Myostatin (also known as growth differentiation factor 8, abbreviated GDF8) is a protein that in humans is encoded by the MSTN gene.[6] Myostatin is a myokine that is produced and released by myocytes and acts on muscle cells to inhibit muscle growth. Myostatin is a secreted growth differentiation factor that is a member of the TGF beta protein family.
Myostatin is assembled and produced in skeletal muscle before it is released into the blood stream. Most of the data regarding the effects of myostatin comes from studies performed on mice.
Animals either lacking myostatin or treated with substances that block the activity of myostatin have significantly more muscle mass. Furthermore, individuals who have mutations in both copies of the myostatin gene (popularly, but inaccurately called the “Hercules gene”) have significantly more muscle mass and are stronger than normal. There is hope that studies into myostatin may have therapeutic application in treating muscle wasting diseases such as muscular dystrophy.gdf-8 myostatin inhibitor tb 500
Biological advantage
Many different mammalian and avian species produce myostatin, indicating that the ability to produce myostatin was positively selected for. According to some researchers, this is most likely because muscle building and maintenance are biologically expensive processes that require relatively large amounts of energy and nutrients that may not always be abundant, or that could be more useful somewhere else, such as the brain. Having excessive muscle would also negatively affect speed and stamina, as it would require more energy to move at fast speeds for longer periods of time. It could also put extra strain on the heart and compromise health and longevity.
Therapeutic potential
Further research into myostatin and the myostatin gene may lead to therapies for muscular dystrophy. The idea is to introduce substances that block myostatin. A monoclonal antibody specific to myostatin increases muscle mass in mice and monkeys.
myostatin gdf 8 peptide remains unclear as to whether long-term treatment of muscular dystrophy with myostatin inhibitors is beneficial, as the depletion of muscle stem cells could worsen the disease later on. As of 2012, no myostatin-inhibiting drugs for humans are on the market. An antibody genetically engineered to neutralize myostatin, stamulumab, which was under development by pharmaceutical company Wyeth, is no longer under development.[48] Some athletes, eager to get their hands on such drugs, turn to the internet where fake “myostatin blockers” are being sold.
Resistance exercise and creatine supplementation lead to greater decreases in myostatin levels.
Myostatin levels can be temporarily reduced using a cholesterol-conjugated siRNA gene knockdown.
Athletic use
Inhibition of myostatin leads to muscle hypertrophy. Myostatin inhibitors can improve athletic performance and therefore there is a concern these inhibitors might be abused in the field of sports. However, studies in mice suggest that myostatin inhibition does not directly increase the strength of individual muscle fibers. Myostatin inhibitors are specifically banned by the World Anti-Doping Agency (WADA). In an August 12, 2012, interview with NPR, Carlon Colker stated “when the myostatin inhibitors come along, they’ll be abused. There’s no question in my mind.”
Lifestyle effects on myostatin
Myostatin expression is decreased in physically active individuals, while obesity is linked to having a higher level myostatin as well as plasma in circulation.
