A Key to Aging with Strength
Thursday, January 27, 2005
By Liz Brown
Myostatin is a protein made by muscle cells to block muscle growth. Scientists believe it plays a role in our early life, regulating muscle growth and ensuring normal development. But in adults, its role is not so clear. The protein may, however, be partly responsible for age related muscle decline in humans, called sarcopenia. Our interest is in the older adult and the sarcopenia that accompanies aging, says Marcas Bamman, one of the authors of the study. We wanted to find out why it happens and how we can reverse or prevent it.
Weight gains
Already, research has shown that weight training is the most effective way known to combat muscle decline due to aging. However, the reason why this works is not well understood. To better understand the process, Bamman and colleagues followed separate groups of men and women divided by age through a weight training program. The groups were divided into young males aged 20 to 35, young females aged 20 to 35, older males aged 60 to 75 and older females aged 60 to 75. The researchers measured the amount of myostatin present in the participants muscle tissue before exercising and then again 24 hours following a workout. They found that weight training lowered myostatin levels and that this was most noticeable in young men. We found that we can't activate the same cell cycles with the same stimulus in older people, says Bamman.
Although it is still unclear why young men are able to down regulate myostatin much more effectively than other age groups and why older women have difficulty down-regulating the protein, the discovery may one day lead to prevention of sarcopenia. There is a tight relation to how much muscle and strength a person has and (his or her) independence, says Bamman. There are many people who stand to benefit from this research.
Exciting prospects
It is possible that blocking myostatin could not only prevent muscle deterioration and enhance strength in humans, but also treat muscle wasting diseases. In fact, pharmaceutical giant Wyeth-Ayerst is already in the early test stages for a myostatin inhibitor called MYO-029.
Se-Jin Lee, a researcher at Johns Hopkins University in Baltimore, Maryland, is especially interested in myostatin blockings potential. His team was the first to discover, in 1997, that mice without myostatin had twice the muscle mass of their normal counterparts. I am, of course, quite excited about the prospect that targeting this pathway may lead to new treatments for patients with muscle degenerative and muscle wasting conditions. But though myostatin inhibitors could help many people, concerns that competitive athletes could use the drugs for performance enhancement may slow their development. I am concerned that all of the focus on possible abuse of such technology by athletes may slow work in this area, says Lee. Although we should be careful to prevent possible abuse for inappropriate purposes, we must always keep in mind that there are people in dire need of new therapies to combat muscle loss.
To this end, Bamman and his team are continuing their weight training research. We will be exploring the effects of long term weight training on myostatin, says Bamman. Our research is going extend into the advanced elderly population and we will begin studying people over 80. I believe it is a viable pursuit to help enable the elderly, he adds.
The study by Bamman and colleagues is reported in the American Journal of Physiology Endocrinology and Metabolism
We gratefully give the thanks to Better Humans website for this article
