I have looked into GDF-8.
Scientific Study: Mutations in myostatin (GDF8) in Double-Muscled Belgian Blue and Piedmontese Cattle
Mutations in myostatin (GDF8) in Double-Muscled Belgian Blue*and Piedmontese*Cattle -- Kambadur et al. 7 (9): 910 -- Genome Research
Potential clinical significance
Further research into myostatin and the myostatin gene may lead to therapies for muscular dystrophy.[18] The idea is to introduce substances that block myostatin. In 2002, researchers at the University of Pennsylvania showed that monoclonal antibody specific to myostatin improves the condition of mice with muscular dystrophy, presumably by blocking myostatin's action.
In 2005, Lee showed that a two-week treatment of normal mice with soluble activin type IIB receptor, a molecule that is normally attached to cells and binds to myostatin, leads to a significantly increased muscle mass (up to 60%).[19] It is thought that binding of myostatin to the soluble activin receptor prevents it from interacting with the cell-bound receptors.
It remains unclear whether long term treatment of muscular dystropy with myostatin inhibitors is beneficial: the depletion of muscle stem cells could worsen the disease later on.
As of 2005, no myostatin inhibiting drugs for humans are on the market, but an antibody genetically engineered to neutralize myostatin was developed by New Jersey pharmaceutical company Wyeth.[20] The inhibitor is called MYO-029 and recently underwent testing however the results have not yet been made public.[21][22][23] Some athletes, eager to get their hands on such drugs, turn to the internet, where fake "myostatin blockers" are being sold.
Johns Hopkins University has developed a technique for detecting mutations in myostatin variants. [24]
source: Myostatin - Wikipedia, the free encyclopedia
Basics:
"Myostatin (formerly known as Growth differentiation factor 8) is a growth factor that limits muscle tissue growth, i.e. higher concentrations of myostatin in the body may cause the individual to have less developed muscles. The myostatin protein is produced primarily in skeletal muscle cells, circulates in the blood and lymph and acts on muscle tissue, apparently by slowing down the development of muscle stem cells. The precise mechanism remains unknown. Its functions in non-mammalian vertebrates appear to be somewhat conserved as muscle-specific actions have been demonstrated in birds. However, it is produced in many different fish tissues, suggesting that it may regulate more than just muscle mass in these vertebrates."
source: wikipedia.com
I remember watching a Youtube video (and seeing it on Discovery channel I think) of these "Belgian Blues" ...massive bulls that are bred somehow to minimze myostatin. Have you guys seen that? Holy CRAP, they are solid mountains of ripped muscle. I mean, these things have bulges hanging off of them...truly fricking insane!
