Myostatin - any future potential?

[Dr.Dave1]

For some reason I was hit with the urge to look for some articles on myostatin this afternoon. While I realize the chance that anything found with regards to this research has very little chance of making it to the supp industry I thought it was interesting and worth sharing. So, here are some of the articles that I found relating to humans (all that mice research is interesting but does not necessarily translate into human findings).



Below is another article which I did not have access to the full text version. so it's just an abstract.


Authors Willoughby DS.
Authors Full Name Willoughby, Darryn S.
Institution Exercise and Biochemical Nutrition Laboratory, Dept of Health, Human Performance, and Recreation, Baylor University, Waco, TX 76798-7313, USA.
Title Effects of an alleged myostatin-binding supplement and heavy resistance training on serum myostatin, muscle strength and mass, and body composition.
Source International Journal of Sport Nutrition & Exercise Metabolism. 14(4):461-72, 2004 Aug.
Abbreviated Source Int J Sport Nutr Exerc Metab. 14(4):461-72, 2004 Aug.

Abstract This study examined 12 wk of resistance training and cystoseira canariensis supplementation on serum levels of myostatin and follistatin-like related gene (FLRG) and muscle strength and body composition. Twenty-two untrained males were randomly assigned to a placebo (PLC) or myostatin binder (MYO) group in a double-blind fashion. Blood was obtained before and after 6 and 12 wk of training. PLC and MYO trained thrice weekly using 3 sets of 6 to 8 repetitions at 85 % to 90 % 1 repetition maximum. MYO ingested 1200 mg/d of cystoseira canariensis. Data were analyzed with 2-way ANOVA. After training, total body mass, fat-free mass, muscle strength, thigh volume/mass, and serum myostatin and FLRG increased for both groups (P < 0.05); however, there were no differences between groups (P > 0.05). Twelve wk of heavy resistance training and 1200 mg/d of cystoseira canariensis supplementation appears ineffective at inhibiting serum myostatin and increasing muscle strength and mass or decreasing fat mass.

[DRP7]

Hi Dr.Dave, cool post! (reps!)

Well, from very general reasoning, it is one of the most difficult things to induce real hyperplasia, especially in tissues that have reached their genetically determined limit of the number of cells.
I suppose that the body has more than one mechanism to control hyperplasia, since hyperplasia that gets out of control is cancer.
I further assume that Myostatin is one of the controlling factors, and that there are several other factors. There may even exist upstream factors that regulate myostatin, so that the inability of a drug to effectively decrease / inhibit myostatin potentially could be caused by upstream upregulation of myostatine production.

And the idiots who are producing / selling myostatine blockers should thank the Lord every day that their products didn't work. If they did, we would have thousands of people now with completely deformated muscles (similar to how greg valentino looks) or with muscle-tumors.

From my (current) perspective: Manipulating cell-division is one of the greatest scientific challenges so far and just drinking a powder will at best not work or induce tumors.

Best regards

David

[Dr.Dave1]

Hey Dr.P
Thanks for the input and the kind words You have brought up some great points. It is probably a good idea to avoid rhabdomyomas if at all possible Regulation of muscle growth is a very complex topic and we definitely do not understand the consequences of tinkering with that mechanism at this point. I know there are currently some clinical trials testing myostatin blockers in degenerative muscle diseases but I have not heard of any results as of yet. My assumption is that once they determine a way to block myostatin (assuming they do at some point) there will definitely be abuse of the agents. I guess Arnold's famous line "It's not a tumor" may not necessarily hold true in the future

[Dr.Dave1]

Since I did not do it yesterday I thought I should give a quick summary of what myostatin is/does for those unfamiliar with it and then the abstracts to the articles.
Myostatin (a.k.a. GDF-8) ia a member of the TGF-beta family and is specific to skeletal muscles (not found in smooth or cardiac muscles). It is secreted in the inactive (propeptide) form and circulates in the blood. At some point the protein is activated via an as yet unknown mechanism. In vitro studies have pointed to tissue specific (skeletal muscle) metalloproteinases (just an enzyme that cleaves proteins) in the activation but in vivo mechs have not yet been demonstrated. In circulation it has been found to be bound by FLRG and GASP-1; which inhibit its action (Two possible mechs for future control of myostatin activity). Post activation myostatin can then bind to specific receptors on skeletal muscle and activate a signaling cascade which activates factors to regulate transcription of the myostatin target genes. It helps to regulate differentiation, proliferation, and fiber size.

Below are the abstracts from the articles I included
MYOSTATIN REVIEW
Myostatin, or GDF-8 (growth and differentiation factor-8), was first identified through sequence identity with members of the BMP (bone morphogenetic protein)/TGF-β (transforming growth factor-β) superfamily. The skeletal-muscle-specific expression pattern of myostatin suggested a role in muscle development. Mice with a targeted deletion of the myostatin gene exhibit a hypermuscular phenotype. In addition, inactivating mutations in the myostatin gene have been identified in ‘double muscled’ cattle breeds, such as the Belgian Blue and Piedmontese, as well as in a hypermuscular child. These findings define myostatin as a negative regulator of skeletal-muscle developmentt. Myostatin binds with high affinity to the receptor serine threonine kinase ActRIIB (activin type IIB receptor), which initiates signalling through a smad2/3-dependent pathway. In an effort to validate myostatin as a therapeutic target in a post-embryonic setting, a neutralizing antibody was developed by screening for inhibition of myostatin binding to ActRIIB. Administration of this antimyostatin antibody to adult mice resulted in a significant increase in both muscle mass and functional strength. Importantly, similar results were obtained in a murine model of muscular dystrophy, the mdx mouse. Unlike the myostatin-deficient animals, which exhibit both muscle hypertrophy and hyperplasia, the antibody-treated mice demonstrate increased musculature through a hypertrophic mechanism. These results validate myostatin inhibition as a therapeutic approach to muscle wasting diseases such as muscular rdystrophy, sarcopenic frailty of the elderly and amylotrophic lateral sclerosis.

MYOSTATIN IN MUSCLE REGENERATION
Purpose of review
Myostatin is an endogenous, negative regulator of muscle growth. Selective inhibition of myostatin may have broad clinical utility by improving regeneration in diverse and burdensome muscle disorders. An understanding of this potential is relevant because inhibitors of myostatin have recently entered clinical trials.
Recent findings: This article reviews the structure and function of myostatin, the effect of inhibiting myostatin in models of disease, and potential therapeutic approaches to blocking myostatin pharmacologically. The possibility that a myostatin inhibitor will promote muscle regeneration in human disease, as seen in animal models, is suggested by the observation that loss of myostatin results in muscle hypertrophy in a human subject.
Summary: Multiple approaches to inhibiting myostatin are suggested by the recent elucidation of its signaling pathway. An inhibitor of myostatin may be the first drug specifically designed to enhance muscle growth and regeneration.

MYOSTATIN AND OTHER DOPING
Advances in recombinant DNA technology have created one of the most powerful weapons in the current doping arsenal: recombinant proteins [Sweeney HL. Gene doping. Sci Am 2004;291:62–9; Unal M, Ozer Unal D. Gene doping in sports. Sports Med 2004;34:357–62]. Recombinant erythropoietin (EPO) and human growth hormone (hGH) are currently being abused but are fortunately detectable either directly by employing isoelectric focusing and immunoassays or indirectly by assessing changes in selected hematopoietic parameters. The detection is technically demanding due to the extent of similarity between the recombinant proteins and their endogenous counterparts.
Another issue facing detection efforts is the speed and conditions at which blood samples are collected and analyzed in a sports setting. Recently, gene doping, which stemmed out of legitimate gene therapy trials, has emerged as the next level of doping. Erythropoietin (EPO), human growth hormone (hGH), insulin-like growth factor-1 (IGF-1), peroxisome proliferator-activated receptor-delta (PPAR δ), and myostatin inhibitor genes have been identified as primary targets for doping. Sports clinical scientists today are racing against the clock because assuring the continued integrity of sports competition depends on their ability to outpace the efforts of dopers by developing new detection strategies.

RESISTANCE LOADING EFFECT ON MYOSTATIN
Myostatin inhibits myoblast proliferation and differentiation in developing muscle. Mounting evidence suggests that myostatin also plays a limiting role in growth/repair/regeneration of differentiated adult muscle by inhibiting satellite cell activation. We tested the hypothesis that myostatin mRNA expression would decrease after resistance loading (RL) with a blunted response in older (O) females (F) who have shown minimal hypertrophy [vs. males (M)] after long-term RL. As myostatin is thought to modulate cell cycle activity, we also studied the response of gene transcripts key to stimulation (cyclin B1 and D1) and inhibition (p21cip and p27kip) of the cell cycle, along with the muscle-specific load-sensitive mitogen mechano-growth factor (MGF). Twenty young (Y; 20-35 yr, 10 YF, 10 YM) and 18 O (60-75 yr, 9 OF, 9 OM) consented to vastus lateralis biopsy before and 24 h after a bout of RL (3 sets x 8-12 repetitions to volitional fatigue of squat, leg press, knee extension). Gene expression levels were determined by relative RT-PCR with 18S as an internal standard and analyzed by age x gender x load repeated-measures ANOVA. A load effect was found for four transcripts (P < 0.005) including myostatin, cyclin D1, p27kip, and MGF as mRNA levels decreased for myostatin (-44%) and p27kip (-16%) and increased for cyclin D1 (34%) and MGF (49%). For myostatin, age x load and gender x load interactions (P < 0.05) were driven by a lack of change in OF, while marked declines were noted in YM (-56%), YF (-48%), and OM (-40%). Higher cyclin D1 levels in OF led to a main age effect (36%, O > Y) and an age x gender interaction (66%, OF > YF vs. 10%, OM > YM; P < 0.05). An age x gender x load interaction (P < 0.05) for cyclin D1 resulted from a 48% increase in OF. Post hoc testing within groups revealed a significant increase in MGF after RL in YM only (91%, P < 0.05). Higher levels of cyclin B1 in O (27%, O > Y) led to a main age effect (P < 0.05). An age x load interaction for cyclin B1 (P < 0.05) was driven by a 26% increase in Y with no change in O after RL. No age or gender differences, or load-mediated changes, were detected in levels of p21cip mRNA expression. These data clearly demonstrate that RL downregulates myostatin expression and alters genes key to cell cycle progression. However, failure to reduce myostatin expression may play a role in limiting RL-induced hypertrophy in OF.

[pu12en12g]

Nice thread Dr.Dave

[Dr.Dave1]

Nice thread Dr.Dave

Thanks PU, I appreciate it. I realize that applicability of this to BB may be limited but I thought it was an interesting topic. I'm glad to see at least a few others did as well

[resurrected]

I have really not given much thought to this subject. Without further reading and studies, I would dare say gene manipulation would be in order for this to work?
I guess I need to read up on the subject. Thanks Dave for shedding some light.

[Dr.Dave1]

I have really not given much thought to this subject. Without further reading and studies, I would dare say gene manipulation would be in order for this to work?
I guess I need to read up on the subject. Thanks Dave for shedding some light.

No prob resurrected.
Gene manipulation / genetic engineering would be an option . . . however it is a very complex option. The research on gene manipulation is still in its infancy so my assumption is the first applications will be based on trying to inhibit circulating myostatin. I have seen there are currently some clinical trials using antibodies to myostatin. It will be interesting to see how it turns out.
I question it's usefulness in disorders like muscular dystrophy, which causes it's problem due to the defective dystrophin protein. Even if you have larger or more cells they still would have the mutated protein and be less effective. However, if it could slow the progression of the disease that would be beneficial. In the end I think the most effective treatment will be gene manipulation as you mentioned.
The question becomes is there any safe application in the BB world . . . that would be legal

[nick912]

It is a very interesting thing.. If someone wants to see what lack of Myostatin will do do a image search on "belgian blue bull". They have been bred to not code myostatin. The result is a bull that is about 1000lbs of solid muscle!! They have slabs of muscle that overlap slabs of muscle.

I belong to another board that Dr. Carlon Colker has his own thread on. He states that he is developing a product with a pharm company to be a "true" myostatin inhibitor.

[resurrected]

It is a very interesting thing.. If someone wants to see what lack of Myostatin will do do a image search on "belgian blue bull". They have been bred to not code myostatin. The result is a bull that is about 1000lbs of solid muscle!! They have slabs of muscle that overlap slabs of muscle.

I belong to another board that Dr. Carlon Colker has his own thread on. He states that he is developing a product with a pharm company to be a "true" myostatin inhibitor.

It would be nice to have a true blocker but..... it would be costly and it would turn out too many freaks and become misused as did steriods. It will end up becoming federally controlled and useless for someone like you and I

[pu12en12g]

GDF-8

Description :

Myostatin is a TGF-beta family member that acts as an inhibitor of skeletal muscle growth. This muscle-specific cytokine interacts with Activin type I and type II receptors, and suppresses myoblast proliferation by arresting cell-cycle in the G1 phase. Suppression of myostatin activity facilitates muscle formation and may be useful in reducing and/or preventing adiposity and type-2 diabetes. Myostatin activity can be blocked by the Activin-binding protein Follistatin, and by the propeptide of Myostatin.

Increase GnRH + _________ = increase follistatin = unlimited muscle fiber hyperplasia (also should be potentiated / enhanced with extreme stretching).

Question for you Dr. Dave1... what do you think is the most efficient and cost-effective means of stimulating GnRH (in men) without negative feedback ??

Myostatin activity can be blocked by the Activin-binding protein Follistatin, and by the propeptide of Myostatin.

^^^^

$5,200 per milligram by the way...

[Skigazzi]

It is a very interesting thing.. If someone wants to see what lack of Myostatin will do do a image search on "belgian blue bull". They have been bred to not code myostatin. The result is a bull that is about 1000lbs of solid muscle!! They have slabs of muscle that overlap slabs of muscle.

They are usually slaughtered well before their biological death due to not being able to walk, and mutliple health issues brought on by uncontrolled systemic muscle growth....heh...sounds like some of the IFBB pros

[halodrol]

i have heard this myostatin gene needs to be changed before the animal is borned by going inside the DNA and altering it or ****..so taking that **** in, you just going to **** it out anyway

[psychojoe]

i have heard this myostatin gene needs to be changed before the animal is borned by going inside the DNA and altering it or ****..so taking that **** in, you just going to **** it out anyway

wow dude, you should be a mod at avant labs!!
___
There already seems to be a lot of misconceptions about myostatin, and this lecturer on my biochemistry course isn't doing anything to help :/
http://media.putfile.com/Myostatin

[pu12en12g]

i have heard this myostatin gene needs to be changed before the animal is borned by going inside the DNA

It's a constant negative regulator of muscle growth, so that wouldn't make sense. MYO-029 (unknown compound) is undergoing clinical trials, and there are usually "other alternatives" to pharmaceuticals.

Hypothetically (or maybe not) if we could increase follistatin even a small percentage with no negative sides, it should lead to hyperplasia. Since AAS / GH appear to result in hyperplasia, this could be related.

[pu12en12g]

Regulation of Myostatin


The subject of myostatin for so many may seem to be a silly notion or simply rubbish, but as I dig deeper into the subject and scour through all the literature I can find I become excited with the possibilities for negatively regulating myostatin. Presently, others that are researching myostatin from a laboratory setting and those associations that cater to people with muscle wasting diseases are also excited from so much promise in the research that has been done thus far.

In the research to determine and identify myostatin inhibitors, the researchers have been investigating for over a year the in vivo regulation of myostatin; in other words, to determine how myostatin is kept in a homeostatic check and balance system within the organism. For a little more information into what myostatin is, without rehashing what that has already been said, myostatin is expressed initially in the myotome compartment of developing somites and continues to be expressed in the myogenic lineage throughout development in adult animals. It is common for one to say that the research is being done with mice and similar animals and that this would not reflect accurately upon the effects in human subjects. Therefore, a consensus would be that research that would yield adequate or desirable results in humans are too far away. That is not necessarily the case with respect to myostatin. Remarkably, the human, rat, murine, porcine, turkey, and chicken myostatin sequences are identical in the biologically active C-terminal portion of the myostatin molecule following the proteolytic processing site. One other factor is to determine the efficacy of animals as a human model in research would be determining a relationship in the function of myostatin between humans and other animals being studied. Fortunately, the function of myostatin appears to be conserved across species, thus improving the efficacy and time frame from animal to human model studies.

A portion of the structure of myostatin has already been mentioned very briefly. Myostatin consists of a disulfide-linked dimer of C-terminal fragments and an N-terminal propeptide in a noncovalently held complex. It is the biologically active C-terminal myostatin dimer that is capable of binding the activin type II (primarily Act RIIB, and, to a lesser extent, Act RIIA). Thus, this binding pattern inhibits muscle growth and especially inhibits hyperplasia. Based upon research it appears that myostatin, like Transforming Growth Factor-beta (TGF-beta) may normally exist in vivo in a latent complex with the propeptide (the portion of the precursor protein upstream of the proteolytic processing site) and that upon activation, myostatin may signal by binding to activin type II receptors. It is the C-terminal dimer that is biologically active in other TGF-beta family members as well.

Thus far, experimentation with the activin-binding protein follistatin and the myostatin propeptide has yielded phenomal results to inhibit the C-terminal dimer’s activity in the regulation of muscle mass.

Most members of the TGF-beta superfamily have been shown to signal by binding serine/threonine kinase receptors followed by activation of Smad proteins. The initial event in triggering the signaling pathway is the binding of the ligand to a type II receptor. During the studies it was observed that the full length of the Act RIIA and Act RIIB receptors bound to myostatin. In vitro the dissociation constant of the myostatin from its cognate receptor is higher than it probably is in vivo. It is very possible that the binding affinity for Act RIIB in vivo is much higher than in vitro since this is known to be the case for other members of the TGF-beta superfamily, especially in the presence of appropriate type I receptors and that other molecules present in vitro are involved in presenting the ligand to the receptor.

By knocking out the Act RIIB kinase domain, researchers were able to transgenically breed a dominant-negative form of Act RIIB in mice. A construct was generated in which a truncated form of Act RIIB lacking the kinase domain was placed downstream of a skeletal muscle-specific myosin light chain promoter/enhancer. By using pronuclear injections, the researchers obtained their founder animals that were dominant-negative Act RIIB for the transgene. These animals showed increases in skeletal muscle mass up to 125% more than the control nontransgenic wild type animals. Evidence suggested that the increased muscle weight resulted from the expression of the transgene without Act RIIB for the binding of the myostatin.

Another construct was made by investigating the effect of the myostatin propeptide. As with the TGF-beta members, it is known that the C-terminal dimer is held in an inactive, latent complex with the other proteins, including their propeptides, and that these propetides can have inhibiting effects on their respective TGF-beta bioactive C-terminal dimer counterparts. Indeed this is true with myostatin, yet 50 times as much propeptide is required (roughly 23.5 nM) compared to the approximate 470 pM of follistatin to obtain the inhibitory effects on the myostatin molecule.

As mentioned, follistatin was part of this research as well. Since follistatin was part of the study, follistatin yielded the most phenomenal results. Follistatin has been known to be capable of binding and inhibiting the activity of several TGF-beta family members, and, of interest, follistatin can block the activity of GDF-11, which is highly related to myostatin. From the research conducted with follistatin, it appears that follistatin is a normal in vivo regulator preventing overactivity of myostatin as part of the body’s checks and balances system for homeostasis. The muscle weights in the follistatin constructs were increased by 194% - 327% relative to the control animals. There was a 66% increase in muscle fibers (hyperplasia) and a 28% increase in fiber diameter (hypertrophy).

Concerning the truncated form of the Act RIIB as previously discussed, one possibility that makes excess muscle growth occur may not be that the truncated receptor is blocking the signaling in the target cell but is acting as a sink to deplete extracellular concentrations of myostatin. One other possibility is that the truncated receptor is blocking signaling of other ligands besides myostatin. To my knowledge as of yet, it is not known definitively that follistatin is blocking myostatin activity in vivo to promote muscle growth. With the extraordinary degree of muscling in one of the founder animals compared to the rest of the follistatin construct founders, it is probable that other follistatin sensitive ligands may be involved in regulating muscle growth. One obvious candidate would be GDF-11, which is so closely related to myostatin, and GDF-11 is also expressed in skeletal muscle tissue. Other candidate ligands would include the activins, which has been shown to be capable of inhibiting muscle cell differentiation in vitro.

Thus far, the data that has been uncovered suggest that myostatin antagonists, such as follistatin and the myostatin propeptide, or activin type II receptor antagonists may be highly effective muscle enhancing agents for human applications. Of course, additional experiments will be required and are being done successfully at present to unfold a deeper understanding of blocking myostatin’s inhibitory effects on muscle growth and identification of other signaling components as well as designer-antibody antagonists.

FYI

[pu12en12g]

Phenylephrine and glucagon also increased follistatin mRNA levels but the effects were transient and weaker than those caused by activin A.

Phenylephrine is a drug, but Synephrine is also a alpha adrenergic agonist.... the plot thickens.

This is interesting:

DHEA administration can modify neuronal GnRH gene expression in adult rats of both sexes, the effect being inhibitory in the male and stimulating in the female. This modulation of GnRH neuronal activity, which is probably exerted following the conversion of DHEA into active sex steroids, might be at least partly responsible for modifications of the activity of the hypothalamo-pituitary-gonadal axis induced by DHEA.

Follistatin (FS)1 has gained recognition as an important mediator of cell secretion, development, and differentiation in a number of tissue and organ systems. Follistatin was first isolated from ovarian follicular fluid as a protein factor capable of suppressing FSH secretion by pituitary cells in culture in a manner similar to inhibin (reviewed in Refs. 1-4). Cloning and sequencing (5) showed it to be a protein of 288 amino acids (FS-288), unrelated to inhibin, with a C-terminal-extended form (FS-315) derived from alternative splicing. No "receptor" for follistatin has been found, but its mode of action in the pituitary became clear with the demonstration (6) that the protein binds the activin A homodimer with high affinity, approaching irreversibility because of its slow dissociation rate (7).

Multiple lines of evidence have now shown that, rather than "presenting" activin to its receptor as in the case of certain circulating binding proteins, follistatin sequesters activin to prevent stimulation of FSH secretion (8, 9). More recently, follistatin has been reported to accelerate endocytosis and degradation of activin (10). Insights into follistatin's importance have paralleled the steadily unfolding evidence for multiple roles played by activin and its relatives in the transforming growth factor-beta family of regulatory factors (2, 3).

In males:

FSH also stimulates Sertoli cells to produce inhibin, which provides negative feedback to the anterior pituitary to decrease FSH secretion

6-OXO + _______ ???

6-OXO works at the level of the brain to stimulate the production of FSH and LH

FSH release at the pituitary gland is controlled by pulses of gonadotropin-releasing hormone (GnRH). Those pulses, in turn, are subject to the estrogen feed-back from the gonads.

[GM54]

http://msnbc.msn.com/id/5278028/

[nick912]

great article guys! My friend Dr. Carlon Colker is working on a true myostatin inhibitor. Here is a quote from his forum on another board. "There IS a real orally ingested non-prescription myostatin inhibitor coming out of a biopharma company from texas called Celldyne. i know the preliminary research in press and it's astounding. It's called Folstaxan and they have actually verified the decrease in serum myostatin the male human after dosing! If they can just get the product out there it will revolutionize the industry and we will certainly see a 400lbs. ripped mr. olympia, no kidding."

I have been on his case on a ETA for this and it is still unknown.

[pu12en12g]

http://msnbc.msn.com/id/5278028/

If you liked that one, you will love this one:

October 1, 1998

Re: Flex Wheeler

To whom it may concern:

I am writing this letter per the request of Flex Wheeler.

I would first like to briefly provide you with some background information regarding BALCO Laboratories. BALCO has been working with elite Olympic and professional athletes for over fifteen years. BALCO has provided testing and consultation for over 250 NFL players including the entire 1998 Super Bowl Champion Denver Broncos team and the entire Miami Dolphins team. BALCO works with professional athletes in many sports including teenis (Michael Chang, Jim Courier, etc.), hockey, bodybuilding (10 of the 16 1998 Mr. Olympia contestants), track and field, soccer and basketball (Seattle SuperSonics).

BALCO Laboratories has been testing and monitoring Flex on a routine basis during the last year. We have performed tests including blood chemistry (SMAC), complete blood count (CBC), PSA, anabolic hormone levels, genotyping as well as comprehensive testing for nutritional elements. Flex's test results have been compared to twenty-four other professional bodybuilders and overall he has one of the healthiest profiles. Basically, Flex is in excellent health and has demonstrated the discipline necessary to maintain a peak level of conditioning.

Flex was a participant in a study we recently conducted in collaboration with the Department of Human Genetics at the University of Pittsburgh involving 62 men who made unusually large gains in muscle mass in response to strength training (extreme responders). Flex was one of only nine extreme responders that had the very rare "myostatin mutation." Myostatin is the gene that "limits muscle growth." Specifically, Flex had the rarest form of myostatin mutation at the "exon 2" position on the gene. This simply means Flex has a much larger number of muscle fibers compared to the other subjects or the normal population. We believe that these are the very first myostatin mutation findings in humans and the results of this landmark study have already been submitted for publication. Flex was also found to have a very unusual type of the IGF-1 gene. In fact, Flex was the only participant in the study that did not have a "match." All of the other extreme responders had at least three other subjects with a matching IGF-1 gene. Based upon Flex's very unique genetic profile, we plan to expeditiously publish a scientific paper that reveals his complete genotype in specific detail. The publication of his remarkable genetic data should generate an enormous amount of media exposure.

Hope this information will be helpful and please call if I can be of assistance.

Sincerely,

/s/ Victor Conte
Victor Conte
President
BALCO Laboratories, Inc.

1520 Gilbreth Road • Burlingame, CA 94010 • 1-800-777-7122 • FAX (650) 687-6576

[halodrol]

wow is this **** abt flex for real? i feel like i am watching xmen 4 or something

[halodrol]

http://msnbc.msn.com/id/5278028/

kid's got nice outer sweep

if he lives, he would beat ronnie lol

[pu12en12g]

wow is this **** abt flex for real? i feel like i am watching xmen 4 or something

The study itself appears to be legit:

MATERIALS AND METHODS

Sequencing of selected regions of the myostatin gene and genotyping
of common variants were carried out in a comparison sample of
96 randomly selected Caucasian and 96 African American subjects
from the general population. An additional 72 individuals were
screened for a common exon 2 variant. One hundred fifty-three
subjects, including 127 men (32 African American, 91 Caucasian,
and 4 Asian) and 26 women (9 African American, 16 Caucasian, and
1 Asian), were categorized by the magnitude of increases in muscle
mass they experienced from strength training. The subjects consisted
of world-class bodybuilders (ranked in the top 100 worldwide)
(N 5 18; 5 were ranked in the top 10), competitive bodybuilders not
ranked in the top 100 (N 5 25), elite power lifters (N 5 7), university
football players (N 5 9), previously untrained subjects who had their
quadricep muscle volume measured by magnetic resonance imaging
before and after 9 weeks of heavy resistance strength training of the
knee extensors (N 5 33), and nonathletes, who were questioned
about their ability to increase their muscle mass in response to
intense and prolonged strength training (N 5 61). A rating of 5 was
given to those who were world-class bodybuilders and to those who
increased their quadriceps muscle mass by .400 cm3 after only 9
weeks of strength training, whereas a rating of 0 was given to those
who experienced no noticeable increase in muscle mass after vigorous
strength training for at least 6 months. Eighteen subjects received
a rating of 5, and 13 subjects received a rating of 0. The
ratings of the remaining subjects fell somewhere between these two
extremes. Subjects who were rated as either 4 or 5 were classified as
extreme responders (N 5 62) and were compared to those who were
rated as either 0 or 1 and were classified as nonresponders (N 5 48).
Subjects were also grouped and compared by race. Information on
muscle mass changes with strength training from the remaining
subjects was obtained through either estimates of fat-free mass
assessed by dual-energy X-ray absorptiometry or hydrodensitometry
or in the case of competitive bodybuilders, power lifters, football
players, and nonathletes, through questionnaire data on prior success
in bodybuilding competition and/or reported changes in muscle
mass with strength training. Informed consent was obtained from all
subjects under protocols approved by the Institutional Review
Boards of the University of Maryland and the University of Pittsburgh.
Laboratory methods. Genomic DNA was prepared from EDTA
anticoagulated whole blood or from cheek swabs by standard methods
(Miller et al., 1988). DNA amplification primers for each exon and
the 59-flanking region of the human myostatin gene were designed
based on the cDNA sequence of human myostatin (GenBank Accession
No. AF019627) and the genomic organization of the bovine
myostatin gene (Grobet et al., 1997).

it is interesting to note that three of the
African American nonresponders were homozygous for
the less common (Arg) allele at the exon 2 K153R site,
while none of the responders were homozygous for this
allele. Three of the five mutations causing the doublemuscle
phenotype in cattle occur in exon 2 and are
recessive, but two are chain termination mutations
and one is a deletion, expected to produce a nonfunctional
myostatin protein (Grobet et al., 1998). Whether
variation in the myostatin gene influences muscle phenotypes
other than the muscle mass increase in response
to strength training requires further exploration.

Looks like it's legit....

[reflexions]

I found this thread.
http://forum.bodybuilding.com/showthread.php?t=26974

Also if you are going to make claims like this;

http://www.bodybuilding.com/store/cyt/myoblast.html

No one is going to take you seriously.

Sorry if a re post.

[Dr.Dave1]

Question for you Dr. Dave1... what do you think is the most efficient and cost-effective means of stimulating GnRH (in men) without negative feedback ??

There is a problem with stimulating release of GnRH in that if it is released constantly you end up with chemical castration. So, you want to avoid long acting agonists. The key is to mimic the pulsatile release that occurs naturally. You can increase GnRH w/ drugs but I assume you are more interested in nonprescription means of this

a quick little article; a bit dated but the basics still hold for the most part

Mechanisms of Stress on Reproduction: Evidence for a Complex Intra-Hypothalamic Circuit
CALOGERO, ALDO E et al
Annals of the New York Academy of Sciences. 851:364-70, 1998 Jun 30.
CORTICOTROPIN-RELEASING HORMONE
The suppressive effect of chronic stress on the HPG axis is believed to be due primarily to the influence of the elevated levels of endogenous CRH. Indeed, the injection of CRH into the grey mesencephalic area inhibits sexual receptivity in the female rat, 6 and its injection into the cerebral ventricles reduces plasma LH levels in adrenalectomized/ovariectomized rats. 7 Because CRH does not influence the release of gonadotropins and of PRL from the pituitary gland, 8,9 these observations suggest that CRH inhibits the HPG axis by acting at the hypothalamic level. Accordingly, CRH is capable of suppressing hypothalamic GnRH release in vitro and in vivo. 10,11 Corroborating a physiological role of the increased intrahypothalamic CRH endogenous tone during stress is the finding that the central administration of a CRH receptor antagonist to stressed rats restores plasma LH levels. 12 However, there is also evidence for a stress (footshock)-induced suppression of the HPG axis not modulated by CRH. 13

Although a direct synaptic connections between CRH-secreting and GnRH-containing neurons has been shown in the rat, 14 [b]CRH-induced suppression of GnRH release appears to be mediated by an increased tone of EOP both in vivo and in vitro.[b] 11,15 In fact, CRH is a regulator of the synthesis, processing, and release of POMC-derived peptides not only at the pituitary level, but also in the hypothalamus and particularly of [beta]-endorphin ([beta] -EP). 16 Because the arcuate nucleus is the main site of POMC-derived peptides within the hypothalamus, 17 it can be postulated that CRH acts on this nucleus to increase the production of hypothalamic EOP.

ENDOGENOUS OPIOID PEPTIDES
A large body of literature has indicated that EOPs exert a tonic inhibitory role in the regulation of gonadotropin secretion. 18 This tonic inhibition is demonstrated by the ability of the nonselective opioid receptor antagonist naloxone (opiode antagonist) to elicit a rise in LH plasma levels and an increase in the frequency and amplitude of LH pulsatile release. 19 Conversely, the administration of [beta]-EP is able to suppress plasma LH levels in humans. 20

Although a direct effect of [beta]-EP on the pituitary gland cannot be entirely ruled out, 21 the majority of the data suggest that EOPs suppress gonadotropin release by inhibiting hypothalamic GnRH release. 22 This hypothesis is also supported by the finding that morphine, an opiate receptor agonist, blunts the peak of GnRH in the hypophyseal portal blood circulation during proestrus in the rat 23 and suppresses the electrical activity of the hypothalamic structures involved in the regulation of GnRH release. 24 This conclusion is further strengthened by the existence of direct synaptic contacts between [beta]-EP-containing fibers originating from the arcuate nucleus and GnRH-releasing neurons in the medial preoptic area. 25

CATECHOLAMINES
The role of norepinephrine on GnRH/gonadotropin release has been a matter of debate, since both stimulatory and inhibitory effects have been reported. A recent study showed that the direct application of norepinephrine onto the PVN decreases plasma LH level in the rat and that this effect is antagonized by [alpha]-adrenergic receptor antagonists. 26 An [alpha]-adrenergic mechanism also mediates the stimulatory effects of norepinephrine on CRH release, 27 suggesting the possible involvement of this neuropeptide on norepinephrine-induced suppression of the HPG axis. 26 However, norepinephrine may also act directly on the preoptic area to inhibit GnRH release. 28

Dopamine is another catecholamine that is released during stress. 29 Although there is not strong evidence for a direct effect on reproduction, [b]dopamine may participate in the regulation of the HPG axis by inhibiting the release of PRL, a pituitary and hypothalamic hormone capable of suppressing the reproductive function[b] (see next paragraph). On the other hand, PRL is able to increase the turnover of hypothalamic dopamine through a positive feedback mechanism. 30 A profound increase of the dopaminergic tone may also stimulate CRH release, and this increases the release of EOPs, 31 which, as mentioned above, are able to suppress GnRH release. 18

PROLACTIN
Although PRL acts at all levels of the HPG axis, the most relevant effect is on the hypothalamic-pituitary unit, since the hypogonadism observed during hyperprolactinemia is characterized by low levels of gonadotropins. Experimental studies have shown that the inoculation of a pure PRL-secreting tumor or the implantation of pituitary glands under the kidney capsule in the rat reduces plasma LH levels by suppressing hypothalamic GnRH release. 32,33 Accordingly, we have shown that PRL is able to suppress the release of GnRH from hypothalami incubated in vitro. 34

The effect of PRL on GnRH is not direct, but appears to be mediated by EOP, CRH, and/or catecholamines. Indeed, the antagonism of opioid receptors overcomes the hypogonadotropic hypogonadism observed during hyperprolactinemia, 32,35 and accordingly PRL stimulates the release of hypothalamic [beta]-EP in vitro. 36 A number of observations suggests that CRH may also be involved because hyperprolactinemia is often associated with a hyperactive HPA axis, 37 and PRL stimulates the release of hypothalamic CRH. 38 In addition, PRL has been reported to be capable of stimulating the release of norepinephrine from the hypothalamus 39; and decreased dopaminergic tone (depletion, receptor antagonism, etc.), resulting in an increased release of PRL, may amplify the stress-induced inhibition of GnRH release mediated by PRL.

GLUCOCORTICOIDS
Increased endogenous production (i.e., Cushing syndrome) or pharmacological intake of GCs suppresses the sexual/reproductive function, which returns to normal when the excess is corrected. 40 This suppression is caused by the inhibition of gonadotropin release. 41 Because GCs have only scanty direct effects on pituitary gonadotropin release, 42 their main site of action is the hypothalamus where they are capable of inhibiting GnRH release. 43 Also in humans there is evidence suggesting an inhibitory effect of GCs on GnRH release, since dexamethasone, a synthetic GC, suppresses post-castration gonadotropin levels 44 and has practically no effect on gonadotropin release stimulated by exogenously injected GnRH. 45

INTRAHYPOTHALAMIC NEUROENDOCRINE CIRCUIT
This experimental evidence suggests the presence of a complex intrahypothalamic neuroendocrine circuit that may mediate the suppressive effects of stress on GnRH release. Stress causes an increase of (a) HPA axis function, driven by the increased release of CRH; (b) the activity of the norepinephrinergic and dopaminergic systems; and (c) PRL release, which increases dopamine turnover. Each of these factors suppresses the release of GnRH, and the effects of CRH and PRL are mediated by EOPs. 11,15,32,35 This common inhibitory pathway and the observation that PRL stimulates hypothalamic CRH release 38 suggest that PRL may act on GnRH through a CRH-dependent mechanism. Indeed, the inhibitory effect of PRL on hypothalamic GnRH release was overcome not only by an antagonist of opioid receptors, but also by a CRH receptor antagonist in vitro. 36 Because PRL also stimulates the release of norepinephrine 39 and this neurotransmitter stimulates hypothalamic CRH release, 27 it could be hypothesized that norepinephrine may be a component of the intrahypothalamic circuit responsible of the stress-induced suppression of GnRH release. We tested this hypothesis and found that [alpha]-adrenergic (but not [beta]-adrenergic) receptor antagonists overwhelmed the suppressive effects of PRL on GnRH release and its stimulatory effect on CRH release in vitro. 46 Hence, based on these premises, the following intrahypothalamic neuroendocrine circuit may be proposed: PRL activates the hypothalamic CRH-secreting neurons through an [alpha]-adrenergic mechanism. CRH, in turn, increases intrahypothalamic [beta]-EP levels, which is ultimately responsible for the inhibition of GnRH release. Dopamine may also be involved in this circuit being able to suppress the release of PRL and to modulate EOP tone through CRH (Fig. 1). In addition, many other factors may modulate the activity of this complex intrahypothalamic circuit and among these a relevant role, during stressful conditions, is certainly played by GCs, which have a great impact on each component of the circuit.
In conclusion, stress negatively modulates the HPG axis inhibiting GnRH release by increasing the hypothalamic EOP tone, regardless of whether this is triggered by elevation of intrahypothalamic CRH, catecholamine, and/or PRL levels.

Their hypotheses were somewhat convoluted & that still seems to be the case today, lots of theories but no sure answers. However, I have no specific background in endocrinology, if someone else does please chime in.

[Dr.Dave1]

great article guys! My friend Dr. Carlon Colker is working on a true myostatin inhibitor. Here is a quote from his forum on another board. "There IS a real orally ingested non-prescription myostatin inhibitor coming out of a biopharma company from texas called Celldyne. i know the preliminary research in press and it's astounding. It's called Folstaxan and they have actually verified the decrease in serum myostatin the male human after dosing! If they can just get the product out there it will revolutionize the industry and we will certainly see a 400lbs. ripped mr. olympia, no kidding."

I have been on his case on a ETA for this and it is still unknown.

I'm a bit skeptical based on similar claims made by other companies previously. However, I will be interested to see what they actually have and if they have any research to back it up.

[pu12en12g]

Awesome posts dave... actually talked to my doc today about it (among other things), and he agreed that to "mess with" this stuff and KNOW in advance you are messing with it is much different from taking "prohormone XYZ" and "hoping for the best" like most guys are doing.

We discussed the bodies amazing abiluity to "recover" and I showed him most of this stuff. He said he will do monthly bloodwork for me at no charge if we figure something out, and to say that he is "very interested" in the hyperplasia aspect is the understatement of the year.

Related read for those subscribed to this thread:
http://www.berkeley.edu/news/media/r...toninfin.shtml

[Dr.Dave1]

Awesome posts dave... actually talked to my doc today about it (among other things), and he agreed that to "mess with" this stuff and KNOW in advance you are messing with it is much different from taking "prohormone XYZ" and "hoping for the best" like most guys are doing.

We discussed the bodies amazing abiluity to "recover" and I showed him most of this stuff. He said he will do monthly bloodwork for me at no charge if we figure something out, and to say that he is "very interested" in the hyperplasia aspect is the understatement of the year.

Related read for those subscribed to this thread:
http://www.berkeley.edu/news/media/r...toninfin.shtml

Wow can't beat free stuff. See if he'll provide some experimental meds too . . . j/k It sounds like you have a good doc It's nice that he is taking such an interest in helping you out on this one.

[pu12en12g]

Ok, this isn't supposed to be mind-blowing... but somatostatin = myostatin AFAIK ?

Since clonidine acts by releasing endogenous GHRH, similar studies were undertaken employing arginine, which presumably enhances GH release by reducing somatostatin discharge. Arginine administration in obese subjects induced an increase in GH levels of 5 +/- 2.3 micrograms/L, which was significantly smaller than that in the matched control subjects (13.3 +/- 2.4 micrograms/L). Pretreatment with pyridostigmine increased the arginine action toward a GH peak of 12.2 +/- 2.2 micrograms/L in the obese and 21.6 +/- 2.5 micrograms/L in control subjects. As a third hypothalamic stimulus of GH secretion, trials of insulin-induced hypoglycemia were carried out. Hypoglycemia induced an increase in GH levels in obese subjects of 12.2 +/- 1.8 micrograms/L, which was higher than that produced by any other stimulus, but lower than that in control subjects (28.4 +/- 5.5 micrograms/L). In contrast with the previous two GH stimuli, pretreatment with pyridostigmine did not modify the hypoglycemia-induced GH release in either obese or normal subjects. Our results lend support to the view that clonidine acts through GH-releasing hormone release and arginine by reducing somatostatin discharge from the hypothalamus.

[pu12en12g]

Expanding on that last post:

I try to keep a pretty open mind. A myostatin inhibitor is kind of like the bodybuilding "holy grail"... and I always give credit to Chuck for producing one of the very FIRST Nitric Oxide products that:

1) Was time release
2) Included potent antioxidants

It's no secret that Chuck's ENP product forever changed the way I viewed "supplements".... back on topic... where the hell am I going with the whole myostatin thing right ?

"NO stimulates myoblast fusion via cGMP signaling and follistatin. Increasing NO in vivo stimulates muscle fiber formation, which suggests a potential therapeutic approach for muscular dystrophy."

NO induces myoblast fusion
Rabiya S. Tuma
J. Cell Biol. 2006 172: 165.

Also see:

Follistatin induction by nitric oxide through cyclic GMP: a tightly regulated signaling pathway that controls myoblast fusion

J. Cell Biol. 2006 172: 233-244.

Addolorata Pisconti, Silvia Brunelli, Monica Di Padova, Clara De Palma, Daniela Deponti, Silvia Baesso, Vittorio Sartorelli, Giulio Cossu, and Emilio Clementi