose uptake is never truly insulin dependent.
1973
1974Stimulatory & Inhibiting actions
1975
1976Through stimulating the translocation or movement of 'Glut 4' glucose transporters from the cytoplasm of muscle and adipose tissue to the cell membrane insulin increases the rate of glucose uptake to values greater than the uptake that takes place in the basal state without insulin.
1977
1978When insulin is administered to people with diabetes who are fasting, blood glucose concentration falls. It is generally assumed that this is because insulin increases glucose uptake into tissues, particularly muscle. In fact this is NOT the case and is another error arising from extrapolating from in vitro rat data. It has been shown quite unequivocally that insulin at concentrations that are within the normal physiological range lowers blood glucose through inhibiting hepatic glucose production without stimulating peripheral glucose uptake. As hepatic glucose output is 'switched off' by the inhibiting action of insulin, glucose concentration falls and glucose uptake actually decreases. Contrary to most textbooks and previous teaching, glucose uptake is therefore actually increased in uncontrolled diabetes and decreased by insulin administration.
1979
1980When insulin is given to patients with uncontrolled diabetes it switches off a number of metabolic processes (lipolysis, proteolysis, ketogenesis and gluconeogenesis) by a similar inhibiting action. The result is that free fatty acid (FFA) concentrations fall effectively to zero within minutes and ketogenesis inevitably stops through lack of substrate. It takes a while for the ketones to clear from the circulation, as the 'body load' is massive as they are water and fat soluble and distribute within body water and body fat. Since both ketones and FFA compete with glucose as energy substrate at the point of entry of substrates into the Krebs cycle,glucose metabolism increases inevitably as FFA and ketone levels fall (despite the concomitant fall in plasma glucose concentration).
1981
1982Thus insulin increases glucose metabolism more through reducing FFA and ketone levels than it does through recruiting more glucose transporters into the muscle cell membrane.
1983
1984NOTE: The above was taken from:
1985
1986Mechanism of action of insulin in diabetic patients: a dose-related effect on glucose production and utilisation, Brown P, Tompkins C, Juul S & Sonksen PH, British Medical Journal 1978 1239–1242.
1987
1988Anabolic effect
1989
1990Through facilitating glucose entry into cells in amounts greater than needed for cellular respiration insulin will stimulate glycogen formation.
1991
1992It is possible to increase muscle bulk and performance not only through increasing muscle glycogen stores on a "chronic" basis but also to increase muscle bulk through inhibition of muscle protein breakdown. Just as insulin has an inhibiting action in inhibiting glucose breakdown in muscle glycogen, it also has an equally important inhibiting action in inhibitingprotein breakdown.
1993
1994The evidence now indicates that insulin does NOT stimulate protein synthesis directly (this process is under the control of growth hormone (GH) and insulin-like growth factor-I (IGF-I)). It has long been known that insulin-treated patients with diabetes have an increase in lean body mass when compared with matched controls. This results from insulin's inhibition ofprotein breakdown in muscle tissue.
1995
1996Growth Hormone Anabolic Actions
1997
1998GH’s major action is to stimulate protein synthesis. It is at least as powerful as testosterone in this effect and, as they both operate through distinct pathways, their individual effects are additive or possibly even synergistic. In addition to stimulating protein synthesis, GH simultaneously mobilises fat by a direct lipolytic action. Together, these two effects are responsible for the 'partitioning' action of GH whereby it diverts nutritional calories toprotein synthesis, possibly through using the energy derived from its lipolytic action. It most likely stimulates protein synthesis through mobilisation of amino acid transporters in a manner analogous to insulin and glucose transporters.
1999
2000IGF-I also acts directly to stimulate protein synthesis but it has a weaker lipolytic action. GH, IGF-I and insulin thus act in concert to stimulate protein synthesis.
2001
2002GH and IGF-I act in a promoting manner to stimulate protein synthesis while insulin acts in its characteristic inhibiting manner to inhibit protein breakdown. Thus they are synergistic in their powerful anabolic action.
2003
2004Insulin is essential for the anabolic action of GH. GH administration in the absence of adequate insulin reserves (as during fasting or in Type 1 diabetes) is in fact catabolic and its lipolytic and ketogenic properties can induce diabetic ketoacidosis. Thus GH and insulin are closely linked in normal physiology and it is of great interest to see that athletes have discovered ways in which this normal physiological dependence can be exploited to enhance performance.
2005
2006NOTE: The above was "lifted" with little change from parts of:
2007
2008HORMONES AND SPORT: Insulin, growth hormone and sport, P H Sonksen, Journal of Endocrinology (2001) 170, 13–25
2009Boosting Insulin Naturally
2010
2011I understand not wanting to use exogenously administered insulin. Does this mean you would lose out on insulin's contribution to GH induced anabolism?
2012
2013No...you can achieve what would amount to a couple iu of Hum-R by using glucose & leucine. The two work synergistically to spike insulin.
2014
2015About 3.5 grams of Leucine was sufficient to double the insulin response to 25grams of glucose. See below:
2016
2017Leucine, when ingested with glucose, synergistically stimulates insulin secretion and lowers blood glucose, Dionysia Kalogeropoulou, Metabolism Clinical and Experimental 57 (2008) 1747–1752
2018
2019Thereafter, they received 25 g glucose or 1 mmol/kg lean body mass leucine or 1 mmol/kg lean body mass leucine plus 25 g glucose in random order. Serum leucine, glucose, insulin, glucagon, and alpha-amino nitrogen concentrations were measured at various times during a 2.5-hour period after ingestion of the test meal. The amount of leucine provided was equivalent to that present in a high-protein meal, that is, that approximately present in a 350-g steak. After leucine ingestion, the leucine concentration increased 7-fold; and the alpha-amino nitrogen concentration increased by 16%. Ingested leucine did not affect the serum glucose concentration. When leucine was ingested with glucose, it reduced the 2.5-hour glucose area response by 50%. Leucine, when ingested alone, increased the serum insulin area response modestly. However, it increased the insulin area response to glucose by an additional 66%; that is, it almost doubled the response. Ingested leucine stimulated an increase in glucagon. Ingested glucose decreased it. When ingested together, the net effect was essentially no change in glucagon area. In summary, leucine at a dose equivalent to that present in a highprotein meal, had little effect on serum glucose or insulin concentrations but did increase the glucagon concentration. When leucine was ingested with glucose, it attenuated the serum glucose response and strongly stimulated additional insulin secretion. Leucine also attenuated the decrease in glucagon expected when glucose alone is ingested. The data suggest that a rise in glucose concentration is necessary for leucine to stimulate significant insulin secretion. This in turn reduces the glucose response to ingested glucose.
2020Here is the Insulin Cheat Sheet I put together in September
2021
2022The following was a nice little concise summation of the effect insulin has on GH, GHRs and intracellular events, put together about 6 months back. It was designed to be a pointer to the primary studies that demonstrate each point.
2023
2024It might be of use to someone so I post it here today:
2025
2026INSULIN CODEX - I
2027
2028Many factors are known to regulate the responsiveness of the growth hormone receptor (GHR) to growth hormone (GH). The most important are insulin, thyroid [SEE: THYROID HORMONES CODEX] and sex hormones [SEE: ESTROGEN CODEX & TESTOSTEONE CODEX].
2029
2030The growth-promoting action of GH is mediated by IGF-I which is produced mainly in the liver, but also in extrahepatic tissues. There is strong evidence that the anabolic action of GH requires the presence of insulin and adequate nutrition. This is exemplified in type 1 diabetes where IGF-I levels are low and longitudinal growth is impaired despite high serum levels of GH [1, 2]. These abnormalities are corrected by insulin treatment [3, 4].
2031
2032Insulin's effect on GHR expression
2033
2034The effects of insulin on GHR expression and function are tissue specific.
2035
2036In cultures of rat hepatoma cells, insulin increases GHRs [5]. In animal studies, insulin deficiency results in a decrease of GH binding and GHR expression in liver [6, 7], which can be reversed by insulin administration [6, 8]. In extra-hepatic tissues such as bone and kidney, there is evidence that insulin down-regulates GHRs [9, 6–8].
2037
2038It is well established that surface membrane receptors are dynamically regulated, with cell surface abundance representing the net balance of "recycling of internalised receptors" and translocation of newly synthesized receptors to the cell membrane.
2039
2040There is recent evidence that the surface translocation of GH receptors is inhibited by insulin.
2041
2042Insulin dose-dependently stimulates liver GHR synthesis and GH binding, however increasing insulin concentrations reduce GHR surface translocation, which overcomes the effect on receptor synthesis [5].
2043
2044These findings show that the mechanism by which insulin regulates tissue responsiveness to GH is complex and in part mediated by effects on GHR expression and surface translocation.
2045
2046Decrease in receptor surface availability with high dose insulin may represent rapid mechanism for insulin regulation of the GHR function.
2047
2048In human studies, there is also evidence that insulin modulates the expression of GHRs. This is based on measurement of circulatory levels of GHBP. As GHBP is derived from proteolytic cleavage of the extracellular domain of the GH receptor, change in GHBP levels may reflect GH receptor status [10].
2049
2050Thus when insulin levels are low, high levels of GH does not translate into a rise in circulating IGF-I [11-17]. In type I diabetes, GHBP levels are low and associates with low IGF-I levels [18]. These investigations have also observed a significant positive correlation between levels of GHBP and total insulin dose, suggesting that GHR status in humans is dependent on adequate insulinisation [18].
2051
2052Insulin's effect on GH receptor signaling
2053
2054There is strong evidence that insulin modulates GHR signaling in addition to the effects on receptor expression and surface translocation.
2055
2056In rat hepatoma cells, low dose insulin administration results in GH-induced stimulation of JAK2 phosphorylation however high dose insulin treatment results in inhibitory effect [5, 19].
2057
2058The effect of insulin on GHR function appears to be mediated by the PI-3 kinase and MAPK/ERK pathways [5, 20, 21]. It has been shown that insulin increases GH signaling by enhancing GH-induced activation of MAPK/ERK pathway through post signalling cross-talk [21].
2059
2060In human muscle, in vivo, ERK1/2 phosphorylation was increased by insulin, but insulin per se did not induce phosphorylation of Stat5. [22]
2061
2062Overall Summation
2063
2064Insulin regulates GHR expression, translocation and GHR function. The regulation of GH receptor expression is complex and tissue dependent. Insulin stimulates hepatic GHR synthesis and GH binding but down-regulates GHR expression in kidney and bone tissue.
2065
2066In liver, high concentrations of insulin reduce GHR surface translocation, in such a way as to regulate receptor surface availability.
2067
2068The effects of insulin on GHR function are mediated by stimulation of GH-induced JAK2 phosphorylation, PI-3 kinase and MAPK/ERK pathways.
2069
2070SOURCES: 1 - Horner JM, Kemp SF, Hintz RL. Growth hormone and somatomedin in insulin-dependent diabetes mellitus. J Clin Endocrinol Metab. 1981;53:1148–53.
2071
20722 - Tan K, Baxter RC. Serum insulin-like growth factor I levels in adult diabetic patients: the effect of age. J Clin Endocrinol Metab. 1986;63:651–5.
2073
20743 - Vigneri R, Squatrito S, Pezzino V, Filetti S, Branca S, Polosa P. Growth hormone levels in diabetes. Correlation with the clinical control of the disease. Diabetes. 1976;25:167–72.
2075
20764 - Amiel SA, Sherwin RS, Hintz RL, Gertner JM, Press CM, Tamborlane WV. Effect of diabetes and its control on insulin-like growth factors in the young subject with type I diabetes. Diabetes. 1984;33:1175–9.
2077
20785 - Leung KC, Doyle N, Ballesteros M, Waters MJ, Ho KK. Insulin regulation of human hepatic growth hormone receptors: divergent effects on biosynthesis and surface translocation. J Clin Endocrinol Metab. 2000;85:4712–20.
2079
20806 - Baxter RC, Bryson JM, Turtle JR. Somatogenic receptors of rat liver: regulation by insulin. Endocrinology. 1980;107:1176– 81.
2081
20827 - Menon RK, Stephan DA, Rao RH, Shen-Orr Z, Downs LS Jr, Roberts CT Jr, et al. Tissue-specific regulation of the growth hormone receptor gene in streptozocin-induced diabetes in the rat. J Endocrinol. 1994;142:453–62.
2083
20848 - Maes M, Ketelslegers JM, Underwood LE. Low plasma somatomedin-C in streptozotocin-induced diabetes mellitus. Correlation with changes in somatogenic and lactogenic liver binding sites. Diabetes. 1983;32:1060–9.
2085
20869 - Flyvbjerg A, Bennett WF, Rasch R, Kopchick JJ, Scarlett JA. Inhibitory effect of a growth hormone receptor antagonist (G120K-PEG) on renal enlargement, glomerular hypertrophy, and urinary albumin excretion in experimental diabetes in mice. Diabetes. 1999;48:377–82.
2087
208810 - Baumann G. Growth hormone binding protein 2001. J Pediatr Endocrinol Metab. 2001;14:355–75.
2089
209011 - Ho KY, Veldhuis JD, Johnson ML, Furlanetto R, Evans WS, Alberti KG, et al. Fasting enhances growth hormone secretion and amplifies the complex rhythms of growth hormone secretion in man. J Clin Invest. 1988;81:968–75.
2091
209212 - Hartman ML, Veldhuis JD, Johnson ML, Lee MM, Alberti KG, Samojlik E, et al. Augmented growth hormone (GH) secretory burst frequency and amplitude mediate enhanced GH secretion during a two-day fast in normal men. J Clin Endocrinol Metab. 1992;74:757–65.
2093
209413 - Baxter RC, Bryson JM, Turtle JR. The effect of fasting on liver receptors for prolactin and growth hormone. Metabolism. 1981;30:1086–90.
2095
209614 - Maes M, Underwood LE, Ketelslegers JM. Low serum somatomedin-C in protein deficiency: relationship with changes in liver somatogenic and lactogenic binding sites. Mol Cell Endocrinol. 1984;37:301–9.
2097
209815 - Thissen JP, Triest S, Maes M, Underwood LE, Ketelslegers JM. The decreased plasma concentration of insulin-like growth factor-I in protein-restricted rats is not due to decreased numbers of growth hormone receptors on isolated hepatocytes. J Endocrinol. 1990;124:159–65.
2099
210016 - Ohashi S, Kaji H, Abe H, Chihara K. Effect of fasting and growth hormone (GH) administration on GH receptor (GHR) messenger ribonucleic acid (mRNA) and GH-bindingprotein (GHBP) mRNA levels in male rats. Life Sci. 1995;57:1655–66.
2101
210217 - Maccario M, Aimaretti G, Grottoli S, Gauna C, Tassone F, Corneli G, et al. Effects of 36 hour fasting on GH/IGF-I axis and metabolic parameters in patients with simple obesity. Comparison with normal subjects and hypopituitary patients with severe GH deficiency. Int J Obes Relat Metab Disord. 2001;25:1233–9.
2103
210418 - Kratzsch J, Keliner K, Zilkens T, Schmidt-Gayk H, Selisko T, Scholz GH. Growth hormone-binding protein related immunoreactivity is regulated by the degree of insulinopenia in diabetes mellitus. Clin Endocrinol (Oxf). 1996;44:673–8.
2105
210619 - Ji S, Guan R, Frank SJ, Messina JL. Insulin inhibits growth hormone signaling via the growth hormone receptor/JAK2/ STAT5B pathway. J Biol Chem. 1999;274:13434–42.
2107
210820 - Bennett WL, Keeton AB, Ji S, Xu J, Messina JL. Insulin regulation of growth hormone receptor gene expression: involvement of both the PI-3 kinase and MEK/ERK signaling pathways. Endocrine. 2007;32:219–26.
2109
211021 - Xu J, Keeton AB, Franklin JL, Li X, Venable DY, Frank SJ, et al. Insulin enhances growth hormone induction of the MEK/ERK signaling pathway. J Biol Chem. 2006;281:982–92.
2111
211222 - Growth Hormone Signaling in Vivo in Human Muscle and Adipose Tissue: Impact of Insulin, Substrate Background, and Growth Hormone Receptor Blockade, Charlotte Nielsen, et al., The Journal of Clinical Endocrinology & Metabolism July 2008 Vol. 93, No. 7 2842-2850
2113Protein Metabolism - The complementary role of various hormones in inducing Anabolism
2114
2115Too many people have very little idea how the following factors work together in increasing proteinsynthesis and preventing protein breakdown. If they truly understood these things would they give up seeking THE magic bullet? I doubt it... Would they stop seeking out self-proclaimed gurus who in my opinion fail miserably in understanding these things themselves.
2116
2117• Insulin • Growth Hormone • Amino Acid Pool • Exercise • Blood Flow • IGF-1 • IGF-1/IGFBP-3 • Androgens • Thyroid Hormones
2118
2119What follows are basically my notes structured in such a way as to be highly readable, massively informative and well referenced for further research should someone be so inclined.
2120
2121I didn't really intend to post this for public consumption so forgive the format. I ask that you not cut and paste this post onto other forums. Basically it is here for anyone who reads this thread and no one else.
2122
2123The following post was derived both generally and specifically from the following studies. Additional studies are provided as references for selective material herein.
2124
2125An abundant supply of amino acids enhances the metabolic effect of exercise on muscle protein, Gianni Biolo, Am. J. Physiol. 273 (Endocrinol. Metab. 36): El22-E129, 1997.
2126
2127Acute Growth Hormone Effects on Amino Acid and Lipid Metabolism, K. C. Copeland,Journal of Clinical Endocrinology and Metabolism Vol. 78, No. 5 1994
2128
2129Effects of Insulin-Like Growth Factor-1/Binding protein-3 Complex on Muscle Atrophy in Rats, Martin M. Zdanowicz, 2003 by the Society for Experimental Biology and Medicine
2130
2131Hormonal regulation of human protein metabolism, Pierpaolo De Feo, Eur J Endocrinol 1996:135:7-18
2132
2133Physiologic Hyperinsulinemia Stimulates protein Synthesis and Enhances Transport of Selected Amino Acids in Human Skeletal Muscle, Gianni Biolo, J. Clin. Invest. vol. 95, 811 - 819
2134
2135Skeletal muscle protein anabolic response to resistance exercise and essential amino acids is delayed with aging, Micah J. Drummond, J Appl Physiol 104: 1452-1461, 2008
2136
2137Compartmental model of leucine kinetics in humans, Claudio Cobelli, Am. J. Physiol. 261 (Endocrinol. Metab. 24): E539-E550, 1991
2138
2139Dose-response curves of effects of insulin on leucine kinetics in humans, Paolo Tessari, Am. J. Physiol. 251 (Endocrinol. Metab. 14): E334-E342, 1986.
2140
2141Growth hormone decreases muscle glutamine production and stimulates proteinsynthesis in hypercatabolic patients, Gianni Biolo, Am J Physiol Endocrinol Metab 279:323-332, 2000
2142
2143Increased rates of muscle protein turnover and amino acid transport after resistance exercise in humans, Gianni Biolo, Am. J. Physiol. 268 (Endocrinol. Metab. 31): E514-E520, 1995.
2144
2145Insulin action on protein metabolism in acromegalic patients, Alberto Battezzati, Am J Physiol Endocrinol Metab 284:823-829, 2003
2146
2147Leucine and phenylalanine kinetics during mixed meal ingestion a multiple tracer approach, Gianni Biolo, Am. J. Physiol. 262 (Endocrinol. Metab. 25): E455-E463,1992.
2148
2149protein synthesis and breakdown in skin and muscle a leg model of amino acid kinetics, Gianni Biolo, Am. J. Physiol. 267 (Endocrinol. Metab. 30): E467-E474, 1994.
2150
2151Transmembrane transport and intracellular kinetics of amino acids in human skeletal muscle, Gianni Biolo, Am. J. Physiol. 268 (Endocrinol. Metab. 31): E75-E84, 1995.
2152
2153Insulin
2154
2155There is indirect evidence that post-prandial [after a meal] hyperinsulinemia induces protein anabolism, other than through the suppression of whole-body proteolysis [i.e. protein breakdown/ catabolism], also by facilitating the incorporation of dietary amino acids into new proteins. In fact, when post-prandial hyperinsulinemia and hyperaminoacidemia [high insulin & high amino acids] are reproduced in normal subjects by a combined intravenous infusion of insulin and amino acids, the estimates of whole-bodyprotein synthesis increase more than after amino acids alone (20).
2156
2157[Insulin + Amino Acids = greater increase in entire body proteinsynthesis] The stimulatory effect of hyperinsulinemia on whole-body protein synthesis cannot be demonstrated when insulin alone is infused (20-25). In this case, by reducing the rate of protein breakdown, hyperinsulinemia decreased the intracellular concentrations of most amino acids (26), limiting their utilization for proteinsynthesis (27).
2158
2159[In other words the store of amino acids (often called the intracellular amino acid pool) is replenished in two ways. One by eating/ingestion of protein & the other by the breakdown of protein in muscle (i.e.protein degradation). This latter, protein degradation reduces proteinto its constituent parts (amino acids) which will be transported outside the cell & either be further removed or remain in the amino acid pool (which resides between muscle cells) and is available for reuse in muscle for the next round of transport into muscle & new proteinsynthesis. Insulin reduces protein breakdown so the amino acid pools are not replenished.] Branched-chain amino acids are particularly sensitive to hyperinsulinemia (28) and it has been shown the insulin-induced suppression of plasma isoleucine concentration (29), i.e. of a single essential amino acid, is sufficient to decrease wholebody protein synthesis.
2160
2161[So in essence protein synthesis requires all the essential amino acids. If one is missing no protein synthesis will occur.]
2162
2163The results of recent studies demonstrate that the effects of insulin on whole-body protein kinetics represent the mean results of differential effects of the hormone on the rates of protein breakdown and synthesis of individual proteins. For instance, despite the rate of whole-body proteolysis being decreased by insulin (20-25), the rate of muscle protein proteolysis is not affected by local hyperinsulinemia (30). Such a differential effect can be explained by the fact that insulin decreases the proteolytic activity of lysosomes but does not control the ubiquitin system (31) that is responsible for the bulk of muscle proteolysis (31).
2164
2165[So insulin decreases protein breakdown/degradation throughout the entire body but does not inhibit protein breakdown specifically in muscle.] References:
2166
216720 - Castellino P, Luzi L, Simonson DC. Haymond M. DeFronzo RA. Effect of insulin and plasma amino acid concentrations of leucine metabolism in man: role of substrate availability on estimates of whole body protein synthesis. J Clin Invest 1987: 80:1784-9 3
2168
216921 - Fukagawa NK. Minaker KL. Rowe JW. Goodman MN. Matthews DE. Bier DM, et al. Insulin-mediated reduction of whole body protein breakdown: dose-response effects on leucine metabo¬ lism in postabsorptive men. J Clin Invest 1985:76:2306-11
2170
217122 - Tessari P, Trevisan R, Inchiostro S, Biolo G, Nosadini R, De Kreutzenberg SV, et al. Dose-response curves of effects of insulin on leucine kinetics in humans. Am J Physiol 1986;251:E334-42
2172
217323 - Tessari P. Nosadini R. Trevisan R. De Kreutzenberg SV. Inchiostro S. Duner E. et al. Defective suppression by insulin of leucine-carbon appearance and oxidation in type 1, insulin dependent diabets mellitus: evidence for insulin resistance involving glucose amino acid metabolism. J Clin Invest 1986:77:1797-804
2174
217524 - Luzi L, Castellino P. Simonson DC, Petrides AS, DeFronzo RA. Leucine metabolism in IDDM: role of insulin and substrate availability. Diabetes 1990:39:38-48
2176
217725 - De Feo P. Volpi E, Lucidi P, Cruciani G. Reboldi G. Siepi D, et al. Physiological increments in plasma insulin concentrations have selective and different effects on synthesis of hepatic proteins in normal humans. Diabetes 1993:42:995-1002
2178
217926 - Alvestrand A, DeFronzo RA, Smith D, Wahren J. Influence of hyperinsulinaemia on intracellular amino acid levels and amino acid exchange across splanchnic and leg tissues in uraemia. Clin Sci 1988;74:155-63
2180
218127 - De Feo P. Haymond MW. Effect of insulin on protein metabolism in humans: methodological and interpretative questions. Diab Nutr Metab 1991:4:241-9
2182
218328 - Fukagawa NK. Minaker KL. Young VR. Rowe JW. Insulin dosedependent reductions in plasma amino acids in man. Am J Physiol 1986;250:E13-7
2184
218529 - Lecavalier L, De Feo P. Haymond MW. Isolated hypoisoleucinemia impairs whole body but not hepatic protein synthesis in humans. Am J Physiol 1991;261:E578-86
2186
2187    Biolo G, Declan Fleming RY. Wolfe RR. Physiologic hyper¬ insulinemia stimulates proteinsynthesis and enhances trans¬ port of selected amino acids in human skeletal muscle. J Clin Invest 1995:95:811-9
2188
2189Insulin increases the amount of protein deposited in muscle by directly increasing the rate of proteinsynthesis (40-60% as measured by lysine & phenylalanine dissapearance from intracellular pools). Insulin does not increase (or regulate) transmember amino acid transport. Therefore transportation of amino acids is not a primary mediator of insulin anabolic actions in muscle.
2190
2191[So Insulin's primary modes of action are reduction of whole-bodyprotein breakdown as discussed already & in muscle an increase in the rate of protein synthesis. Now it draws on the intracellular pool of amino acids to effect this increased synthesis. It is possible to run out of amino acids from that pool. Insulin can suck the reservoir dry so to speak.
2192
2193In addition insulin in general (there is an exception) does not increase the rate of transportation of amino acids across the cell membrane into the cell. That remains normal. But the benefit of insulin in muscle is that it increases protein synthesis. However other things are needed besides insulin to effect anabolism.] Insulin draws on an existing intracellular pool of amino acids. When amino acid concentrations are maintained at levels higher than normal during systemic insulin administration insulin increased muscleprotein synthesis (40).
2194
2195[So anabolism occurs when both insulin increased protein synthesis occurs and amino acid levels are maintained higher then normal. The primary way to effect this is to increase amino acid/protein ingestion.] 40. - Bennett, W. M., A. A. Connacher, C. M. Scringeour, R. T. Jung, and M. J. Rennie. 1990. Euglycemic hyperinsulinemia augments amino acid uptake by human leg tissues during hyperaminoacidemia. Am. J. PhysioL 259:E185-E194
2196
2197Insulin does not significantly modify protein breakdown in muscle. It has been shown that, during adequate amino acid supply, the most important degradative system in muscle is an ATP-independent system that requires the presence of a specialized protein, termed ubiquitin. This system is not sensitive to insulin. Concerning protein breakdown Insulin apparently plays a role only in the regulation of the lysosome activity. These intracellular organelles are not involved in the myofibrillar protein degradation in normal conditions, but only in the presence of low insulin levels or decreased amino acid availability).
2198
2199[So again insulin will increase protein synthesis in muscle but will not inhibit protein breakdown. So in general anabolism will occur if moreprotein synthesis then protein breakdown occurs.]
2200
2201Following protein degradation, the amino acids from the degradation event are either transported outward (or in the case of leucine oxidized) or are redirected back into protein synthesis. Phenylalanine & leucine have been shown to be redirected back into protein synthesis while lysine may not.
2202
2203Insulin induces hyperpolarization in the skeletal muscle cells by directly activating the sodium ion (Na+) and potassium ion (K+) -ATPase pump. Those amino acids which are strongly "attracted" to the electrochemical characteristics of the cell membrane are more readily taken up into muscle from the intracellular pool of amino acids. Alanine & lysine are two amino acids that have this attraction and are more readily drawn into muscle by insulin.
2204
2205[When protein in muscle is broken down and its constituents removed back to the amino acid pool, those amino acids may be removed from muscle pools entirely, may be reused for new synthesis or for some amino acids oxidized or used for energy. It would not benefit anabolism to lose the important amino acid leucine to oxidation.
2206
2207Insulin which in general doesn't increase transport of amino acids from pool into cells, does so for a few amino acids which use NA+ & K+ channels, namely alanine & lysine.]
2208
2209The branched-chain amino acids (leucine, valine, and isoleucine) and the aromatic (phenylalanine and tyrosine) are preferably transported through system L . This sodium-independent system is unable to generate high transmembrane gradients for its substrates. It has been shown that the kinetic characteristics of system L are not influenced by insulin.
2210
2211[So insulin which has no effect on this mode of transport does not increase the uptake of some very important amino acids.] Blood flow has been found to increase local amino acid delivery to muscle and secondarily increase amino acid transport. This effect may be responsible for increase in leucine uptake.
2212
2213[This is an extremely important way in which amino acids are drawn to muscle and into cells. Time and again the important amino acid leucine has been shown to make its way into cells via increase in blood flow.] Alanine synthesis (which is a function of pyruvate) also increases in the presence of insulin because insulin increases glucose uptake & intracellular pyruvate in muscle.
2214
2215[Certain amino acids can be synthesized from the breakdown of other amino acids. Alanine is one of them. Alanine is often used for energy and so protein synthesis rate or anabolism may depend on the availability of alanine not yet oxidized. The fact that insulin increases alanine synthesis is a desirable effect.] The anabolic effect of insulin on muscle may have become self-limited because of an intracellular depletion of precursor amino acids for protein synthesis, unless amino acid transport is independently stimulated by other factors, i.e., amino acid administration.
2216
2217[Again an external source of amino acids is needed to make insulin anabolic in muscle.]
2218
2219    Kettlehut IC. Wing SS. Goldberg AL. Endocrine regulation of protein breakdown in skeletal muscle. Diab Metab Rev 1988;4:751-72 - - -
2220
2221Growth Hormone
2222
2223Growth hormone promotes protein anabolism with mechanisms different from insulin. It does not affect the rates of whole-body proteolysis but decreases those of amino acid oxidation (51, 52). The sparing effect on amino acid oxidation results in a greater rate of their incorporation into proteins (51-53), with a net proteinanabolic effect.
2224
2225    Horber FF. Haymond MW. Human growth hormone prevents the protein catabolic side effects of prednisone in humans. J Clin Invest 1990:86:265-72
2226
2227    Copeland KC. Nair KS. Acute growth hormone effects on amino acid and lipid metabolism. J Clin Endocrinol Metab 1994: 78:1040-7
2228
2229    Yarasheski KE. Campbell JA. Smith K, Rennie MJ, Holloszy JO, Bier DM. Effect of growth hormone and resistance exercise on muscle growth in young men. Am J Physiol 1992;262:E261-7 [So Growth Hormone decreases amino acid oxidation (or break down for energy). This should have the effect of preserving key amino acids in that very important amino acid pool. This means that muscleprotein synthesis or even increased muscle protein synthesis induced by insulin will be more prolonged because there will be a larger pool of raw material (aminos) to draw from.]
2230
2231Growth hormone decreases muscle glutamine production
2232
2233In agreement with previous observations in animals (20, 23), this study shows that rhGH infusion in traumatized patients accelerates the rates of transmembrane transport of the essential amino acids leucine and phenylalanine. This effect was independent of changes of leg blood flow and arterial amino acid concentrations. This rhGH-mediated increased ability of transmembrane systems to transport essential amino acids confirms previous observations in vitro (20, 23) and represents a novel observation in vivo.
2234
2235[So while insulin increases transport of a few aminos (alanine & lysine), GH increases amino acid transport for leucine and phenylalanine. This would mean that GH would increase transport of the other aromatic amino acid tyrosine and the other branch-chain amino acids valine and isolecine]
2236
2237Besides stimulating protein synthesis, growth hormone suppressed the rate of catabolism of the branched-chain amino acids leucine, isoleucine, and valine. This effect has been reported by several other authors using isotopic tracers of leucine at the whole body level (8, 12).
2238
2239[So growth hormone unlike insulin suppresses the breakdown and loss of branch-chain amino acids & probably all amino acids. Thus GH provides more raw material for insulin-induced higher rate of proteinsynthesis.]
2240
2241glutamine and alanine constitute the major carriers of nitrogen among body tissues (2).In skeletal muscle, these amino acids are constantly being synthesized and released into the bloodstream (2). In severe trauma, alanine release from muscle is greatly accelerated, whereas glutamine release was found to be increased or unchanged (5). Our results indicate that rhGH administration selectively decreases the rates of synthesis and release of glutamine, whereas alanine synthesis did not change during the hormone administration.
2242
2243[Growth hormone has a negative effect on glutamine synthesis.] In our patients, whole body skeletal muscle released 19 g of glutamine per day into the bloodstream before rhGH administration. After rhGH administration, glutamine release from skeletal muscle decreased by 50%, whereas at the whole body level, glutamine clearance tended to decrease by 15%.
2244
2245[So glutamine which is very important to the immune system & is urgently needed in times or severe trauma is not really made available. This in part may be the reason why death occurs in critically ill patients given GH.] The obvious solution for this potential side effect of growth hormone treatment in critically ill patients is to simultaneously administer exogenous glutamine to offset the decreased availability of the endogenous amino acid.
2246
2247[This also is a lesson for those seeking muscle anabolism while using GH. Less glutamine is synthesized and thus available in the presence of GH. Thus supplementation with glutamine should increase the potential for anabolism.]
2248
2249Amino Acid Pool
2250
2251From a dynamic point of view, such muscle hypertrophy results from changes in the rates of proteinsynthesis and/or breakdown. In addition, an acceleration of the rates of amino acid transport into muscle cells may contribute to muscle anabolism by increasing amino acid availability for protein synthesis. Studies suggest that muscle protein accretion occurs in the recovery phase after exercise rather than during the actual exercise period. The leucine tracer incorporation technique has shown that the rate of muscle protein synthesis in humans is increased after exercise (7) and remains elevated for > 24 h (7).
2252
2253In these studies, muscle protein breakdown was not ddirectly measured. However, the increase in proteinsynthesis was so large that if it were not accompanied by a concomitant increment in protein breakdown, exercise training would result in a greater increase in muscle size than actually occurs.
2254
2255    Chesley, A., J. D. MacDougall, M. A. Tarnopolsky, S. A. Atkinson, and K. Smith. Changes in human muscle protein synthesis after resistance exercise. J. AppZ. Physiol. 73: 1383- 1388,1992.
2256
2257Exercise
2258
2259We found that, after exercise, the rates of muscle protein turnover and amino acid transport were increased. protein synthesis and breakdown increased simultaneously but to a different extent. Synthesis increased by - lOO%, whereas breakdown increased by only - 50%. Consequently, protein balance (synthesis minus breakdown) improved after exercise (becoming not significantly different from zero) but did not shift to a positive value. These results suggest that physical exercise can restrain net muscleprotein catabolism but does not directly promote net protein deposition in the postabsorptive state. Thus exercise probably needs to interact with other factors, such as feeding, to promote muscle anabolism.
2260
2261[Although this paragraph is not completely clear, having read the studies I can say that the take home message is that exercise reduces catabolism. Exercise increase both breakdown & synthesis ofprotein but that exercise alone will not tilt things toward anabolism. Amino acid availability is required.] The notion that increased amino acid availability can directly regulate protein synthesis is further supported by the fact that the rate of synthesis was enhanced during amino acid infusion or in catabolic patients, in whom a large primary increase of breakdown occurs. In the present study therefore the acceleration of protein breakdown and amino acid transport may have contributed to the increase inprotein synthesis. Because of the increase in amino acid transport, the changes in protein degradation have been more than offset by the increased rate of synthesis.
2262
2263We found that, after exercise, the absolute rate of protein breakdown was accelerated. This catabolic response almost counteracted the increase in protein synthesis.
2264
2265[So exercise + amino acids = anabolism]
2266
2267Our study suggests that this mechanism may also be important for amino acid and protein metabolism. Thus physical exercise may not have a direct regulatory effect on the membrane transport systems, but its effect may be due to the increased amino acid delivery to muscle tissue secondary to the increased blood flow.
2268
2269Anabolism vs Catabolism
2270
2271The intracellular availability of amino acids may not be the sole acute regulator of muscle proteinsynthesis, inasmuch as hormones and other factors may have direct effects. Nonetheless it seems clear that the rates of breakdown and inward amino acid transport are important factors. The importance of variations in inward transport can be appreciated when the difference between the anabolic response to exercise is compared with the catabolic response to critical illness. In both circumstances, the rate of breakdown is increased, but in the case of critical illness, inward transport is relatively impaired, rather than stimulated. As a consequence, muscle synthesis is not stimulated to the same extent as breakdown, with net catabolism resulting. Thus the increase in inward transport after exercise appears to be an important response that enables synthesis to increase to a greater extent than breakdown.
2272
2273Side Note (skin more important then muscle)
2274
2275Thus the stability of muscle mass throughout the day is maintained by alternating phases of catabolism during fasting and anabolism after feeding. This process is necessary to supply liver and gut with amino acids for protein synthesis in the fasting state. Our data suggest that the same mechanism is not involved in the skin, because, after - 20 h of fasting, we did not observe any net loss of essential amino acids from this tissue. From these results, it appears that maintenance of skin mass is a high metabolic priority, and this may occur, at least in part, at the expense of muscle tissue.
2276
2277Blood flow
2278
2279Over the last decade, evidence has accumulated supporting the hypothesis that blood flow is a major regulator of glucose uptake in skeletal muscle (1).
2280
2281    Baron, A. D., H. Steinberg, G. Brechtel, and A. Johnson. Skeletal muscle blood flow independently modulates insulinmediated glucose uptake. Am. J. Physiol. 266 (Endocrinol. Metab. 29): E248-E253,1994.
2282
2283The results of our study suggest that variations in blood flow may also affect muscle protein metabolism by increasing transport of free amino acids into cells, which in turn stimulates protein synthesis. This notion is supported by the high correlation between blood flow and FSR.
2284
2285In summary, the results of our study demonstrate that net protein synthesis during amino acid administration can be doubled by previous performance of heavy resistance exercise. Moreover, the data suggest a link between the stimulation of protein synthesis after exercise and an acceleration in amino acid transport. The greater rate of transport after exercise may be due to the increase in blood flow.
2286
2287An abundant supply of amino acids enhances the metabolic effect of exercise on muscle protein, Gianni Biolo, Am. J. Physiol. 273 (Endocrinol. Metab. 36): El22-E129, 1997. [So Exercise + increased bloodflow + amino acids = increased amino acid transport. Of course this leads to the understanding that aminos need to be in the blood prior to the increased blood flow of exercise.]
2288
2289IGF-1
2290
2291The data available in humans indicate that IGF-I has a mechanism of action similar to insulin on proteinmetabolism (62-65) because IGF-I administration also reduces the rates of whole-body protein breakdown and synthesis. When compared on a molar basis, the action of IGF-I is ~ 14 times less potent than that of insulin (65),
2292
2293IGF-I might affect protein metabolism only in selected tissues through a paracrine action on whether IGF-I, due to its longer half-life could influence whole-body protein metabolism when plasma GH concentrations decline; and the role played by IGF-I binding proteins in the modulation of the endocrine action of IGF-I onprotein metabolism needs to be established.
2294
2295    Turkalj I. Keller U. Ninnis R, Vosmeer S, Stauffacher W. Effect of increasing doses of recombinant human insulin-like growth factor I on glucose, lipid and leucine metabolism in man. J Clin Endocrinol Metab 1992;75:1186-91
2296
2297    Mauras . Horber FF, Haymond MW. Low dose recombinant human insulin-like growth factor-1 fails to affect protein anabolism but inhibits islet cell secretion in humans. J Clin Endocrinol Metab 1992;75:1192-7
2298
2299    Elhay D. McAloon-Dyke M. Fukagawa NK, Sclater AL, Wong GA. Shannon RP. et al. Effects of recombinant human IGF-1 on glucose and leucine kinetics in men. Am J Physiol 1993:265: E831-8
2300
2301    Giordano M, Castellino P. Carrol CA, DeFronzo RA. Comparison of the effects of human recombinant insulin-like growth factor 1 and insulin on plasma amino acid concentrations and leucine kinetics in humans. Diabetologia 1995:38: 732-8
2302
2303IGF-1/IGF-1 Binding protein 3 complex
2304
2305The major beneficial effect of IGF-1/BP3 in this study appeared to be reduced muscle proteolysis. IGF-1/BP3 significantly reduced net protein degradation rates in muscles from HLS rats. Preservation of muscle weight and protein content paralleled this reduced muscle proteolysis. In a previous study with highly catabolic muscle from dystrophic hamsters, we reported a 27% decrease in muscle protein degradation rates with rhIGF-1 (29); here with IGF-1/BP3, we report a near 40% decrease. A key component of muscle proteolytic pathways, namely calpain-mediated myofibrillar degradation, was also reduced in rhIGF-1-treated dystrophic mice (30)
2306
2307Effects of Insulin-Like Growth Factor-1/Binding protein-3 Complex on Muscle Atrophy in Rats Martin M. Zdanowicz, Experimental Biology and Medicine 228:891-897 (2003) [So there is an action that GH alone nor insulin effects, namely the reduction in protein degradation/breakdown in muscle. Of course GH increases the amount of IGF-1/IGF-1 Binding protein 3 complex.]
2308
2309In humans, IGF-I administration promoted protein anabolism both by stimulating protein synthesis and by inhibiting protein degradation both in muscle and at the whole body level (10, 11).
2310
2311    Elahi D, McAloon-Dyke M, Fukagawa NK, Sclater AL, Wong GA, Shannon RP, Minaker KL, Miles JM, Rubenstein AH, Vandepol CJ, Guler H-P, Good WR, Seaman JJ, and Wolfe RR. Effects of recombinant human IGF-I on glucose and leucine kinetics in men. Am J Physiol Endocrinol Metab 265: E831–E838, 1993.
2312
2313    Fryburg DA. Insulin-like growth factor I exerts growth hormone- and insulin-like actions on human muscle protein metabolism. Am J Physiol Endocrinol Metab 267: E331–E336, 1994.
2314
2315[So IGF-1 administration both stimulates protein synthesis and inhibitsprotein degradation in muscle & the entire body. However the reduction in protein degradation in muscle is unique to this hormone as this is not a benefit of GH's sole actions, of insulin's actions or of androgen action.]
2316
2317Androgens
2318
2319Pharmacological doses of androgens increase lean body mass in normal men (77) and muscle sized in trained athletes (78). The mechanisms responsible for the anabolic effects of testosterone have been explained by Griggs et al. (79). In a group of healthy volunteers, a 12-week administration of a pharmacological dose of testosterone enanthate increased mixed muscle protein synthesis (muscle biopsy during the infusion of labeled leucine) by 27% did not significantly affect leucine estimates of the whole-body protein breakdown...
2320
2321...androgens promote protein anabolism by sparing amino acids from oxidation and increasing their incorporation into proteins, especially muscle proteins.
2322
2323Thus, part of the effects attributed to androgens, namely the suppression of leucine oxidation (51, 52) and the stimulation of whole-body (51-53) and muscle (57- 59) protein synthesis, might be mediated by GH.
2324
2325[So androgens supress amino acid oxidation and increase proteinsynthesis ...either alone or as a synergistic or complementary action of GH.]
2326
2327Thyroid hormones (catabolic NOT anabolic)
2328
2329In contrast, both rates of whole-body protein breakdown and synthesis are increased by the administration of T3 and T4 to normal subjects (110). Under these circumstances net protein catabolism occurs because the stimulation of protein synthesis is overcome by a greater stimulation of amino acid oxidation (110).
2330
2331    Tauveron I, Charrier S, Champredon C, Bonnet Y, Berry C, Bayle G, et al. Response of leucine metabolism to hyperinsulinemia under amino acid replacement in experimental hyperthyroidism. Am J Physiol 1995;269:E499-507 [Thyroid hormones are catabolic because they stimulate breakdown to a greater extent then synthesis.] The data on the role played by normal thyroid hormone concentration in the physiological regulation of everyday protein metabolism in normal humans are very limited. In growing rats it has been suggested that thyroid hormones contribute to the increase in protein synthesis induced by meal absorption (113). This does not appear to be the case in humans, according to the evidence that meal-induced changes inprotein kinetics occur in the absence of significant changes in the plasma concentrations of T3 and T4 (114).
2332
2333    Jepson MM, Bates PC, Millward DJ. The role of insulin and thyroid hormones in the regulation of msucle growth and protein turnover in response to dietary protein. Br J Nutr 1988;59:397-415
2334
2335    Pacy PJ, Price GM, Halliday D, Quevedo MR, Millward DJ. Nitrogen homeostasis in man: the diurnal responses of protein synthesis and degradation and amino acid oxidation to diets with increasing protein intakes. Clin Sci 1994:86:103-18 [Thyroid hormones do not appear to contribute to protein synthesis following meals in humans. In rats yes... In other words these hormones in normal humans do not add to the protein synthesis that meals induce.]
2336
2337Basal concentrations of thyroid hormones have differential effects on individual protein kinetics and they play a role in the physiological regulation of protein metabolism of selectively modulating the synthetic or the catabolic rates of target proteins.
2338
2339[Base levels of thyroid hormones play a general role in modulating both catabolism and synthesis of proteins. Other then restroing abnormalities there doesn't appear to be predictable benefit to manipulating thyroid hormone levels if anabolism is the goal.]
2340
2341Catabolism
2342
2343Cortisol, Glucagon, Thyroid hormones
2344
2345Thus, whole-body and muscle protein catabolism induced by triple hormonal infusions appear to be mediated by a similar mechanism. The hormones, through the stimulation of protein breakdown, increase the intracellular availability of amino acids; the net catabolic effect results from the fact that hormonal action promotes the oxidative disposal of these amino acids more than their utilization for the synthesis of new proteins.
2346
2347[These hormones, especially if they are present together promoteprotein breakdown and rather then making the amino acid pool available for resynthesis, they increase loss by stimulating oxidation.]
2348EOD Calorie Restriction = Longevity?
2349
2350EasyEJL your mind is just wasted when it is mixed in with all the "fluff" posts at AM. You mentioned something that to my mind is an awesome area of research with tremendous potential to make people less susceptible to cancer, better cardiovascular profiles, better memory & less damage to brain, lower oxidative stress, much better insulin sensitivity, prolonged life, ...just on and on...there are a lot of studies going back to the 1940's that demonstrate these positive effect...
2351
2352I became very interested in every other day calorie restriction when I experimented for years with it on myself and found that if I alternated between:
2353
2354a day of very low calories (say between 1000 & 1400) w/ food intake primarily at the beginning and end of the day & cardio exercise(s) in the earlier portion of the day followed by no food intake for several hours...
2355
2356and a day where I ate at about maintenence w/ a higher intake of carbs around a session of weightlifing.
2357
2358I could readily lose fat & retain muscle. In fact I always made minor but consistent strength gains and felt mentally sharp & had energy during the fasted portion of low cal day.
2359
2360I have been researching a pattern of eating involving a day of eating less then 20% of maintenance calories (or a complete fast) followed by eating freely (but not excessively). I have very little doubt that this pattern is as beneficial as calorie restriction diets in promoting longevity. But has the advantage of preserving body mass.
2361
2362It is interesting that on fasted days there is no depletion of glycogen from muscle, circulating levels do go down but stores are drawn from the liver. I conjecture that during periods of no energy intake the body preserves muscle as best it can (at least in the 24 hour period) so that the homo sapien can use his strength to obtain more energy. *
2363
2364What is interesting is that the following non-fasted day when energy intake is occurring the body is more insulin sensitive. In fact over time w/ this pattern of eating the body can become up to 7 times more insulin sensitive.
2365
2366The area that I am attempting to reconcile is whether the use of GHRH/GHRP-6 to restore youthful GH levels (and a little higher IGF-1 levels) undermines the longevity benefits of alternate day calorie restriction?
2367
2368Resveratrol I suspect is not the answer to longevity in humans even though it mimics many of the transcriptional aspects of calorie restriction. It has been shown not to extend lifespan in normal mice. **
2369
2370Eating at 60% of maintenance every day is not desirable, but EOD calorie restriction might be the answer to health and longevity while maintaining the body in a fit muscular state.
2371
2372    - "With the present fasting protocol and maintenance of habitual daily physical activity in the fasting periods, we had expected to detect a decrease in IMTG content in the skeletal muscle. The fact that this was not seen and that muscle glycogen content was unchanged could suggest that skeletal muscle is not immediately involved in recognition of acute energy oscillations." -Effect of intermittent fasting and refeeding on insulin action in healthy men, Nils Halberg, J Appl Physiol 99: 2128-2136, 2005
2373
2374** - Resveratrol delays age-related deterioration and mimics transcriptional aspects of dietary restriction without extending life span, Pearson KJ , Cell Metab. 2008 Aug;8(2):157-68.
2375STUDY: Effect of intermittent fasting and refeeding on insulin action in healthy men
2376
2377Eight healthy young Caucasian men, body mass index 25.7 +- 0.4 kg/m2
2378
2379Throughout the intervention, the subjects were instructed to uphold their normal exercise habits, to maintain their usual macronutrient mixing of their meals, and to eat sufficient quantities of food on the nonfasting days to ensure that their body weight was stable.
2380
2381The fast period was 20 hours. Each fasting period started at 2200 and ended at 1800 the following day (for protocol see Fig. 1). During the fasting periods the subjects were allowed to drink water and were instructed to maintain habitual activities.
2382
2383CONCLUSION:
2384
2385In conclusion, the findings that intermittent fasting increases insulin sensitivity on the whole body level as well as in adipose tissue support the view that cycles of feast and famine are important as an initiator of thrifty genes leading to improvements in metabolic function (6). We suggest that a fastinginduced increase in circulating adiponectin is at least partly responsible for this finding. The change in adiponectin, together with changes in plasma leptin with fasting, underlines the important role of the adipose tissue in recognizing the oscillation in energy stores. Finally, the data indicate that intermittent fasting and physical training may increase insulin action via different mechanisms because muscle energy stores did not change with the present fasting intervention.
2386Caprylic Acid (MCTs) - reduce expression of lipogenic genes
2387
2388Thank you for posting that up BT. MCTs, specifically caprylic acid (octonate) does much more than that. Permit me to introduce you to one of my secrets. Very few people know and understand what follows. Best explained by the study Modulation of adipocyte lipogenesis by octanoate: involvement of reactive oxygen species, Wen Guo, Weisheng Xie and Jianrong Han, Nutrition & Metabolism 2006, 3:30
2389
2390Background:
2391
2392Medium-chain fatty acids (MCFA) belong to a unique type of fatty acids that is metabolized differently from either long-chain fatty acids or carbohydrates. Dietary Medium-chain triglycerides (MCT) inhibit body fat mass growth in both animals and human. Early studies suggest that this effect might be caused by rapid absorption of MCT-derived MCFA and their ß-oxidation in the liver, which reduces the circulating fatty acids available to the adipocytes [11]. This model is supported by the evidence that MCFA enters the ß-oxidation pathway in liver mitochondria independent of carnitine palmitoyl transferase I (CPT-I) [12].
2393
2394[The afore-mentioned was presented by you BT & your wonderful illustrations]
2395
2396However, it does not explain the findings that dietary MCT inhibits lipogenesis in adipocytes [13,14].
2397
2398Furthermore, MCFA are recovered in the adipose tissue fatty acids up to 30 mole % in both animals and humans adapted to MCT diets [6,15-17]. These findings imply that a substantial influx of MCFA into the adipocytes occurs in vivo, which might affect adipose tissue function more than previously appreciated.
2399
2400[MCTs in significant quantity do make there way into fat cells and do what?]
2401
2402Indeed, we found that a reduction in fat mass was associated with reduced expression of lipogenic genes and adipocyte transcription factors in MCT-fed animals [6]. This effect was reproduced in cultured adipocytes treated with octanoate [18]. When added to differentiating rodent preadipocytes, MCFA also inhibits fat accumulation and reduces expression of adipocyte specific proteins [19,20]. In this study, we provide new evidence that octanoate suppresses lipogenesis, at least in part, by inactivating the key adipocyte transcription factor, peroxisome proliferator-activated receptor y (PPARy). Furthermore, our data revealed, for the first time, an involvement of reactive oxygen species (ROS) as a possible intermediate component that might regulate the anti-lipogenic effects.
2403
2404[Wow!]
2405
2406[What is so Wow?]
2407
2408Discussion:
2409
2410Fatty acid oxidation is normally activated only under fasting conditions when circulating levels of insulin and glucose are low. Conversely, lipogenesis is down-regulated by fasting. The mechanistic link between these two events, however, has not been established.
2411
2412In this work, we provided the first evidence that medium-chain octanoate can be ß-oxidized in adipocytes independent of CPT-I regulation. Hence, supplement of octanoate maintains active ß- oxidation in the presence of insulin and glucose. This is correlated with inhibition of lipogenesis and reduction of lipogenic gene expression. In other words, octanoate induces a metabolic state in adipocytes mimicking a fasting condition without actual hormone/nutrient deprivation. Our results also demonstrated that ROS might be involved as a mediator for octanoate in lowering PPARy activity, the master control of lipogenic gene expression.
2413
2414As extensively reviewed previously, PPARy is a prototypical member of the nuclear receptor superfamily which integrates the control of energy, lipid and glucose, homerostasis [50-54]. PPARy binds a variety of small lipophilic compounds derived from metabolism and nutrition. These ligands, in turn, determine cofactor recruitment and regulate the transcription of a variety of metabolic genes. Recent literature highlights the development of partial agonists of PPARy to block adipogenesis and reduce fat mass development [54-59]. In one of our previous studies, we proposed that octanoate might act as a partial agonist for PPARy because it can potentially bind to PPARy as does the long-chain fatty acids [29,60], hence competitively blocking the binding of the latter or other endogenous ligands. This model was supported, but not proved, by the findings that the anti-adipogenic [19] and antilipogenic (this work) effects of octanoate was efficiently blocked by selected synthetic PPARy agonists.
2415
2416The current findings that octanoate induced ROS generation in adipocytes suggest that octanoate might also modulate PPARy activity indirectly via the ROS signaling pathways. It has been well established that ROS activates the stress-responsive protein kinases [61,62], which either directly or indirectly inhibit PPARy activity [47-49,62-67]. In our preliminary studies, we found that octanoate also induced sustained activation of Erk1/2 and JNK/SAPK (data not shown). How these kinase pathways are involved in the regulation of PPARy activity and lipogenesis in our cell system and, more importantly, in primary adipocytes, are currently under investigation.
2417
2418Inhibition of adipocyte lipogenesis can be a useful tool for the prevention of obesity. In this regard, our studies contribute to the scientific basis for the application of MCT in dietary weight management. On the other hand, a complete inhibition of fat mass growth is disastrous since adipocytes play important roles in physiological functions of mammals. Compared to the pharmaceutical inhibitors of lipogenesis [68,69], the effects of octanoate can be considered as moderate and yet might be more desirable for physiological regulation of body fat mass without adversely affecting normal fat tissue functions. According to recent surveys, a majority of the middle age population is moderately over-weighed (BMI 23–27), and a slight increase in BMI in this range is associated with a greater risk for metabolic syndrome [70,71]. It will be of important social and economical values if MCT can be used for body weight regulation in this sub-population, as demonstrated by a recent clinical trial [5].
2419
2420Conclusion:
2421
2422This study demonstrated that octanoate had a direct inhibitory effect on fat storage in adipocytes under conditions that normally favor lipogenesis. This was related to its unique ß-oxidation mechanism which links to elevated cellular ROS levels and subsequent inactivation of PPARy. The exact mechanism by which PPARy is inactivated, in particular, how ROS is involved in this process, still remains to be elucidated. Furthermore, ROS is known to have diverse and complex molecular targets, which might directly or indirectly influence the activities of additional adipocyte transcription factors or modify selected lipogenic proteins [44,71]. Elucidation of these mechanisms will be helpful for the application of MCT for dietary intervention to prevent obesity and may reveal possible pharmaceutical targets to modulate fat metabolism.
2423
2424From the RESULTS an important practical tip [l-carnitine & MCTs (Caprylic Acid) should not be used together & MCTs (Caprylic Acid) are more effective then l-carnitine in the presence of insulin]
2425
2426As shown in Figure 3A, ß-oxidation of octanoate was slightly inhibited (~18%) by insulin, a hormone that promotes the generation of the natural inhibitor of CPT-I [37], and Etomoxir, a pharmaceutical inhibitor of CPT-I. On the other hand, l-carnitine, an activator of CPT-I, caused a ~60% inhibition of octanoate oxidation. A combination of l-carnitine and exogenous oleate further enhanced the inhibition (> 85%). In contrast, ß-oxidation of oleate was increased by l-carnitine more than 2 fold but inhibited by insulin by about 60% (Fig. 3B), consistent with the literature [37]. These results indicate that in adipocytes, octanoate was mainly oxidized independent of CPT-I (> 80%). A small fraction (< 20%), that was sensitive to insulin and etomoxir, might be activated in the cytosol and hence depend on CPT-I to enter the mitochondria. The observation that l-carnitine inhibited, rather than promoted, ß-oxidation of octanoate suggests that activation of CPT-I largely increased the transport of endogenous fatty acids into the ß-oxidation pathway which compete with octanoate for the enzymes downstream from CPT-1. This competition was further enhanced in the presence of added oleate.
2427
2428References:
2429
2430    Bray GA, Lee M, Bray TL: Weight gain of rats fed medium-chain triglycerides is less than rats fed long-chain triglycerides. Int J Obes 1980, 4:27-32.
2431
2432    Hashim SA, Tantibhedyangkul P: Medium chain triglyceride in early life: effects on growth of adipose tissue. Lipids 1987, 22:429-434.
2433
2434    Papamandjaris AA, White MD, Raeini-Sarjaz M, Jones PJ: Endogenous fat oxidation during medium chain versus long chain triglyceride feeding in healthy women. Int J Obes Relat Metab Disord 2000, 24:1158-1166.
2435
2436    Tsuji H, Kasai M, Takeuchi H, Nakamura M, Okazaki M, Kondo K: Dietary medium-chain triacylglycerols suppress accumulation of body fat in a double-blind, controlled trial in healthy men and women. J Nutr 2001, 131:2853-2859.
2437
2438    Nosaka N, Maki H, Suzuki Y, Haruna H, Ohara A, Kasai M, Tsuji H, Aoyama T, Okazaki M, Igarashi O, Kondo K: Effects of margarine containing medium-chain triacylglycerols on body fat reduction in humans. J Atheroscler Thromb 2003, 10:290-298.
2439
2440    Han J, Hamilton JA, Kirkland JL, Corkey BE, Guo W: Medium-chain oil reduces fat mass and down-regulates expression of adipogenic genes in rats. Obes Res 2003, 11:734-744.
2441
2442    St-Onge MP, Ross R, Parsons WD, Jones PJ: Medium-chain triglycerides increase energy expenditure and decrease adiposity in overweight men. Obes Res 2003, 11:395-402.
2443
2444    St-Onge MP, Jones PJ: Greater rise in fat oxidation with medium-chain triglyceride consumption relative to longchain triglyceride is associated with lower initial body weight and greater loss of subcutaneous adipose tissue. Int J Obes Relat Metab Disord 2003, 27:1565-1571.
2445
2446    Bourque C, St-Onge MP, Papamandjaris AA, Cohn JS, Jones PJ: Consumption of an oil composed of medium chain triacyglycerols, phytosterols, and N-3 fatty acids improves cardiovascular risk profile in overweight women. Metabolism 2003, 52:771-777.
2447
2448    St-Onge MP, Bourque C, Jones PJ, Ross R, Parsons WE: Mediumversus long-chain triglycerides for 27 days increases fat oxidation and energy expenditure without resulting in changes in body composition in overweight women. Int J Obes Relat Metab Disord 2003, 27:95-102.
2449
2450    Bach AC, Ingenbleek Y, Frey A: The usefulness of dietary medium-chain triglycerides in body weight control: fact or fancy? J Lipid Res 1996, 37:708-726.
2451
2452    Aas M: Organ and subcellular distribution of fatty acid activating enzymes in the rat. Biochim Biophys Acta 1971, 231:32-47.
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2454    Wiley JH, Leveille GA: Metabolic consequences of dietary medium-chain triglycerides in the rat. J Nutr 1973, 103:829-835.
2455
2456    Lavau MM, Hashim SA: Effect of medium chain triglyceride on lipogenesis and body fat in the rat. J Nutr 1978, 108:613-620.
2457
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2459
2460    Kinkela T, Chanussot F, Bach A, Max JP, Schirardin H, Debry G: Effects of diets containing medium-chain and long-chain triacylglycerols in the genetically obese Zucker fa/fa rat. Composition of fatty acids and triacylglycerols of the liver and adipose tissues. Ann Nutr Metab 1983, 27:404-414.
2461
2462    Sarda P, Lepage G, Roy CC, Chessex P: Storage of medium-chain triglycerides in adipose tissue of orally fed infants. Am J Clin Nutr 1987, 45:399-405.
2463
2464    Guo W, Lei T, Wang T, Corkey BE, Han J: Octanoate inhibits triglyceride synthesis in 3T3-L1 and human adipocytes. J Nutr 2003, 133:2512-2518.
2465
2466    Han J, Farmer SR, Kirkland JL, Corkey BE, Yoon R, Pirtskhalava T, Ido Y, Guo W: Octanoate attenuates adipogenesis in 3T3-L1 preadipocytes. J Nutr 2002, 132:904-910.
2467
2468    Nakajima I, Muroya S, Chikuni K: Growth arrest by octanoate is required for porcine preadipocyte differentiation. Biochem Biophys Res Commun 2003, 309:702-708.
2469
2470    Graves RA, Tontonoz P, Spiegelman BM: Analysis of a tissue-specific enhancer: ARF6 regulates adipogenic gene expression. Mol Cell Biol 1992, 12:1202-1208.
2471
2472    Guo W, Choi JK, Kirkland JL, Corkey BE, Hamilton JA: Esterification of free fatty acids in adipocytes: a comparison between octanoate and oleate. Biochem J 2000, 349:463-471.
2473
2474    Wang T, Zang Y, Ling W, Corkey BE, Guo W: Metabolic partitioning of endogenous fatty acid in adipocytes. Obes Res 2003, 11:880-887.
2475
2476    Guo WLT, Wang T, Corkey BE, Han J: Octanoate inhibits triglyceride synthesis in 3T3-L1 and human adipocytes. J Nutr 2003, 133:2512-2518.
2477
2478    Talior I, Yarkoni M, Bashan N, Eldar-Finkelman H: Increased glucose uptake promotes oxidative stress and PKC-delta activation in adipocytes of obese, insulin-resistant mice. Am J Physiol Endocrinol Metab 2003, 285:E295-302.
2479
2480    Hajri T, Han XX, Bonen A, Abumrad NA: Defective fatty acid uptake modulates insulin responsiveness and metabolic responses to diet in CD36-null mice. J Clin Invest 2002, 109:1381-1389.
2481
2482    Schoonjans K, Peinado-Onsurbe J, Lefebvre AM, Heyman RA, Briggs M, Deeb S, Staels B, Auwerx J: PPARalpha and PPARgamma activators direct a distinct tissue-specific transcriptional response via a PPRE in the lipoprotein lipase gene. EMBO J 15(19):5336-48. 1996 Oct 1
2483
2484    Sato O, Kuriki C, Fukui Y, Motojima K: Dual promoter structure of mouse and human fatty acid translocase/CD36 genes and unique transcriptional activation by peroxisome proliferator- activated receptor alpha and gamma ligands. J Biol Chem 2002, 277(18):15703-11. Epub 2002 Feb 26.
2485
2486    Kliewer SA, Sundseth SS, Jones SA, Brown PJ, Wisely GB, Koble CS, Devchand P, Wahli W, Willson TM, Lenhard JM, Lehmann JM: Fatty acids and eicosanoids regulate gene expression through direct interactions with peroxisome proliferator-activated receptors alpha and gamma. Proc Natl Acad Sci USA 1997, 94:4318-4323.
2487
2488    Shillabeer G, Lau DC: Regulation of new fat cell formation in rats: the role of dietary fats. J Lipid Res 1994, 35:592-600. 31. Shillabeer G, Forden JM, Lau DC: Induction of preadipocyte differentiation by mature fat cells in the rat. J Clin Invest 1989, 84:381-387.
2489
2490    Brandes R, Arad R, Bar-Tana J: Inducers of adipose conversion activate transcription promoted by a peroxisome proliferators response element in 3T3-L1 cells. Biochem Pharmacol 1995, 50:1949-1951.
2491
2492    Ibrahimi A, Teboul L, Gaillard D, Amri EZ, Ailhaud G, Young P, Cawthorne MA, Grimaldi PA: Evidence for a common mechanism of action for fatty acids and thiazolidinedione antidiabetic agents on gene expression in preadipose cells. Mol Pharmacol 1994, 46:1070-1076.
2493
2494    Ailhaud G, Amri EZ, Grimaldi PA: Fatty acids and expression of lipid-related genes in adipose cells. Proc Nutr Soc 1996, 55:151-154.
2495
2496    Ailhaud G, Amri EZ, Grimaldi PA: Fatty acids and adipose cell differentiation. Prostaglandins Leukot Essent Fatty Acids 1995, 52:113-115.
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2498    Amri EZ, Bertrand B, Ailhaud G, Grimaldi P: Regulation of adipose cell differentiation. I. Fatty acids are inducers of the aP2 gene expression. J Lipid Res 1991, 32:1449-1456.
2499
2500    McGarry JD, Sen A, Esser V, Woeltje KF, Weis B, Foster DW: New insights into the mitochondrial carnitinepalmitoyltransferase enzyme system. Biochimie 1991, 73:77-84.
2501
2502    Fujino T, Takei YA, Sone H, Ioka RX, Kamataki A, Magoori K, Takahashi S, Sakai J, Yamamoto TT: Molecular identification and characterization of two medium-chain acyl-CoA synthetases, MACS1 and the Sa gene product. J Biol Chem 2001, 276:35961-35966.
2503
2504    Vessey DA, Lau E, Kelley M, Warren RS: Isolation, sequencing, and expression of a cDNA for the HXM-A form of xenobiotic/ medium-chain fatty acid:CoA ligase from human liver mitochondria. J Biochem Mol Toxicol 2003, 17:1-6.
2505
2506    Oka Y, Kobayakawa K, Nishizumi H, Miyamichi K, Hirose S, Tsuboi A, Sakano H: O-MACS, a novel member of the medium-chain acyl-CoA synthetase family, specifically expressed in the olfactory epithelium in a zone-specific manner. Eur J Biochem 2003, 270:1995-2004.
2507
2508    Lei T, Xie W, Watkins PA, Guo W: Activation of medium-chain fatty acids in 3T3-L1 adipocytes and mouse adipose tissue. Obes Res 2003, 11:180P. (abstract)
2509
2510    Hickson-Bick DL, Sparagna GC, Buja LM, McMillin JB: Palmitateinduced apoptosis in neonatal cardiomyocytes is not dependent on the generation of ROS. Am J Physiol Heart Circ Physiol 2002, 282:H656-664.
2511
2512    Yamagishi SI, Edelstein D, Du XL, Kaneda Y, Guzman M, Brownlee M: Leptin induces mitochondrial superoxide production and monocyte chemoattractant protein-1 expression in aortic endothelial cells by increasing fatty acid oxidation via proteinkinase A. J Biol Chem 2001, 276:25096-25100.
2513
2514    Yamagishi S, Okamoto T, Amano S, Inagaki Y, Koga K, Koga M, Choei H, Sasaki N, Kikuchi S, Takeuchi M, Makita Z: Palmitate-induced apoptosis of microvascular endothelial cells and pericytes. Mol Med 2002, 8:179-184.
2515
2516    Turrens JF, Alexandre A, Lehninger AL: Ubisemiquinone is the electron donor for superoxide formation by complex III of heart mitochondria. Arch Biochem Biophys 1985, 237:408-414.
2517
2518    Young TA, Cunningham CC, Bailey SM: Reactive oxygen species production by the mitochondrial respiratory chain in isolated rat hepatocytes and liver mitochondria: studies using myxothiazol. Arch Biochem Biophys 2002, 140:65-72.
2519
2520    Hu E, Kim JB, Sarraf P, Spiegelman BM: Inhibition of adipogenesis through MAP kinase-mediated phosphorylation of PPARgamma. Science 1996, 274:2100-2103.
2521
2522    Yang W, Hong YH, Shen XQ, Frankowski C, Camp HS, Leff T: Regulation of transcription by amp-activated protein kinase: phosphorylation of p300 blocks its interaction with nuclear receptors. J Biol Chem 2001, 276:38341-38344.
2523
2524    Camp HS, Tafuri SR, Leff T: c-Jun N-terminal kinase phosphorylates peroxisome proliferator-activated receptor-gamma1 and negatively regulates its transcriptional activity. Endocrinology 1999, 140:392-397.
2525
2526    Debril MB, Renaud JP, Fajas L, Auwerx J: The pleiotropic functions of peroxisome proliferator-activated receptor gamma. J Mol Med 2001, 79:30-47.
2527
2528    Rosen ED, Spiegelman BM: PPARgamma: a nuclear regulator of metabolism, differentiation, and cell growth. J Biol Chem 2001, 276:37731-37734.
2529
2530    Hihi AK, Michalik L, Wahli W: PPARs: transcriptional effectors of fatty acids and their derivatives. Cell Mol Life Sci 2002, 59:790-798.
2531
2532    Sewter C, Vidal-Puig A: PPARgamma and the thiazolidinediones: molecular basis for a treatment of 'Syndrome X'? Diabetes Obes Metab 2002, 4:239-248.
2533
2534    Knouff C, Auwerx J: Peroxisome proliferator-activated receptor- gamma calls for activation in moderation: lessons from genetics and pharmacology. Endocr Rev 2004, 25:899-918.
2535
2536    Oberfield JL, Collins JL, Holmes CP, Goreham DM, Cooper JP, Cobb JE, Lenhard JM, Hull-Ryde EA, Mohr CP, Blanchard SG, Parks DJ, Moore LB, Lehmann JM, Plunket K, Miller AB, Milburn MV, Kliewer SA, Willson TM: A peroxisome proliferator-activated receptor gamma ligand inhibits adipocyte differentiation. Proc Natl Acad Sci U S A 1999, 96:6102-6106.
2537
2538    Mukherjee R, Hoener PA, Jow L, Bilakovics J, Klausing K, Mais DE, Faulkner A, Croston GE, Paterniti JR Jr: A selective peroxisome proliferator-activated receptor-gamma (PPARgamma) modulator blocks adipocyte differentiation but stimulates glucose uptake in 3T3-L1 adipocytes. Mol Endocrinol 2000, 14:1425-1433.
2539
2540    Camp HS, Chaudhry A, Leff T: A novel potent antagonist of peroxisome proliferator-activated receptor gamma blocks adipocyte differentiation but does not revert the phenotype of terminally differentiated adipocytes. Endocrinology 2001, 142:3207-3213.
2541
2542    Lee G, Elwood F, McNally J, Weiszmann J, Lindstrom M, Amaral K, Nakamura M, Miao S, Cao P, Learned RM, Chen JL, Li Y: T007 a selective ligand for peroxisome proliferator-activated receptor gamma, functions as an antagonist of biochemical and cellular activities. J Biol Chem 0907, 277:19649-19657.
2543
2544    Leesnitzer LM, Parks DJ, Bledsoe RK, Cobb JE, Collins JL, Consler TG, Davis RG, Hull-Ryde EA, Lenhard JM, Patel L, Plunket KD, Shenk JL, Stimmel JB, Therapontos C, Willson TM, Blanchard SG: Functional consequences of cysteine modification in the ligand binding sites of peroxisome proliferator activated receptors by GW9662. Biochemistry 2002, 28:6640-6650.
2545
2546    Xu HE, Lambert MH, Montana VG, Parks DJ, Blanchard SG, Brown PJ, Sternbach DD, Lehmann JM, Wisely GB, Willson TM, Kliewer SA, Milburn MV: Molecular recognition of fatty acids by peroxisome proliferator-activated receptors. Mol Cell 1999, 3:397-403.
2547
2548    Choi SL, Kim SJ, Lee KT, Kim J, Mu J, Birnbaum MJ, Soo Kim S, Ha J: The regulation of amp-activated protein kinase by H(2)O(2). Biochem Biophys Res Commun 2001, 287:92-97.
2549
2550    Souza SC, Palmer HJ, Kang YH, Yamamoto MT, Muliro KV, Paulson KE, Greenberg AS: TNF-alpha induction of lipolysis is mediated through activation of the extracellular signal related kinase pathway in 3T3-L1 adipocytes. J Cell Biochem 2003, 89:1077-1086.
2551
2552    Floyd ZE, Stephens JM: Interferon-gamma-mediated activation and ubiquitin-proteasome-dependent degradation of PPARgamma in adipocytes. J Biol Chem 2002, 277:4062-4068.
2553
2554    Huang WC, Chio CC, Chi KH, Wu HM, Lin WW: Superoxide anion-dependent Raf/MEK/ERK activation by peroxisome proliferator activated receptor gamma agonists 15-deoxydelta( 12,14)-prostaglandin J(2), ciglitazone, and GW1929. Exp Cell Res 2002, 277:192-200.
2555
2556    Hedvat M, Jain A, Carson DA, Leoni LM, Huang G, Holden S, Lu D, Corr M, Fox W, Agus DB: Inhibition of HER-kinase activation prevents ERK-mediated degradation of PPARgamma. Cancer Cell 2004, 5:565-574.
2557
2558    Tanabe Y, Nakayama K: Mechanical stretching inhibits adipocyte differentiation of 3T3-L1 cells: the molecular mechanism and pharmacological regulation. Nippon Yakurigaku Zasshi 2004, 124:337-344.
2559
2560    Tanabe Y, Koga M, Saito M, Matsunaga Y, Nakayama K: Inhibition of adipocyte differentiation by mechanical stretching through ERK-mediated downregulation of PPARgamma2. J Cell Sci 2004, 117:3605-3614.
2561
2562    Goransson O, Ryden M, Nilsson R, Arner P, Degerman E: Dimethylaminopurine inhibits metabolic effects of insulin in primary adipocytes. In J Nutr Biochem 2004:303-312.
2563
2564    Thupari JN, Landree LE, Ronnett GV, Kuhajda FP: C75 increases peripheral energy utilization and fatty acid oxidation in dietinduced obesity. Proc Natl Acad Sci U S A 2002, 99:9498-9502.
2565
2566    St-Onge MP: Relationship between body composition changes and changes in physical function and metabolic risk factors in aging. Curr Opin Clin Nutr Metab Care 2005, 8:523-528.
2567
2568    St-Onge MP, Janssen I, Heymsfield SB: Metabolic syndrome in normal-weight Americans: new definition of the metabolically obese, normal-weight individual. Diabetes Care 2004, 27:2222-2228.
2569
2570Fish Oil (DHA) increases metabolism (fat loss)
2571
2572I thought you might be interested in this because almost no nutritionists or people involved in bodybuilding know this.
2573
2574But in the world of aging and longevity research there is the knowledge that the lipid make up of the cellular membrane influences cellular metabolism. High DHA content in phospholipids of the cellular membrane is associated with high metabolic activity and this leads into the "membrane pacemaker" theory of metabolism.
2575
2576This theory proposes that highly polyunsaturated acyl chains impart physical properties to cellular membrane bilayers that enhance and speed up the molecular activity of membrane proteins and consequently the metabolic activity of cells, tissues and the whole animal.
2577
2578There is a positive correlation in the animal kingdom between body size and cellular metabolism with smaller animals possessing cellular membranes with higher DHA content and thus higher cellular metabolisms. Larger animals, humans for instance have cellular membranes with a lot less DHA and thus slower cellular metabolism.
2579
2580All of this is correlated to lifespan. Highly polyunsaturated acyl chains (primarily DHA) are very susceptible to peroxidative damage. This kind of damage shortens lifespan.
2581
2582The brain however is not correlated to any of this and in humans posses high DHA content in the cellular membrane & thus higher metabolism. It is thought that evolution probably weeded out those sluggish thought creatures that had slower brain cell metabolism.
2583
2584How does it work? Well the physical properties of polyunsaturates primarily DHA are such that these lipid chains are flexible and active compared to unsaturated lipids. Because of the active or rapid movement of DHA lipids they exert lateral pressure on neighboring molecules in the cellular membrane. This creates greater activity in membrane enzymes, Na+/K+-ATPase molecules and thus ion channels become approximtely 25% more active. A large part of cellular energy goes into operating those channels.
2585
2586Similar sorts of activity occur in the mitochondrial membrane proteins.
2587
2588A good & recent review of all of this is The links between membrane composition, metabolic rate and lifespan, A.J. Hulbert, Comparative Biochemistry and Physiology, Part A 150 (2008) 196–203
2589
2590Now we know from source material such as Evolutionary Aspects of Diet, the Omega-6/Omega-3 Ratio, and Gene Expression by Artemis P. Simopoulos found in the book Phytochemicals: Nutrient-Gene Interactions, Mark S. Meskin (Editor), CRC; 1 edition (February 22, Phytochemicals: Nutrient-Gene Interactions, Mark S. Meskin (Editor), CRC; 1 edition (February 22, 2006) that:
2591
2592"... the polyunsaturated fatty acid (PUFA) composition of cell membranes is to a great extent dependent on the dietary intake."
2593
2594So if you ingest a large quantity of Omega 3 fatty acids which contain high DHA content you will alter the makeup of the cellular membrane such that it is composed of more DHA which will increase cellular metabolism.
2595
2596This is great for dieting but increases the potential oxidative damage. Enough to effective lifespan? Probably not. But it should increase energy expenditure and thus be beneficial on a diet.
2597CREATING A BACKBONE AROUND WHICH TO LOSE FAT
2598
2599Glucose is an indispensable metabolic fuel for the brain. For the reason that the brain is unable to synthesize glucose or store more than a few minutes supply as glycogen, it is critically dependent on a continuous supply of glucose from the circulation. "At normal (or elevated) arterial glucose concentrations, the rate of blood-to-brain glucose transport exceeds the rate of brain glucose metabolism. However, as arterial glucose levels fall below the physiological range, blood-to-brain glucose transport becomes limiting to brain glucose metabolism, and ultimately survival." - Hypoglycemia in Diabetes, Philip E. Cryer,Diabetes Care 26:1902-1912, 2003
2600
2601So what happens at various blood glucose levels?
2602
2603For practical purposes we can say that the body desires to maintain a stable glucose level in blood plasma of around 90 ng/dL. Blood glucose levels above that threshold are viewed as excess energy and this engenders a storage response via the pancreatic secretion of insulin. The hormone insulin removes glucose from blood plasma until levels return to 90ng/dL at which point insulin ceases to be active.
2604
2605Below that insulin triggering blood glucose threshold of 90ng/dL, down to about 70ng/dL, there is insufficient circulating energy and therefore the hormone glucagon is released to catabolize stored energy and make it available to the brain and body. Physical activity or energy demanding activity without the presence of circulating glucose or concurrent intake of food requires stored energy. Activity is the catalyst that drives the blood glucose level below 90ng/dL.
2606
2607Below 70ng/dL of glucose in blood plasma the body becomes concerned and because the brain is a critical organ and needs glucose, this threshold is considered critical. The hormone epinephrine (adrenaline) is released at this stage in order to trigger a quick release of stored energy to get blood glucose levels back to normal.
2608
2609The body when it is in this emergency state will burn anything for fuel and muscle can be catabolized. It is best to avoid this state.
2610
2611When you diet you can not lose fat in the presence of the hormone insulin. You want to have the hormone glucagon active and this requires that your blood glucose levels be between 70ng/dL and 90ng/dL. Glucagon acts to free up stored energy by signaling the adipocytes to activate Hormone-sensitive lipase which converts triglycerides into free fatty acids.
2612
2613Hormone-sensitive lipase is a vital component of fat mobilization and is a positively active force in the presence of glucagon and inhibited in the presence of insulin.
2614
2615Fatty acids have very low solubility in the blood however serum albumin, binds free fatty acids, and thereby increases their effective solubility by a factor of about 1000. Serum albumin transports fatty acids to organs such as muscle and liver for oxidation and this happens when blood sugar is low.
2616
2617So what is the minimal amount of glucose needed to trigger insulin & why again is insulin bad?
2618
2619From the textbook Biochemical and Physiological Aspects of Human Nutrition, Stipanuk et al. ed. 2000
2620
2621Insulin ...is secreted in response to changes in circulating glucose; a change of as little as2mg/100ml of plasma can be detected by the pancreas. Insulin release can also be stimulated in response to certain amino acids in the circulation. Other important signals for insulin secretion include gut hormones and nervous stimulation. - p395
2622
2623In adipose tissue insulin increases fatty acid uptake and triacylglycerol storage via increases in lipoprotein lipase activity, and at the same time decreases lipolysis by decreasing hormone-sensitive lipase activity. The latter may be one of insulin's strongest actions because it occurs at very low insulin levels and effectively lowers the levels of free fatty acids in the circulation thereby decreasing there utilization as fuel. - p396
2624
2625Is there way to minimize glucose's influence?
2626
2627Again from the textbook Biochemical and Physiological Aspects of Human Nutrition, Stipanuk et al. ed. 2000
2628
2629Soluable viscous polysaccharides [certain fibers] can delay and even interfere with the absorption of nutrients...
2630
2631Positive benefits of delayed nutrient absorption include an improvement of glucose tolerance and a lowering of serum cholesterol levels. Delayed absorption of carbohydrates results in a lower postprandial (following a meal) glucose level. In general the more viscous the fiber the greater the effect on blood glucose. This is similar to the effect seen with eating several small meals rather than one large meal. When glucose is absorbed in small amounts over an extended period, such as seen with viscous fibers, the insulin response is attenuated (Pick, et al. (1996) Oat bran concentrate bread products improve long term control of diabetes: A pilot study J. Am Diet Assoc 96:1254-1261) ...
2632
2633Viscosity of the polysaccharides and their ability to form gels in the stomach appear to slow gastric emptying. This in turn results in a more uniform presentation of the meal to the small intestine for absorption. [Poorly soluble fibers that do not form gels such as wheat and cellulose have little effect...unlike those that do which include guar gum, pectin, psyllium, oat bran.] - p146. 147
2634
2635A Practical Experiment
2636
2637For two days I used my glucose monitor to check my blood glucose after ingestion of coffee. • Black coffee w/ no additives = zero rise in glucose • Black coffee w/ Stevia = a 2 point rise in glucose • Black coffee w/ Splenda = a 5 - 8 point rise in glucose. • Coffee w/ Splenda & generic Coffee Mate creamer = 15+ point rise in glucose • Coffee w/ Splenda & 2% Lactose free Milk = 17+ point rise in glucose
2638
2639So for me the caffeine in a cup of coffee does not effect blood glucose BUT the additives sure as heck do!
2640
2641How do you reduce the rise in blood glucose w/ these additives (besides the obvious)? ....add FIBER.
2642
2643So ingesting 2 grams of Psyllium Husk powder just prior to drinking Coffee w/ Splenda & Coffee Mate creamer resulted in only a 4 point rise in blood glucose. WOW!
2644
2645So how does Growth Hormone fit in to all of this?
2646
2647First recognize that there will be periods of time post meal where blood glucose and thus insulin will be elevated. There is no fat loss during this time and Growth Hormone will not be effective during these periods.
2648
2649With this recognition it makes sense to reduce the amplitude and area under the curve (in graph-type language) of insulin spikes. Meals should be constructed with both the glycemic index of foods in mind and the total glycemic load of the meal. Fiber should be used to reduce blood glucose levels.
2650
2651With this recognition it makes sense to maximize the time period when glucagon is active. That requires insulin to return to baseline quickly after a meal and a sufficient period of time between meals to allow glucagon to have an effective impact. Activity between meals as well as the presence of GH will have positive impacts on fat loss.
2652
2653The reason it is necessary to write about everything in this post is so that you understand how easy it is to waste Growth Hormones fat loss potential and what one must do to maximize GH's fat loss power.
2654
2655Too often someone will use GH and admit that their diet wasn't very good. That negates much of GH's positive impact on fat loss.
2656
2657I also wanted to put GH into a proper context which sadly is often lacking in people who hope for better body attainment. The things I have barely touched on are of utmost importance and make up the backbone of a sound fat loss protocol.
2658
2659GH can be a very useful adjunct to a properly constructed protocol which focuses on food intake with proper hormonal impact and sustained activity level.
2660
2661Use of GH
2662
2663From other posts we understand that GH has a dual role to play in a diet. It can increase the rate of fat loss and it can help inhibit the breakdown of muscle. So you want to administer GH in smaller amounts, you want to have off periods (i.e. time when GH is not active) so that the intracellular pathways can reset and you want to maximize the frequency of administration.
2664
2665So we need to understand the impact of GH dose on levels of GH in plasma to set a schedule. We can extrapolate from the chart from the GH study posted above. Assuming a linear relationship (since 7.5ius were active for 12 hours & 15ius for 24 hours) we can assume that a dose of 2ius of synthetic GH administration will elevate GH in plasma for 3.2 hours.
2666
2667If we need about 4 hours off (we can probably round down to 3.8 hours) we can dose 2ius of GH every 7 hours. For ease of fitting a dosing schedule into our lives we can round up to 8 hours and say that we can dose 2ius three times a day spaced out by 7-8 hours.
2668
2669Since GH isn't effective for fat loss in the presence of insulin we probably want the meals that have the biggest impact on blood glucose and thus insulin to be ingested during the time GH is not active. After that meal is digested and insulin rises and then falls back to 90ng/dL we can administer GH and be confident it will have a positive impact on our overall fat loss protocol.
2670Further Note on GH & Insulin
2671
2672In plain language, GH in certain circumstances increases glucose uptake identical to that of insulin into both muscle and adipose tissue. This involves translocations of glut 4 and to a lesser extent glut 1 from an intracellular pool to the plasma membrane. BUT in order for this to happen there must be an absence of GH for prolonged periods of time. It appears that this rarely occurs because the base level of GH is still too high to create this effect. *
2673
2674Of more importance is the "likely" effect of GH on glucose transport into adipose tissue. GH, dose dependently reduces glucose transport (diabetogenic effect). The addition of GH to adipocytes in vitro and dose dependently in vivo reduces the rate of glucose uptake in a way that we could characterize as the opposite of the insulin effect.
2675
2676"The data reported here not only confirm the earlier findings but also further demonstrate the importance of GH in vivo for the restriction of basal glucose transport in adipocytes. ... The data give evidence for the importance of GH in vivo, in balance with insulin, for the control of the activity of the glucose carrier in adipose tissue." - Glucose transport in adipocytes and its control by growth hormone in vivo, Schoenle et al. 242 (6): E368. (1982)
2677
2678So there is a good possibility that although GH in the presence of insulin will not lead to substantial fat lossvia lipolysis, it will inhibit the uptake of glucose into adipose tissue. This leads us to the generalization that concurrent administration of GH & insulin will skew nutrient partitioning in favor of muscle tissue and away from adipose tissue.
2679
2680One further note of interest though is this glucose uptake inhibiting effect of GH leads to a restoration of sensitivity to insulin in that tissue.
2681
2682    - Cellular mechanism of the insulin-like effect' of growth hormone in adipocytes Rapid translocation of the HepG2-type and adipocyte/muscle glucose transporters, Tanner, J. W. et al, Biochem. J. (1992) 282, 99-106
2683
2684Age-Related Changes in Slow Wave Sleep and Relationship With Growth Hormone Levels
2685
2686I've tried to emphasize that Slow Wave Sleep (SW) and Growth Hormone (GH) are not merely positively correlated but are intricately bound together such that a change in one leads to a change in the other. That is why from the start I have attempted to underscore that a pre-bed dose of Growth Hormone Releasing Hormone (GHRH) & Growth Hormone Releasing Peptide 6 (GHRP-6) will increase that vital period of sleep known as Slow Wave Sleep which has restorative benefits beyond amplified GH release.
2687
2688The following study is fascinating for all of us because it reveals that somatopause begins dramatically between age 25 and 35. The following study published in the prestigious Journal of the AmericanMedical Association is well worth examining.
2689
2690The chronology of aging of GH secretion follows a pattern remarkably similar to that of SW sleep. Thus, in men, the so-called "somatopause" occurs early in adulthood, between age 25 and 35 years, an age range that corresponds to the human life expectancy before the development of modern civilization and is essentially completed by the end of the fourth decade.
2691
2692Our analyses further indicate that reduced amounts of SW sleep, independent of age, are partly responsible for reduced GH secretion in midlife and late life. That this correlative evidence reflects a common mechanism underlying SW sleep generation and GH release rather than an indirect association is supported by 2 studies that have shown that pharmacological enhancement of SW sleep results in increased GH release. - Age-Related Changes in Slow Wave Sleep and REM Sleep and Relationship With Growth Hormone and Cortisol Levels in Healthy Men, Eve Van Cauter, PhD; Rachel Leproult, MS; Laurence Plat, MD,JAMA. 2000;284:861-868
2693
2694The objective of the study was, to determine the chronology of age-related changes in sleep duration and quality (sleep stages) in healthy men and whether concomitant alterations occur in GH and cortisol levels.
2695
2696They combined data from a series of studies conducted between 1985 and 1999 at 4 laboratories which examined 149 healthy men, aged 16 to 83 years, with a mean (SD) body mass index of 24.1 (2.3) kg/m2, without sleep complaints or histories of endocrine, psychiatric, or sleep disorders.
2697
2698They created twenty-four–hour profiles of plasma GH and cortisol levels and polygraphic sleep recordings and found the following results:
2699
2700The mean (SEM) percentage of deep slow wave sleep decreased from 18.9% (1.3%) during early adulthood (age 16-25 years) to 3.4% (1.0%) during midlife (age 36-50 years) and was replaced by lighter sleep (stages 1 and 2) without significant increases in sleep fragmentation or decreases in rapid eye movement (REM) sleep.
2701
2702The transition from midlife to late life (age 71-83 years) involved no further significant decrease in slow wave sleep but an increase in time awake of 28 minutes per decade at the expense of decreases in both light non-REM sleep (-24 minutes per decade; P<.001) and REM sleep (-10 minutes per decade; P<.001).
2703
2704The decline in slow wave sleep from early adulthood to midlife was paralleled by a major decline in GH secretion (-372 µg per decade; P<.001). From midlife to late life, GH secretion further declined at a slower rate (-43 µg per decade; P<.02).
2705
2706Independently of age, the amount of GH secretion was significantly associated with slow wave sleep (P<.001).
2707
2708Increasing age was associated with an elevation of evening cortisol levels (+19.3 nmol/L per decade; P<.001) that became significant only after age 50 years, when sleep became more fragmented and REM sleep declined. A trend for an association between lower amounts of REM sleep and higher evening cortisol concentrations independent of age was detected (P<.10).
2709
2710For a deeper read I include the following Introduction & Comments which elaborate on the significance of the results. I strongly encourage any one interested in anti-aging to read it so that they can adopt the appropriate compensatory strategies.
2711
2712INTRODUCTION
2713
2714Decreased subjective sleep quality is one of the most common health complaints of older adults.1 The most consistent alterations associated with normal aging include increased number and duration of awakenings and decreased amounts of deep slow wave (SW) sleep (ie, stages 3 and 4 of non–rapid eye movement (non-REM) sleep).2-4 REM sleep appears to be relatively better preserved during aging.3-7 The age at which changes in amount and distribution of sleep stages appear is unclear because the majority of studies have been based on comparisons of young vs older adults. Several investigators have noticed that there are marked decreases in SW sleep in early adulthood in men but not in women.8-11
2715
2716Sleep is a major modulator of endocrine function, particularly of pituitary-dependent hormonal release. Growth hormone (GH) secretion is stimulated during sleep and, in men, 60% to 70% of daily GH secretion occurs during early sleep, in association with SW sleep.12 Whether decrements in SW sleep contribute to the well-known decrease in GH secretion in normal aging is not known.13-15
2717
2718In contrast to the enhanced activity of the GH axis during sleep, the hypothalamic-pituitary-adrenal (HPA) axis is acutely inhibited during early SW sleep.16-20 Furthermore, even partial sleep deprivation results in an elevation of cortisol levels the following evening.21 Thus, both decreased SW sleep and sleep loss resulting from increased sleep fragmentation could contribute to elevating cortisol levels. An elevation of evening cortisol levels is a hallmark of aging14-15,22 that is thought to reflect an impairment of the negative feedback control of the HPA axis and could underlie a constellation of metabolic and cognitive alterations.23-25
2719
2720The present study defines the chronology of age-related changes in sleep duration and quality (ie, amounts of sleep stages), GH secretion, and cortisol levels in healthy men and examines whether decrements in sleep quality are associated with alterations of GH and cortisol levels.
2721
2722...
2723
2724COMMENT
2725
2726The present analysis demonstrates that, in healthy men, aging affects SW sleep and GH release with a similar chronology characterized by major decrements from early adulthood to midlife. In contrast, the impact of age on REM sleep, sleep fragmentation, and HPA function does not become apparent until later in life. The analysis further suggests that age-related alterations in the somatotropic and corticotropic axes may partially reflect decreased sleep quality.
2727
2728Human sleep is under the dual control of circadian rhythmicity and of a homeostatic processrelating the depth of sleep to the duration of prior wakefulness.44 This homeostatic process involves a putative neural sleep factor that increases during waking and decays exponentially during sleep. Slow wave sleep is primarily controlled by the homeostatic process. Circadian rhythmicity is an oscillation with a near 24-hour period generated by a pacemaker located in the hypothalamic suprachiasmatic nucleus. Circadian rhythmicity plays an important role in sleep timing, sleep consolidation, and the distribution of REM sleep.45 The present data indicate that an alteration in sleep-wake homeostasis is an early biological marker of aging in adult men. In contrast, components of sleep that are under the control of the circadian pacemaker appear to be relatively well preserved until late in life.
2729
2730The chronology of aging of GH secretion follows a pattern remarkably similar to that of SW sleep. Thus, in men, the so-called "somatopause" occurs early in adulthood, between age 25 and 35 years, an age range that corresponds to the human life expectancy before the development of modern civilization and is essentially completed by the end of the fourth decade. Our analyses further indicate that reduced amounts of SW sleep, independent of age, are partly responsible for reduced GH secretion in midlife and late life. That this correlative evidence reflects a common mechanism underlying SW sleep generation and GH release rather than an indirect association is supported by 2 studies that have shown that pharmacological enhancement of SW sleep results in increased GH release.46-47 Also supporting a causal relationship between decreased sleep quality and reduced nocturnal GH secretion are studies inpatients with sleep apnea showing a marked increase in GH release following treatment with positive airway pressure.48-49 The reverse interaction between sleep and GH, ie, a deleterious impact of reduced somatotropic function on sleep, is also possible since studies in both normal and pathological conditions have shown that GH-releasing factor and GH influence sleep quality.12, 50 In the present study of nonobese men, the finding of a negative impact of BMI on both GH secretion during waking and amount of SW sleep is consistent with the hypothesis that inhibition of the GH axis may adversely affect sleep regulation.
2731
2732While the clinical implications of decreased SW sleep are still unclear, the relative GH deficiency of the elderly is associated with increased fat tissue and abdominal obesity, reduced muscle mass and strength, and reduced exercise capacity.51-53 Multiple trials are currently examining the clinical usefulness and safety of replacement therapy with recombinant GH, the other hormones of the GH axis, and synthetic GH secretagogues in elderly adults without pathological GH deficiency. While the benefits of such interventions are still unproven, the present findings suggest that they should target a younger age range than currently envisioned, ie, individuals in early midlife rather than those older than 65 years,when peripheral tissues have been continuously exposed to very low levels of GH for at least 2 decades. Furthermore, since pharmacological enhancement of SW sleep in young adults has been shown to result in a simultaneous and proportional increase in GH release 46-47 and ongoing studies in our laboratory indicate that similar effects can be obtained in older subjects,drugs that reliably stimulate SW sleep may represent a novel class of GH secretagogues.
2733
2734The present data demonstrate that the amount of REM sleep is reduced by approximately 50% in late life vs young adulthood. However, reduced amounts of REM sleep and significant sleep fragmentation do not occur until after age 50 years. The impact of aging on cortisol levels followed the same chronology. Aging was associated with an elevation of evening cortisol levels, reflecting an impaired ability to achieve evening quiescence following morning stimulation. Studies in both animals and humans have indicated that deleterious effects of HPA hyperactivity are more pronounced at the time of the trough of the rhythm than at the time of the peak.25, 54 Thus, modest elevations in evening cortisol levels could facilitate the development of central and peripheral disturbances associated with glucocorticoid excess, such as memory deficits and insulin resistance,24-25 and further promote sleep fragmentation. Indeed, elevated cortisol levels may promote awakenings.55-56
2735
2736Elevated evening cortisol levels in late life probably reflect an impairment of the negative feedback control of the HPA axis in aging. Our analyses suggest that there is a relationship between this alteration of HPA function and decreased amounts of REM sleep that is independent of age. The data generally support the concept that decreased sleep quality contributes to the allostatic load, ie, the wear and tear resulting from overactivity of stress-responsive systems.57
2737
2738The present study focused on the effects of aging on the relationship between sleep and the somatotopic and corticotropic axes in men because the predominant GH secretion occurs during sleep in men but not in women11 and because there is evidence to suggest that the marked decreases in SW sleep in early adulthood occur in men but not in women.8-11 Whether conclusions similar to those obtained for men hold for women will require a separate evaluation as sex differences in sleep quality as well as 24-hour profiles of GH and cortisol secretion have been well documented in both young and older adults.11-12,22
2739
2740In conclusion, in healthy men, the distinct changes in sleep quality that characterize the transitions from early adulthood to midlife, on the one hand, and from midlife to old age, on the other hand, are each associated with specific alterations in hormonal systems that are essential for metabolic regulation. Strategies to prevent or limit decrements of sleep quality in midlife and late life may therefore represent an indirect form of hormonal therapy with possible beneficial health consequences.
2741
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2857
2858Growth Hormone Receptor structure, post-biogenesis behavior and degradation
2859
2860The following was originally created primarily for my benefit and serves as a basic summary of Growth Hormone Receptor structure, post-biogenesis behavior and degradation.
2861
2862It is not intended for a wider audience and is not a Datbtrue copyrighted article. It represents the current state of knowledge in the aforementioned area (October, 2008) and was derived primarily from an unpublished paper by Stuart J. Frank & Serge Y. Fuchs on growth hormone receptor abundance and function and from Growth hormone receptor; mechanism of action, Andrew J. Brooks, Jong Wei Wooh, Kathryn A. Tunny, Michael J. Waters, The International Journal of Biochemistry & Cell Biology 40 (2008) 1984–1989
2863
2864These unrefined notes are for educational use only.
2865
2866GHR Structure
2867
2868The growth hormone receptor (GHR) is a member of the cytokine receptor superfamily. Cytokines is a general category encompassing signaling proteins and glycoproteins (often cellular membrane proteins) that similar to hormones and neurotransmitters facilitate cellular communication. [12,13] It is a type I cytokine receptor as is the prolactin receptor, which in essence means it is connected to Janus kinase (JAK) which acts as its primary mediator of signaling events.
2869
2870Physically the GHR is composed of 620 residues (a residue is an individual amino acid in a peptide chain). 350 of these residues reside inside the cell and make up what is known as the intracellular domain. 246 of these residues reside outside the cell and make up what is known as the extracellular domain. The remaining 24 residues reside in the membrane of the cell and make up what is known as the transcellular domain. [13-16]
2871
2872The GHR extracellular domain consists of two fibronectin type III beta sandwich domains connected by a short flexible linker.
2873
2874The intracellular domain comprises Box 1 and Box 2 motifs which bind the tyrosine kinase, Janus kinase 2 (JAK2) and several tyrosine residues that act as substrates for phoshorylation by JAK2 and thus become binding sites for SH2 domain proteins.
2875
2876A Kinase is a type of enzyme that transfers phosphate groups from high-energy donor molecules, such as ATP, to specific target molecules (substrates) in a process called "phosphorylation".
2877
2878Since cytokine receptors such as GHR possess no catalytic kinase activity, they rely on the Janus kinase family of tyrosine kinases to phosphorylate and activate downstream proteins involved in their signal transduction pathways.
2879
2880Phosphorylation of a substrate by tyrosine kinases acts as a switch to trigger binding to an SH2 domain-containing protein. STAT & PI3K proteins possess an SH2 "docking" protein and once bound begin to exert their respective effects.
2881
2882The growth hormone (GH) molecule intiates this phosphorylation process by binding to one of the two GHR domains via its site of stongest attraction. For the 22kDa form of GH it would be site 1. Once bound via GH site 1 to one of the two GHR domains the GH molecule binds to the second GHR domain via the GH molecule location known as site 2.
2883
2884Note that the result of the GH molecule binding with the two receptor domains does not have the effect of connecting the two receptor domains for they were already connected by a short flexible linker. Rather the binding of the GH molecule to the GHR causes a repositioning of the intracellular domains, resulting in the activation of associated tyrosine kinases and thus signal transduction. [17]
2885
2886JAK2
2887
2888The GHR does not possess built-in tyrosine kinase activity and relies on associated kinases for signal transduction. The Janus kinase JAK2 provides a major component of signal transduction by GH. JAK2 associates with the GHR intracellular domain proline rich Box 1 motif via its amino terminal (JH5-7) FERM domain. JAK2 phosphorylates tyrosine residues on the associated GHR intracellular domain which provide docking sites for Src homology 2 (SH2) domain proteins, in particular STAT5a and 5b. The STATs 1, 3, 5a, and 5b are subsequently phosphorylated by JAK2, homo- or heterodimerise, translocate to the nucleus, bind to STAT responsive elements and activate transcription. [18]
2889
2890In the GHR unliganded state (unbound by the Gh molecule) it is thought that the JAK2 pseudokinase JH2 domain interacts with and autoinhibits the JH1 kinase domain resulting in an inactive JAK2. GH binding causes structural reorientation of the receptor GH domains , which results in a structural re-orientation of JAK2 and disruption of the ability of pseudokinase JH2 domains to inhibit the JH1 kinase domain, leading to JAK2 activation. There are several mechanisms for the termination of the JAK2 mediated signal which involve phosphatases, suppressors of cytokine signalling (SOCS) proteins that block signalling via their SH2 domains and receptor downregulation. [19]
2891
2892In essence GH binding to the GHR triggers activation of JAK2 which causes the GHR and JAK2 tyrosine phosphorylation which induces signaling systems. The primary signaling systems are:
2893
2894STATs (most notably STAT5b) ERKs PI3-kinase [23-25]
2895
2896GH-induced STAT5b activation requires receptor tyrosine phosphorylation and promotes gene transcription (eg., IGF-1, acid-labile subunit (ALS) of the IGF binding protein complex, SOCS proteins, hepatic P450 enzymes, and serine protease inhibitor[26–36]).
2897
2898Unlike STAT5b, GH-induced ERK and PI3K activation does not require the entire GHR cytoplasmic domain, but only JAK2 coupling [23,37,38 ,39-41]. ERK activity is critical for GH-induced c-fos transcription [42], enhances GH-stimulated proliferation [43], and mediates crosstalk with EGF signaling [44-46]. GH-induced PI3K activity is implicated in antiapoptosis and/or proliferation and likely contributes to GH-induced ERK, p70 S6 kinase, and phosphodiesterase activity [42,43,47-50].
2899
2900GH sensitivity is substantially affected by the abundance of GHR available for ligand engagement at particular target cells and tissues. Surface GHR availability is regulated at several levels, including transcriptional, post-transcriptional, and post-translational.
2901
2902For a thorough review of transcriptional and post-transcriptional events see references 51 & 52.
2903
2904GHR regulation at the post-translational will be reviewed herein.
2905
2906Movement of newly synthesized GHR to the cell surface
2907
2908GHR is synthesized as a non-glycosylated precursor that is transported from the endoplasmic reticulum (ER) to the Gogli apparatus. GHR dimerizes in the ER early in the process of biogenesis thus accounting for the receptor dimers detected at the cell surface even in the absence of GH engagement. [53, 60,61] In the process of transport through the Golgi, the GHR acquires carbohydrate in a characteristic fashion, in which high-mannose sugars added in the ER are ultimately removed during the transition from the early to late Golgi to yield the mature glycosylated GHR that populates the cell surface.
2909
2910JAK2 apparently associates with GHR early in the biosynthetic pathway and not only acts as a GHR chaperone as it makes its way to the surface but fosters GHR maturation [59,62]
2911
2912Studies suggest that in cells that lack JAK2 the nascent precursor GHR is a target for endoplasmic reticulum associated degradation (ERAD) and represent the first example of ERAD-associated cleavage of a cytokine receptor family member that stems from a lack of its cognate JAK. ERAD is a process whereby proteins that fail to fold properly or otherwise fail quality control mechanisms in the ER undergo retrotranslocation and proteasomal degradation in the cytosol [67–69]. JAK2, by virtue of its association with the GHR, rather than via its kinase activity, apparently "chaperones" the dimerized precursor so as to avoid quality control and proceed with efficient processing to mature GHR in the secretory pathway.
2913
2914How does JAK2 exert this chaperone effect? Multiple possibilities exist, including the notion that a receptor region that might otherwise be seen as defective or unfolded to the quality control apparatus is hidden by JAK2 binding. In a similar fashion, JAK2 binding might allosterically (i.e. shape change) alter a GHR site outside of the region that interacts with JAK2 to make that site appear less defective.
2915
2916In essence JAK2 association affects endoplasmic reticulum to cell surface GHR trafficking. In cells harboring GHR and JAK2 molecules that can associate, GHR moves from the ER to the Golgi, matures, and reaches the cell surface efficiently. In cells lacking JAK2 or with GHR molecules that cannot associate with JAK2 (by virtue of mutation of the receptor Box 1 region), GHR primarily undergoes endoplasmic reticulum-associated degradation (ERAD) while a small amount inefficiently matures and traffics to the cell surface (without association with JAK2).
2917
2918Proteolysis (degradation) of the GHR
2919
2920Over the last decade, it has become appreciated that GHR, like some other surface receptors, is a target for regulated sequential proteolysis, the first step of which (alpha-secretase cleavage) occurs in the proximal extracellular domain stem region 8–9 residues (depending on species) outside the plasma membrane [65,80,81]. This alpha- secretase cleavage results in loss of full-length GHR, appearance of a cell-associated transmembrane domain (TMD)/intracellular domain (ICD)-containing receptor fragment (the "remnant"), and a soluble GHR extracellular domain (ECD) (called GH binding protein (GHBP)[82,83]).
2921
2922GHR alpha- secretase cleavage is constitutive, but can be further induced in various cell types by a proteinkinase C activator (the phorbol ester, PMA), platelet-derived growth factor (PDGF), or serum [65,80,81,84– 87]. This cleavage is catalyzed mainly by the extracellular domain of the transmembrane metalloprotease, TACE (tumor necrosis factor-alpha converting enzyme; ADAM-17) [66,88].
2923
2924Importantly, inducible alpha- secretase cleavage likely regulates GH sensitivity; that is, GH-induced signaling is dampened after cells are exposed to stimuli that promote GHR alpha-secretase cleavage, but not in the presence of metalloprotease inhibitors or if noncleavable receptor mutants are expressed, suggesting that metalloproteolysis modulates GH responsiveness in part by regulating surface GHR levels [65,83,84].
2925
2926Further, recent in vivo experiments indicate that administration of bacterial endotoxin leads to downregulation of hepatic GHR abundance and hepatic insensitivity to GH at least in part by inducing receptor proteolysis, suggesting that this may constitute a physiologically-relevant mechanism of regulation of GH action [89]. Notably, GH itself does not promote GHR alpha-secretase cleavage; indeed, GH inhibits subsequent GHR proteolysis, apparently by altering GHR conformation, rather than by causing signaling [66].
2927
2928Recent studies have shown that the alpha-secretase-generated GHR TMD/ICD remnant is further cleaved by an enzyme activity termed gamma-secretase within the TMD, which liberates the ICD, a protein termed the "GHR stub" [87]. gamma-secretase consists of four molecules, including presenilin, which forms the aspartyl protease core and facilitates a process known as regulated intramembrane proteolysis (RIP) [90].
2929
2930In essence inducible alpha-secretase cleavage generates remnant, which is converted to stub by gamma-secretase. The stub is labile and can accumulate in either the cytosol or the nucleus; proteasome inhibition prevents stub degradation.
2931
2932In summary GHR undergoes sequential TACE and gamma-secretase cleavage. Surface GHR undergoes constitutive and inducible cleavage in the extracellular domain stem region by TACE in a process called "alpha-secretase" cleavage. This yields the shed GHBP and the GHR remnant. Remnant is then cleaved by gamma-secretase within the membrane to yield the GHR stub (soluble intracellular domain), which localizes to the nucleus, where it may affect gene expression.
2933
2934Surface GHR stability
2935
2936Once at the cell surface, the GHR could, in principle, achieve several fates. If engaged by GH, signaling is triggered and the receptor undergoes ligand-dependent downregulation. However, in the natural milieu, GH is released from the pituitary gland in a pulsatile fashion such that GH levels are quite low in periods between pulses. Thus, it is critical to understand factors that govern GHR abundance independent of GH. It is believed that mature GHRs are cleared from the cell surface by constitutive or inducible proteolytic shedding (discussed above) and by constitutive downregulation (discussed below).
2937
2938JAK2 affects the fate of the cell surface GHR and in cells lacking JAK2, the ratio of mature (cell surface):precursor GHR was substantially reduced in comparison to JAK2-replete cells [25,62]. This finding is partly explained by the chaperone effect of JAK2 during GHR biogenesis [63]. However, notable JAK2-dependent differences in the constitutive fate of mature GHRs are found as well [62]. In the context of a stable reconstitution system, the half-life (t1/2) of the receptor was estimated by anti-GHR immunoblotting after 0–4 h of treatment with cycloheximide (CHX) to inhibit new protein synthesis. The results of such a "CHX chase" assay indicated that the precursor GHR abundance dropped precipitously and to a similar degree with increasing duration of CHX treatment both in cells that did or did not express JAK2. For the mature receptor, however, there was a dramatic effect of JAK2. As measured by this assay, the GHR t1/2 increased from roughly 1 hr in cells that lack JAK2 to roughly 4 h in cells expressing JAK2 [62].
2939
2940Thus, in the absence of GH, it appears that, in addition to its role in shepherding the GHR through the secretory pathway and lessening the degree to which it is targeted for ERAD, JAK2 also extends the receptor's presence at or near the cell surface, presumably by interfering with constitutively active cellular machinery that functions to internalize and downregulate the receptor.
2941
2942In summary JAK2 association affects the constitutive (GH-independent) fate of surface GHR. In cells harboring GHR and JAK2 molecules that can associate, surface GHR is downregulated at a low constitutive rate and its half-life is long. In cells that lack JAK2 or have GHR and JAK2 molecules that cannot associate, GHR undergoes enhanced constitutive downregulation and exhibits a short half-life.
2943
2944GH-induced GHR downregulation
2945
2946Like many surface receptors, GHR undergoes important trafficking events in response to binding of its ligand. The net effect is substantial GH-induced receptor downregulation, which serves to limit or alter the receptor's signaling capacity and perhaps thereby further emphasize the physiologic effects of pulsatile GH release from the pituitary gland. Work as early as the 1970s–1980s and since that time suggested that GH-induced GHR downregulation proceeds via clathrin coated pit-mediated endocytosis and lysosomal degradation [91,98–100].
2947
2948GH ultimately causes its receptor to be degraded in lysosomes. However GH-induced receptor ubiquitination (inactivation by an attaching ubiquitin) depends on both JAK2 activity and the ability of the receptor to be tyrosine phosphorylated.
2949
2950Several binding partners have been shown to associate via their SH2 domains with the tyrosine phosphorylated intracellular domain [107–111, 114]. One of them, the protein tyrosine phosphatase, SHP-2, may contribute modestly to GH-induced GHR downregulation [108]. More recently, it has been appreciated that the SOCS family protein CIS (cytokine inducible SH2 domain-containing protein), which interacts with tyrosine phosphorylated GHR [109,110] and is likely linked to Cullin5-based E3 ubiquitin ligase complex that can recruit proteins to the proteasome for degradation [112], promotes GH-induced GHR internalization and thus can desensitize GH signaling [113].
2951
2952REFERENCES:
2953
2954[1] - [11] - UNUSED
2955
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2957
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3041
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3043
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3075
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3077
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3079
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3101
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3109
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3111
3112[114] W. Yi, S.O. Kim, J. Jiang, S.H. Park, A.S. Kraft, D.J. Waxman, S.J. Frank, Growth hormone receptor cytoplasmic domain differentially promotes tyrosine phosphorylation of signal transducers and activators of transcription 5b and 3 by activated JAK2 kinase, Mol. Endocrinol. 10 (1996) 1425–1443.
3113How GHRPs are cardio-protective
3114
3115The growth hormone secretagogues (GHS) are a family of synthetic compounds originally selected for their potent and specific effects on GH release. Nonetheless, it has been reported by us and other researchers that the GHS have also many extraendocrine actions, including those on energy metabolism and cardiovascular function. Ghrelin, the endogenous GHS, specifically binds to the GHS-R1a, a receptor that has been proposed to mediate the biological activities of endogenous and synthetic GHS.
3116
3117The activation of the GHS-R1a is not enough to explain the results that we have previously reported on the ability of hexarelin, a synthetic full agonist of the GHS-R1a, to protect the rat heart from the damage induced by the ischemia-reperfusion procedure. In fact, the GHS-R1a is not expressed in the myocardium, and ghrelin is much less effective than hexarelin in protecting the heart from ischemia-reperfusion damage.
3118
3119Moreover, it has also been demonstrated that in the cardiovascular system hexarelin and other GHS can also bind to the CD36, a scavenger receptor.
3120
3121Interestingly, a large similitude exists between the cardioprotective effects of hexarelin and those of some angiotensin-converting enzyme (ACE)-inhibitors. For this reason, we have decided to ascertain whether hexarelin, ghrelin and other synthetic GHS can modify the catalytic activity of serum and tissue ACE in rats and humans.
3122
3123Briefly, 10 ul of serum or tissue homogenate were incubated in presence of hippuryl-histidyl-leucine, a substrate of ACE that is cleaved to histidyl-leucine. The cleavage of the substrate was quantified by measuring the fluorescence at 365/495 nm (excitation/emission) in presence of orthophthaldialdehyde. Enalapril was chosen as reference ACE-inhibitor.
3124
3125Hexarelin (1 to 100 uM) dose-dependently blunted ACE activity up to about 50% in rat and human plasma and rat lung, heart and kidney. Enalapril (0.1 to 5 uM) dose-dependently inhibited ACE activity in serum and tissues up to 85%. Ghrelin (1 to 100 uM) did not significantly modify serum and tissue ACE activity at all the concentrations tested, whereas other synthetic GHS-R1a ligands demonstrated a dose-dependent inhibition of ACE activity ranging from 10 to 85%.
3126
3127We conclude that the protective actions of certain GHS on the cardiovascular system might be mediated, at least in part, by the capability of these compounds to modulate the ACE activity in the general circulation and locally in tissues.
3128
3129Source: Characterization of a Novel Extraendocrine Action of the Growth Hormone Secretagogues: Inhibition of Angiotensin-Converting Enzyme (ACE) Activity, A Torsello, M Ravelli, E Bresciani, I Bulgarelli, L Tamiazzo, S Caporali, V Locatelli,
3130
3131Dept of Experimental Med, Univ of Milano-Bicocca, Monza, Italy; Interdepartmental Ctr for Bioinformatics Proteomics, Univ of Milano-Bicocca, Monza, Italy
3132How much GH do we secrete in IUs?
3133
3134You see people on boards making all sorts of silly claims concerning how many ius we normally secrete.
3135
3136Did anyone catch the chart I posted in Post #558 which revealed that 24-hour GH secretion in males of ages 16 to 25 was just under 600mcg?
3137
3138Nutropin reveals that 1 iu of their GH is equal to 333 mcg, so a normal young male secretes about 2iu of GH a day.
3139
3140A normal male aged 26 to 35 secretes less than 1 iu of GH with the following age groups secreting less.
3141
3142Now the comparison isn't entirely accurate (Nutropin weight to how much GH ends up in plasma) but even if we add 50% to the value we are still talking about a normal male aged mid-twenties to mid-thirties secreting less than 2iu of GH a day.
3143
3144So do you think a middle aged male could benefit by a true (meaning accurate as opposed to Chinese generic product) 1-2iu increase in GH (such that can be created with just GHRP-6 alone)?
3145
3146From the stand point of healthy restoration to youthful levels, the answer is yes.
3147
3148For the lazy here is the chart from that post:
3149
3150Revisiting peptide timing, meals and GH release
3151
3152This is an interesting study done in cattle. Apparently cattle get one 2 hour feeding a day.
3153
3154So one hour before the meal GHRH by itself or GHRP-6 by itself worked better then when administered by itself one hour post-meal. That is what we would expect.
3155
3156In addition one hour pre-meal the GHRH + GHRP-6 produced a larger pulse of GH together. This we would also expect.
3157
3158What is surprising and interesting is that taking GHRP-6 + GHRH together one hour post-meal produced a pulse of GH basically equivalent to the pre-meal pulse. In other words the synergy of the two peptides over came the meal refractory effect (where either one administered alone was unable).
3159
3160Perhaps a similar effect takes place in humans... i.e. even when the stomach is full (1 hour post-meal) GHRH+GHRP-6 creates an undiminished GH pulse.
3161
3162ABSTRACT
3163
3164After a meal, somatotropes are temporarily refractory to growth hormone-releasing hormone (GHRH), the principal hormone that stimulates secretion of growth hormone (GH). Refractoriness is particularly evident when free access to feed is restricted to a 2-h period each day. GH-releasing peptide-6 (GHRP-6), a synthetic peptide, also stimulates secretion of GH from somatotropes. Because GHRH and GHRP-6 act via different receptors, we hypothesized that GHRP-6 would increase GHRH-induced secretion of GH after feeding. Initially, we determined that intravenous injection of GHRP-6 at 1, 3 and 10 ug/kg body weight (BW) stimulated secretion of GH in a dose-dependent manner.
3165
3166Next, we determined that GHRP-6- and GHRH-induced secretion of GH was lower 1 h after feeding (22.5 and 20 ng/ml respectively) than 1 h before feeding (53.5 and 64.5 ng/ml respectively; pooled (S.E.M.=8.5).
3167
3168However, a combination of GHRP-6 at 3 ug/kg BW and GHRH at 0.2 ug/kg BW synergistically induced an equal and massive release of GH before and after feeding that was fivefold greater than GHRH induced release of GH after feeding.
3169GF-1, GHRP, Testosterone, Trenbolone & Nandrolone Primer [entire thread...] (What you should read if you don't want to be a beginner)
3170
3171I think it's important to start off by visualizing an interesting distinction between peptide hormones such as insulin and growth hormone and the peptide hormone IGF-1. Insulin and Growth Hormone have their own specific storage vesicles within specialize cells or tissue where they may sit and await a command for release. IGF-1 has no such storage compartment. Stated succinctly, Growth Hormone and Insulin are held in storage compartments before release whereas there is no such storage compartment for IGF-1.
3172
3173This distinction has the consequence that circulating growth hormone and insulin are low under non-stimulated conditions. As a result the signal to the body to go on and do something as a command from growth hormone or insulin derives almost exclusively from controlling the entry rate of those peptide hormones into circulation. When these peptides can be coaxed from their storage areas into circulation they have the opportunity to transmit that signal or command to target tissue. As a consequence of having their own specific storage sites, the signal level that growth hormone is capable of bringing or the signal level that insulin is capable of bringing is primarily regulated by controlling their entry into circulation. It is not controlled by their rate of synthesis.
3174
3175The synthesis of insulin and growth hormone need not be rapid. The concentration of these two hormones released into circulation is not limited by their rate of synthesis. The body seems to always have plenty at the ready. Enhancement of growth hormone or insulin synthesis is never something we need be immediately concerned.
3176
3177The signaling commands that insulin and growth hormone bring are only effective if target cells express specific receptors to receive the hormones and capture that signal. So it is rapid changes in hormone concentration together with receptive tissue that initiates the body to do something.
3178
3179All of this is distinct from the IGF-1 system. There is no gland or storage vesicle for IGF-1. Without a storage component housing complete and ready for release IGF-1, it becomes more dependent on various components to convey it's signaling command. The synthesis rate is important and IGF-1's appearance in circulation is slow and dependent on it's synthesis rate and on how the body chooses to maintain, discard or deliver it.
3180
3181For IGF-1 the circulation becomes the extracellular storage area and it is maintained, discarded or delivered based on it's attachment to binding proteins or the ternary complex - Acid labile subunit. These binding proteins and the ternary complex are in a way virtual storage compartments as they maintain IGF-1. The total serum level of IGF-1 depends on both the synthesis rate and the capacity and stability of the aforementioned complexes which act as a buffer.
3182
3183Growth hormone and Insulin are transmitted to target tissue in a pulse through the bloodstream from their storage units. The bloodstream is merely a means of transmission. For IGF-1 it must rely on the bloodstream to serve as it's reservoir.
3184
3185IGF-1 also differs from growth hormone and insulin in that IGF-1 is produced in tissue throughout the body from muscle to brain (even though the liver remains the primary source). As a consequence IGF-1 is best thought of as an autocrine or paracrine IGF1 system even though circulating IGF-1 is often characterizes as endocrine or systemic. In the IGF-1 autocrine/paracrine system local signaling is highly dependent on the local synthesis and release of IGF acting on the producer cell, or its neighbours, by local diffusion. Furthermore local production of specific binding proteins may attract circulating IGF-1 and sequester them, either localizing them to target cells or retaining them in the producer tissue in an extracellular pool from which that cell population may eventually draw from. Proteases which cut off the IGF-1 from the attached binding proteins would free IGF-1 and make them available to the cellular receptors. The appearance of proteases to do this most likely comes from release & activation from damaged cells such as damaged muscle cells from resistance exercise.
3186
3187IGF-1 once cut off from the local binding protein could either join a local pool of free IGF-1 for local activity or escape the local environment and enter circulation. Binding proteins in circulation would reattach to and buffer the paracrine IGF-1 to prevent the locally generated IGF-1 signaling to spread to other tissues.
3188
3189Blood tests for circulating IGF-1 do not measure the activity of IGF-1. They are actually measuring the storage reserve. Whereas blood tests for growth hormone and insulin need to be timed correctly they do not measure storage but reveal the amount of peptide in route to activity at that point in time.
3190
3191Endocrine vs paracrine secretory systems. a) The classical endocrine system, with a gland reserve of hormone and transmission of bursts of hormone release in the bloodstream to stimulate target tissues that selectively express the relevant hormone receptor. b) The endocrine IGF1 system has no primary gland store, but the peptide is constitutively produced from many tissues, with liver being a major source. The bloodstream serves as the IGF reservoir, retaining IGF1 complexed with binding proteins (BPs) and acid labile subunit (ALS) to prevent rapid elimination. A small proportion of free IGF dissociated from these complexes can bind IGF receptors in the target tissues. c) IGF1 is also generated locally in many tissues which are also targets for its action. They also produce binding proteins which may block or enhance IGF1 local action. BP and ALS in the circulation now serve to capture and buffer any locally produced IGF1 escaping to signal elsewhere.
3192IGF-1 - Primer part 2 (IGF-1 as a regulator of Skeletal Muscle Hypertrophy and Atrophy)
3193
3194Let's start simply. Hypertrophy results from an enlargement. It is an increase in the size of something that exists and in regard to hypertrophy in skeletal muscle it is simply an increase in the size of existing muscle fibers. Hypertrophy does not refer to an increase in the number of pre-existing muscle fibers. IGF-1 is pro-hypertrophy meaning it promotes hypertrophy. It can play a role in the rare occurrence of hyperplasia which is an increase in the number of pre-existing muscle fibers. However most muscle mass increases in everyone from professional bodybuilders to the weekend hobbiest comes from hypertrophy so much so that hyperplasia is best left out of the anabolic discussion. Most people like the sound of the word "hyperplasia" but it is hypertrophy that does all the heavy lifting.
3195
3196When free IGF-1 or rather the mature form of IGF-1 binds to it's receptor it triggers a series of events within a cell. This series is called signaling and the path that the signal takes is called a pathway. There are many components or elements within a cell that are capable of impacting that signal. These elements can play the role of handing the signal off to another element or they could somehow be an element that takes into consideration some sort of state... maybe a nutritional state... so they are in a way sensors... and based on what they sense about some state decide between which fork in the pathway the signal should be transmitted. Some elements amplify the signal. Some elements may inhibit the signal. Some elements play a small role while other play a huge role. The ones that play the huge role often receive the signal and based on that initiate events that will lead to gene transcription. Most elements in a cell aren't even called upon to play a part in a signaling cascade while some show up repeatedly in many varied contexts. Last but not least an element may be capable of residing in both the cytoplasm and nucleus and based on where it is currently residing activates distinct functions. Maybe if it is in the nucleus it is promoting but if it is in the cytoplasm it is inhibiting the signaling.
3197
3198Again a pathway is a series of these elements and as a collective they are studied.
3199
3200IGF-1's pro-hypertrophy activity primarily emanates from its ability to activate the Phosphoinositide 3-kinase (PI3k)/Akt signaling pathway. The introduction of names for our elements need not confuse. PI3k is an element and so is Akt. The pathway flows fromIGF-1 binding to it's receptor and triggeringPI3k which transfers the signaling to Akt. Now there are minor elements between these two but they are the major elements and so the pathway is named after them.
3201
3202Akt is a very important element. It can trigger protein synthesis and at the same time block up-regulation of the key mediators of muscle atrophy - MuRF1 and MAFbx . It triggers protein synthesis more directly by signaling to mTOR.
3203
3204It does the latter (prevention of atrophy) by preventing FOXO from moving to the nucleus and this has the ultimate effect of blocking the up-regulation of those muscle atrophy elements MuRF1 and MAFbx. MuRF1 and MAFbx cause atrophy by "spray painting" parts of proteins so that proteasomes can locate those areas and degrade the protein.
3205
3206Under normal growth conditions, FOXOs are inactivated and not required for the survival of cells. Growth factors (such as insulin & IGF-1) inhibit FOXO activation whereas ROS, DNA-damage, energy stress activate it
3207
3208The point I appeared to be making is that there are some signals through FOXO that I want and some that I may not want. There is no inherent good or bad in inhibiting FOXO. Stopping FOXO from excessively triggering the atrophy of my muscles is good. Stopping FOXO so that things that need to be eliminated aren't isn't a good thing.
3209
3210So back to the main topic... MuRF1 is really good at marking the thick muscle fibers for destruction and so by blocking MuRF1 activation IGF-1 through trigger Akt helps prevent the break down of the thicker parts of muscle.
3211
3212IGF-1 may also strongly inhibit the anti-hypertrophy effects of myostatin. Myostatin activates two elements Smad2 and Smad3. It actually binds to a receptor complex made up of ACTRII and ALK4 or ALK5 and in so doing activates Smad2 and Smad3. Once activated these two move to the nucleus and from there they are able to inhibit Akt which ends up inhibiting TORC1. This inhibition feeds back and allows myostatin to activate even more Smad2. Akt remember does two things. It promotes protein synthesis through mTOR and it inhibits atrophy. When it does this in myoblast and myotubes this promotes anabolism and muscle mass. When Myostatin inhibits the activation of Akt in myoblasts and myotubes it hinders anabolism and muscle mass. To some extent TGFB may also activate SMAD2 & 3.
3213
3214Now the signaling pathway Akt/mTOR/p70S6 in addition to increasing protein synthesis also mediates both differentiation in myoblasts and hypertrophy in myotubes.... basically the making and enlarging of muscle. If left to it's own devices myostatin would cause decreases in the diameters of myotubes.
3215
3216IGF-1 dominantly blocks the effects of myostatin in myoblasts and myotubes. I didn't make up the word "dominate" it was used by the authors of Myostatin reduces Akt/TORC1/p70S6K signaling, inhibiting myoblast differentiation and myotube size, Anne Ulrike Trendelenbur, American Journal of Physiology - Cell Physiology Published 1 June 2009 Vol. 296 no. 6, C1258-C1270 : .Treatment of human myoblasts with myostatin for 24h decreased phosphorylation [i.e. activation] of Akt by up to 50%. In addition to inhibiting Akt, myostatin decreased phosphorylation of p70S6 kinase and the pro-atrophy transcription factor FoxO1, both of which are normally phosphorylated by Akt.However, Akt, p70S6 kinase, and FoxO1 phosphorylation were restored by treatment with IGF-1, indicating that IGF-1/Akt signaling is dominant over myostatin/Smad/Akt inhibition.
3217
3218The authors also mentioned in partially non-published data that "In addition to restoring Akt phosphorylation, IGF-1 also partially rescues the differentiation of myostatin-treated myoblasts, as determined by measuring fusion index, diameters (data not shown), and CK (Creatine kinase) activity."
3219
3220So IGF-1 gets this signaling pathway going by stimulating PI3k/Akt which leads to the elements that can induce protein synthesis. It is a serious over simplification but resistance exercise leads to activation of the PI3k/Akt pathway by directly inducing muscle expression of IGF-1. - DeVol DL,Activation of insulin-like growth factor gene expression during work-induced skeletal muscle growth, Am J Physiol 259:E89–95 1990 & Yan Z, Insulin-like growth factor immunoreactivity increases in muscle after acute eccentric contractions, J Appl Physiol 74:410–414 1993 . This is sufficient to induce hypertrophy in muscle both in vitro - Vandenburgh HH, Insulin and IGF-I induce pronounced hypertrophy of skeletal myofibers in tissue culture, Am J Physiol 260:C475–484 1991and later in vivo - Musaro A, Localized IGF-1 transgene expression sustains hypertrophy and regeneration in senescent skeletal muscle, Nature Genet 27:195–200 2001 & Coleman ME,Myogenic vector expression of insulin-like growth factor I stimulates muscle cell differentiation and myofiber hypertrophy in transgenic mice, J Biol Chem 270:12109–12116 1995
3221
3222Activation of Akt is sufficient to induce hypertrophy in vivo. In the study cited for this sentence, acute activation of Akt for two to three weeks was found to be sufficient to induce a doubling in the size of skeletal muscle... this increase occurred in the average cross-sectional are of individual muscle fibers brought about by an increase in the TORC1/p70S6K protein synthesis pathways. - Lai K-MV,Conditional activation of Akt in adult skeletal muscle induces rapid hypertrophy, Mol Cell Biol 24:9295–9304 2004.
3223
3224I should note that although IGF-1 activates mTOR and p70S6k downstream of PI3K/Akt activation, amino acids can activate mTOR directly bringing about a subsequent stimulation of p70S6K activity.
3225
3226I discuss how important the element eIF2B is to protein synthesis and how GSK3beta blocks eIF2Bs activity. Well if GSK3beta is inhibited there is also enhanced myotube formation and muscle-specific gene expression leading to differentiation.
3227
3228Although all of this may seem to be a bit much for this post I bring it up only to point out that IGF-1 inhibits GSK3beta which is a different mechanism by which hypertrophy is induced and myoblast differentiation promoted.
3229
3230To be continued... but I think I have given a sufficient little primer on IGF-1 and intracellular signaling. IGF-1 is anabolic and anti-catabolic. It inhibits myostatin and GSK3beta and promotes both protein synthesis and differentiation.
3231INFO ON MGF USE
3232
3233To quickly summarize the difference in function, MGF stimulates muscle stem cells (satellite cells) to reenter the cell cycle and proliferate, whereas IGF-1 is necessary for the differentiation of newly generated muscle precursor cells into myoblasts and myofibers.See material from Goldspink posted earlier in this thread at: Post #158 Mechanical Signals, IGF-I Gene Splicing, and Muscle Adaptation
3234
3235Growth Hormone bound to its receptor in the liver activates the STAT5b signaling pathway which promotes movement of that activated signaling protein to the nucleus where it induces transcription of the IGF-1 gene. From studies in mice and humans, it is evident that GH induces expression of both the endocrine form of IGF-1, the muscle form of IGF-1 and MGF. 1 Mice deficient in GH (lit/lit mice) respond to administration of GH with an acute increase in MGF, but not IGF-1, in skeletal muscle, although IGF-1 in liver is increased. 2 However the precise mechanism by which GH has distinct effects on IGF-1 and MGF expression in muscle is not completely known.
3236
3237What is known is that in response to stretch overload and the presence of growth hormone combined gene transcription in muscle and its subsequent "blueprint" assembly" are induced to create mechano growth factor (MGF also known as IGF-1Ec in humans or IGF-1EB in mice) instead of muscle IGF-1.
3238
3239How does the behavior of IGF-1 and MGF differ?
3240
3241"MGF is a non-secreted form of IGF-1 that can be found in the nucleus of cells in culture or in a perinuclear location in hippocampal cells after ischemia (restriction in blood supply)".
3242
3243In other words MGF never leaves the cell it was created in. For emphasis I quote from another source:
3244
3245"...MGF... is not normally secreted."
3246
3247Geoffrey Goldspink has written "that MGF increases myoblast proliferation via a different signalling pathway" then IGF-1.
3248
3249To reiterate & expand upon this concept I quote from another source:
3250
3251"IGF-1 isoforms differ in the signaling pathways they activate. By over-expressing IGF-1Ea and MGF in muscle, it has been shown that both isoforms can activate IGF-1R and AKT phosphorylation. In addition, MGF was shown to induce phosphorylation of ERK, a property not shared with IGF-1Ea."
3252
3253So IGF-1 and MGF work through different pathways not receptors. There is only one receptor, IGF-1-receptor (also insulin, IGF-II & hybrid receptors which are not relevant to this discussion). There is no MGF receptor. The reason why it would be nonsensical to have an MGF receptor is that MGF does not leave the cell.
3254
3255This contrasts with IGF-1 which is released from the liver into circulation and which is created in muscle and translocates to the cell surface. Both events result in IGF-1 binding to the IGF-1 receptor.
3256
3257So what happens in plain language please?
3258
3259During the process of gene transcription pieces of DNA are transcribed and then spliced together by RNA and this code is taken to the ribosomes where the peptide is manufactured. In splicing MGF there is a subtle frame shift such that the right side of the code is a little different then IGF-1. Everything else is identical.
3260
3261This subtle difference means that when MGF & IGF-1 are manufactured by the riboomes MGF MUST because of the signal pull that is part of its make up, translocate to the Nucleus of the cell and more specifically the Nucleolus.
3262
3263IGF-1 because of its makeup MUST move to the cytoplasm where it forms a pool of IGF-1 which will transloacte to the cell membrane where it will bind w/ an IGF-1 receptor.
3264
3265MGF has NO receptor. It does not need it to mediate events. Too many times people think that a lock/key ligand/receptor is needed to intiate signals. That is not always true especially when proteins move to the nucleus.
3266
3267MGF is NEVER found in circulation. It is produced in a muscle cell as described and it will act there always.
3268
3269IGF-1 however does circulate. It is produced in the liver and secreted into the blood stream. If it is made in muscle tissue or in local tissue it makes its way to the surface and can bind to a receptor on that cell or nearby cells. The latter is how muscle made IGF-1 can effect nearby bone growth.
3270
3271In lab experiments with MGF they usually do one of two things. One they use a viral vector of MGF cDNA to increase the cDNA of MGF in the cell so that more MGF is made internally. When they do this they get a 25% increase in muscle in a three week period. If they use the same approach to get IGF-1 to express itself from within they get less muscle growth (15%) and it takes 4 months.
3272
3273The second approach is to actually inject MGF into a cell (i.e. penetrate the cell membrane). Unfortunately for scientists this also invokes a damage repair function in cells so it is difficult to actually attribute all of the benefits that ensue to MGF.
3274
3275You follow neither of these approaches when you inject MGF or Peg MGF.
3276
3277MGF is identical to IGF-1 in chemical makeup on the leftside of the peptide. This allows it to bind with IGF-1 receptors should it ever be injected or find itself outside of the cell. However because of the difference in right-side structure MGF is incapable of binding to IGF-1 binding proteins (which would prolong its life).
3278
3279MGF has a very short half-life in blood plasma. If it is pegylated it has a longer half-life. I do not know the extent to which pegylation reduces binding affinity but it probably does to some extent depending on where it is pegylated.
3280
3281Injecting Peg MGF will, if it survives, probably bind to an IGF-1 receptor. If it does so it activates the IGF-1 signaling pathways just as IGF-1 would.
3282
3283I do not have any data on how strongly MGF will bind to IGF-1 receptors. A pegylated MGF is small enough to penetrate the vascular wall and travel systemically. It will not be confined to the area injected as IGF-1 bound to IGF-BindingProtein3 bound to Acid laibile subunit (i.e. the ternary complex) will. Thats why injecting large amounts of MGF brings vacularization, pumps, glucose uptake, in essence insulin-like activity....because it is behaving as IGF-1...and doing so in systemic fashion.
3284
3285Some science (derived from ref:5) followed by both a reiteration and an elaboration on my part.
3286
3287The IGF-1 gene consists of 6 exons (DNA bases that are transcribed into mRNA and eventually code for amino acids in the proteins), separated by 5 introns (DNA bases, which are found between exons, but are not transcribed). Transcription is controlled by alternate use of two upstream promoters and starts at several transcription start sites located in exons 1 and 2. Together, alternate promoter usage and alternative splicing at the 5' and 3' ends of the gene generate several distinct mRNAs depending on their exon sequences, which code for three isoforms of precursor IGF-1.
3288
3289Note: The notation 5' and 3' refer to the direction of the DNA template in the chromosome and is used to distinguish between the two untranslated regions (grey).
3290
3291These isoforms have characteristic N-terminal signal peptide sequences and C-terminal extension (E) peptide domains. Exons 1 and 2 and part of exon 3 encode the signal peptides. The remainder of exon 3 and exon 4 encode the mature IGF-1 peptide and the proximal part of the E peptide, which are shared by all isoforms. Splicing of exon 4 to exon 6 generates the predominant transcript IGF-1Ea. Splicing of exon 4 to exon 5 generates IGF- 1Eb, which encodes an isoform with 47 distinct amino acids in the E domain. When part of exon 5 is spliced to exon 6, the IGF- 1Ec (IGF-1EB in mouse) variant is generated. In this case, a frame-shift occurs in exon 5 followed by premature transcription stop in exon 6 that results in a stretch of 25 amino acids unique to this variant.
3292
3293As a result these templates produce in cellular ribosomes IGF-1 peptide forms that differ in amino acid structure in the E peptide region. This results in different C-terminal regions for the IGF-1 & MGF peptides. MGF BECAUSE of its C-terminal sequence, upon "birth" becomes rapidly localized in the nucleus. It is the carboxy portion which draws either MGF or the altered portion to the nucleus rather than to the cell membrane.
3294
3295"We found that the isoform of the human IGF-I precursor encoded by exon 5 [MGF] localized to the nucleus and strongly to the nucleolus. Precursors containing exon 6 or the upstream portion of exon 5 did not...The findings are consistent with the presence of a nuclear and nucleolar localization signal situated in the C-terminal part of the exon 5-encoded domain."
3296
3297MGF is an autocrine growth factor, and this is THE different signaling pathway...a pathway that does not involve any receptor. The action of MGF via this pathway is one of promoting myoblast proliferation.
3298
3299However MGF maintains a dual action. It "activates the muscle stem cell pool through its C-terminal domain (encoded in exons 5 and 6) as mentioned above AND according to the various studies by Geoffrey Goldspink "increases anabolic effects as the result of its IGF-I receptor binding domain (encoded in exons 3 and 4), which all the IGF-I genes possess."
3300
3301The unaltered portion of MGF is still capable of binding to the IGF-Receptor. The altered carboxy portion renders MGF incapable of binding to the IGF-1-Binding proteins BUT it possesses the ability to bind to the IGF-1-Receptor via the unaltered side.
3302
3303So what if MGF is injected into plasma? Presumably it would bind to the IGF-1-Receptor and initiate the AKT signaling pathway which will stimulate cell growth signals. In other words MGF stops being MGF and behaves like IGF-1 in initiating anabolic events. But it has been shown but is not yet fully understood that MGF is capable of AKT phosphorylation (an IGF-1-IGF-1-receptor mediated event) without ever coming in contact with the IGF-1-receptor.
3304
3305This brings up an interesting point. MGF seems to be capable of performing both its unique duties and those of IGF-1 as well (at times).
3306
3307What about studies that inject MGF into subjects?
3308
3309Actually they don't do it that way.
3310
3311"One of the methods we used to establish the biological action of MGF was to engineer a gene into which its cDNA was inserted into a vector. To our surprise a single intramuscular injection into a mouse muscle resulted in a 25% increase in mean muscle fibre cross section area within three weeks." - Goldspink G, Yang SY. Method of treating muscular disorders, United States Patent. Patent No US 6,221,842 B1, Apr 24, 2001.
3312
3313This contrasts with, "similar experiments carried out using the systemic or liver type of IGF-I in an adenoviral vector under the control of a muscle regulatory sequence. This took four months to produce a 15% increase and is probably due to the anabolic effect of IGF-I, which is common to all the splice variants." - Barton-Davis E, Shoturma DI, Musaro A, et al. Viral mediated expression of insulin-like growth factor-I blocks the aging-related loss of skeletal muscle function. Proc Natl Acad Sci USA 1998;95:15603
3314Testosterone blunts IGF-1 inhibition of GH
3315
3316Rexanator led me to Testosterone Blunts Feedback Inhibition of Growth Hormone Secretion by Experimentally Elevated Insulin-Like Growth Factor-I Concentration, Johannes D. Veldhuis, Stacey M. Anderson, Ali Iranmanesh and Cyril Y. Bowers, The Journal of Clinical Endocrinology & Metabolism Vol. 90, No. 3 1613-1617, 2005, where they found:
3317
3318"...supplementation of a high dose of Te in middle-aged and older men attenuates IGF-I feedback-dependent inhibition of nadir and peak GH secretion."
3319
3320The results of this study were confirmed in a recent study published this month:
3321
3322Testosterone Supplementation in Older Men Restrains Insulin-Like Growth Factor’s Dose-Dependent Feedback Inhibition of Pulsatile Growth Hormone Secretion,Johannes D. Veldhuis, Daniel M. Keenan, Joy N. Bailey, Adenborduin Adeniji, John M. Miles, Remberto Paulo, Mihaela Cosma and Cacia Soares-Welch,The Journal of Clinical Endocrinology & Metabolism Vol. 94, No. 1 246-254, 2009
3323
3324Background: Pulsatile GH secretion declines in older men. The causal mechanisms are unknown. Candidates include deficient feedforward (stimulation) by endogenous secretagogues and excessive feedback (inhibition) by GH or IGF-I due to age and/or relative hypoandrogenemia.
3325
3326Hypothesis: Testosterone (T) supplementation in healthy older men will restrain negative feedback by systemic concentrations of IGF-I.
3327
3328Subjects: Twenty-four healthy men (ages, 50 to 75 yr; body mass index, 24 to 30 kg/m2) participated in the study.
3329
3330Methods: We performed a prospectively randomized, double-blind, placebo-controlled assessment of the impact of pharmacological T supplementation on GH responses to randomly ordered separate-day injections of recombinant human IGF-I doses of 0, 1.0, 1.5, and 2.0 mg/m2.
3331
3332Analysis: Deconvolution and approximate entropy analyses of pulsatile, basal, and entropic (pattern-sensitive) modes of GH secretion were conducted.
3333
3334Results: Recombinant human IGF-I injections 1) elevated mean and peak serum IGF-I concentrations dose-dependently (both P < 0.001); 2) suppressed pulsatile GH secretion (P = 0.003), burst mass (P = 0.025), burst number (P = 0.005), interpulse variability (P = 0.032), and basal GH secretion (P = 0.009); and 3) increased secretory pattern regularity (P = 0.020).T administration did not alter experimentally controlled IGF-I concentrations, but it elevated mean GH concentrations (P = 0.015) and stimulated pulsatile GH secretion (frequency P = 0.037, mass per burst P = 0.038). Compared with placebo, T attenuated exogenous IGF-I’s inhibition of GH secretory-burst mass (P < 0.038) without restoring pulse number, basal secretion, or pattern regularity.
3335
3336Conclusion: The capability of systemic T to mute IGF-I feedback on pulsatile GH secretion suggests a novel mechanism for augmenting GH production.
3337Adipose Visceral Fat Negatively correlated with effectiveness of GHRH & GHRP-2
3338
3339Joint Regulation of Pulsatile GH Secretion by Estradiol, Dihydrotestosterone and Abdominal Visceral-Fat Mass in Healthy Older Men: A Paradigm of Aromatase and 5-alpha-Reductase Types I and II Blockade, J Veldhuis, K Mielke, J Miles, C Bowers
3340
3341Background Dissecting the relative roles estradiol (E2), 5-alpha-dihydrotestosterone (DHT), and abdominal visceral fat mass (AVF) in the specific mechanistic regulation of GH secretion remains difficult. In part the impasse reflects interdependency among Te-derived sex steroids due to interconversion by aromatization and 5-alpha reduction, and in part the separate but interactive nature of hypothalamo-pituitary pathways driving (GHRH and ghrelin/GHRP-2) or inhibiting (somatostatin-14, SS-14) GH secretion.
3342
3343Subjects Eleven healthy men ages 61-79 yr.
3344
3345Methods Subjects were each studied 5 times fasting on separate mornings in random order. Secretagogues comprised saline, SS-14 withdrawal, bolus GHRH or GHRP-2, and L-arginine infusion followed by bolus injection of both peptides (to estimate maximal pituitary GH secretion).
3346
3347AVF (adipose visceral fat) estimates were made by single-slice CT scan.
3348
3349Outcomes
3350
3351Regression analyses revealed that unstimulated GH secretion was most strongly determined by AVF (standardized coefficient, sc = -0.648, P = 0.031).
3352
3353SS-14 withdrawal-induced GH release tended to correlate with E2 (sc = +0.589, P = 0.071).
3354
3355The response to GHRH bolus was strongly determined by AVF (sc = -0.712, P = 0.014) and weakly by DHT(sc = +0.596, P = 0.053).
3356
3357In contrast, GH peaks induced by GHRP-2 and triple-secretagogue infusions were associated with only AVF(sc = -0.689, P = 0.019).
3358
3359Summary E2 and DHT are positively predictive of GH responses to specific, rather than all, secretagogues, whereas AVF is negatively correlated with GH responses to all secretagogues except SS-14 withdrawal.
3360
3361Conclusion Sex steroids specifically and visceral adiposity generally determine peptide-selective drive of GH secretion in healthy older men. The precise pathways that mediate the interdigitating mechanisms are not known.
3362Here is another way to compare GHRPs & GH dosing vs effect
3363
3364This study * caught my attention because it examined the pharmacokinetics of GHRP-2 and in so doing compared it to synthetic GH administration.
3365
3366Basically they found 1mcg/kg of GHRP-2 half as effective as 43mcg/kg of synthetic GH...they found a linear relationship and therefore they conjectured that 2mcg/kg of GHRP-2 would be as effective as 43mcg/kg of synthetic GH.
3367
3368However the studies participants were prepubescent children of short stature so we should use their weights. Googling revealed that 40lbs would be a decent approximation of such a young undersized male child. That converts to about 18 kilograms.
3369
3370For synthetic GH that would mean the children received 43mcg * 18kg = 774mcg of GH.
3371
3372Nutropin reveals that 1 iu of their GH is equal to 333 mcg so that equates to aproximately 2.3iu of GH.
3373
3374For GHRP-2 that would mean the children received 1mcg * 18kg = 18mcg of GHRP-2.
3375
3376Using the studies statement that 2mcg/kg of GHRP-2 equalled the synthetic GH dose we arrive at 2mcg * 18kg = 36mcg of GHRP-2 equally 2.3iu of synthetic GH...or further extrapolation 100mcg of GHRP-2 approximately = 6iu of synthetic GH.
3377
3378I think the above extrapolation is too liberal for adults & thus flawed. So lets be real conservative in our approach and recognize that the studies used saturation doses (1mcg/kg). For adults I would like to stick with the definition of saturation dose of 1mcg/kg... and use that for adults so for a 100kg man that equals 100mcg of GHRP-2. That would mean a single 100mcg dose of GHRP-2 would equal 1.15iu of synthtic GH.
3379
3380All this approach assumes is that the saturation dose for children produced the equivalent of 1.15iu of synthetic GH therefore the saturation dose for adults will do the same.
3381
3382So 3 100mcg doses of GHRP-2 per day will conservatively equate to (1.15 x 3) about 3.5iu of synthetic GH. Note that if the average weight of the study children were really 50 pounds then this 3.5iu estimate becomes 4.2ius of synthetic GH.
3383
3384So it is probably not unrealistic to figure that 100mcg of GHRP-6 dosed three times a day will yield the approximate equivalent of 3.5 to 4 ius of synthetic GH per day in a young adult male.
3385
3386    Pharmacokinetics and Pharmacodynamics of Growth Hormone-Releasing Peptide-2: A Phase I Study in Children Catherine Pihoker, Gregory L. Kearns, Daniel French and Cyril Y. Bowers, The Journal of Clinical Endocrinology & Metabolism 1998 Vol. 83, No. 4 1168-1172
3387
3388Abstract
3389
3390Administration of GH-releasing peptide-2 (GHRP-2) represents a potential mode of therapy for children of short stature with inadequate secretion of GH. Requisite information to determine the dosing route and frequency for GHRP-2 consists of the pharmacokinetics (PK) and pharmacodynamics (PD) for this compound, neither of which have been previously evaluated in children. The purpose of this study was to characterize the PK and PD of GHRP-2 in children with short stature. Ten prepubertal children (nine boys and one girl; 7.7 ± 2.4 yr old) received a single 1 µg/kg iv dose of GHRP-2 over 1 min, followed by repeated (n = 9) blood sampling over 2 h. GHRP-2 and GH were quantitated by specific RIA methods. PK parameters were calculated from curve fitting of GHRP-2 and GH vs. time data. Posttreatment plasma GH concentrations (normalized for pretreatment values) were used as the effect measurement....
3391
3392Discussion
3393
3394The pharmacokinetics of GHRP-2 found in our cohort of pediatric patients are similar to those previously reported in healthy adult volunteers after iv administration of the peptide (3). A comparison of the maximum GH response observed after GHRP-2 administration between these two studies revealed similarities in both the magnitude (i.e. mean values = 44 µg/L in children vs. 55 µg/L in adults) and time of maximal response (i.e. average values = 45–60 min for both). The GH responses observed after iv or sc GHRP-2 are also similar to those previously reported after the parenteral administration of GHRP-6, GHRP-1, or GHRH (3, 4, 23, 24).
3395
3396To our knowledge, our data represent not only the first report of GHRP-2 pharmacokinetics in pediatric patients, but also the first pharmacodynamic assessment of this peptide. Comparison of the serum concentration vs. time profiles for both GHRP-2 and GH in our subjects reveals an equilibration delay in the attainment of peak GH response, a period that we believe corresponds to the time course of GHRP-2 action. This assertion is supported in part by the consistent observation of an equilibration delay between the serum concentrations of GHRP-2 vs. effect (i.e. change GHt) curves, reflected by the production of a counterclockwise hysteresis and our success in using the sigmoid Emax model to effectively determine the pharmacodynamic parameters for GHRP-2. As previously reported by Holdford and Sheiner (22), the successful application of this pharmacodynamic model suggests both linearity and predictability in the drug concentration vs. effect relationship. Given the fact that GH is a proximate biological marker of GHRP (and presumably, GHRP-2) activity (23, 24), our assumptions entailed in the pharmacodynamic analysis of our data appear valid and reflective of the expected pharmacological response of GHRP-2.
3397
3398Despite the apparent differences in serum GH pharmacokinetics reported after exogenous administration of the hormone (25) as opposed to the administration of GH secretagogues (26, 27, 28, 29, 30), both the pharmacokinetic and pharmacodynamic data from our study can be used to address the potential therapeutic efficacy of GHRP-2 in pediatric patients with GH insufficiency. First, the mean AUC for GH after the iv administration of a single 1 µg/kg dose of GHRP-2 (i.e. 50.7 ng/mL•h) was approximately 50% of the AUC at steady state (i.e. 114.2 ± 32.7 ng/mL•h) previously reported in a study of pediatric patients who received daily sc doses of 43 µg/kg methionyl GH (25). If one assumes linearity in the dose-response relationship for iv GHRP-2, administration of a single 2 µg/kg iv dose would be expected to produce an AUC for GH that would be virtually identical to that observed under steady state conditions after sc administration of the currently recommended daily doses of recombinant human GH (25), doses that have been shown to produce acceptable rates of linear growth in children who are GH deficient (30). Second, both the Cmax (mean, 50.7 ng/mL) and Emax values for GHRP-2 in our patient cohort (mean GH, 67.5 ng/mL) actually exceeded the average Cmax values for GH (37.6 ± 11.6 ng/mL; range, 17.6–49.5 ng/mL) after a single sc dose of 0.1 mg/kg methionyl GH to GH-deficient children (25). Finally, the EC50 for GHRP-2 in our study cohort (1.1 ± 0.6 ng/mL) was substantially less than the Cmax value (7.4 ± 3.8 ng/mL). This particular finding not only supports the adequacy of the 1 µg/kg iv dose of GHRP-2 in producing a desirable biological effect, but also suggests that extravascular administration of this peptide by a route that could be associated with up to a 50% reduction in bioavailability may still produce an acceptable increase in the serum GH concentration sufficient to initiate and sustain a desired growth response. This hypothesis is being tested by our group in dose-ranging studies of oral and intranasal GHRP-2 that are currently underway.
3399
3400In conclusion, both the pharmacokinetics and pharmacodynamics of iv administered GHRP-2 in short children are predictable and reflective of the potential for therapeutic application of this peptide. The data produced in this investigation will enable the selection of GHRP-2 doses for future evaluation of their bioavailability, safety, tolerance, and efficacy in children.
3401Dat Knows MGF (you might as well learn something as well)
3402
3403To quickly summarize the difference in function, MGF stimulates muscle stem cells (satellite cells) to reenter the cell cycle and proliferate, whereas IGF-1 is necessary for the differentiation of newly generated muscle precursor cells into myoblasts and myofibers.
3404
3405Growth Hormone bound to its receptor in the liver activates the STAT5b signaling pathway which promotes movement of that activated signaling protein to the nucleus where it induces transcription of the IGF-1 gene. From studies in mice and humans, it is evident that GH induces expression of both the endocrine form of IGF-1, the muscle form of IGF-1 and MGF. 1 Mice deficient in GH (lit/lit mice) respond to administration of GH with an acute increase in MGF, but not IGF-1, in skeletal muscle, although IGF-1 in liver is increased. 2 However the precise mechanism by which GH has distinct effects on IGF-1 and MGF expression in muscle is not completely known.
3406
3407What is known is that in response to stretch overload and the presence of growth hormone combined gene transcription in muscle and its subsequent "blueprint" assembly" are induced to create mechano growth factor (MGF also known as IGF-1Ec in humans or IGF-1EB in mice) instead of muscle IGF-1. 3
3408
3409How does the behavior of IGF-1 and MGF differ?
3410
3411"MGF is a non-secreted form of IGF-1 that can be found in the nucleus of cells in culture or in a perinuclear location in hippocampal cells after ischemia (restriction in blood supply)".
3412
3413In other words MGF never leaves the cell it was created in. For emphasis I quote from another source:
3414
3415"...MGF... is not normally secreted."
3416
3417Geoffrey Goldspink has written "that MGF increases myoblast proliferation via a different signalling pathway" then IGF-1.
3418
3419To reiterate & expand upon this concept I quote from another source:
3420
3421"IGF-1 isoforms differ in the signaling pathways they activate. By over-expressing IGF-1Ea and MGF in muscle, it has been shown that both isoforms can activate IGF-1R and AKT phosphorylation. In addition, MGF was shown to induce phosphorylation of ERK, a property not shared with IGF-1Ea."
3422
3423So IGF-1 and MGF work through different pathways not receptors. There is only one receptor, IGF-1-receptor (also insulin, IGF-II & hybrid receptors which are not relevant to this discussion). There is no MGF receptor. The reason why it would be nonsensical to have an MGF receptor is that MGF does not leave the cell.
3424
3425This contrasts with IGF-1 which is released from the liver into circulation and which is created in muscle and translocates to the cell surface. Both events result in IGF-1 binding to the IGF-1 receptor.