Date: Wed, 3 May 2000 18:45:50 -0500 From: "Jan Baggerud Larsen, Teamleder 8366" Subject: Cellular key to muscle growth found ) I got this from another list. Comments? Jan Oslo, Norway Canadian finds cellular key to muscle growth Offers potential for those in wheelchairs Brad Evenson National Post Hope has arrived for the world's 98-pound weaklings, says a Canadian researcher who has found a way to flick the cellular switch that produces muscles. "We will now have the ability to make more muscle when we want it and where we need it," said Dr. Judy Anderson, a muscle cell biologist at the University of Manitoba. Dr. Anderson says the research can also be applied to disease treatment, ageing, agriculture, sports medicine and even space travel. Until now, the only way to boost muscle growth was through disease or by injury. Weightlifting, for example, creates many micro-injuries that cause a muscle to grow as the tissue is repaired. "Muscle cells are long, cigar-shaped tubes that go between tendons," Dr. Anderson explains. When something goes wrong in a muscle cell, it sends nitric oxide to so-called satellite cells just above the muscle fibre, which sparks a muscle-growth process. "We haven't known how to turn on these satellite cells before," Dr. Anderson says. "Now that we do, we have the potential to optimize muscle repair for those who use wheelchairs or others who are not able to exercise and maintain regular movement." Nitric oxide can be released in many ways, such as stretching muscles, or through muscle and nerve damage. In some diseases, such as muscular dystrophy, this nitric oxide signal is disrupted, so that muscle tissue wastes away over time. In a study published in the journal Molecular Biology of the Cell, Dr. Anderson shows how certain compounds can stimulate the amount of nitric oxide that muscles release. "Let me tell you, we've got mice that are on these compounds that are bigger, stronger and their satellite cells are activated," she says. "After only a week, there's a major difference in what their muscles are doing. I don't know if we've got Arnold [Schwarzenegger], but we've got big changes for sure." Dr. Anderson sees the first applications of the procedure in rehabilitative medicine. "You could say, 'Well, I'm going for surgery. I need the muscle as busy as it can be as soon as that can happen. So I'm going to activate those cells now, just before surgery, and I need those repairs faster.' Or let's say you've had a stroke and you want your rehabilitation to go really well, so you could actually maintain muscle mass through this mechanism while you were allowing your nervous system to repair from this stroke." The technique also has applications for ordinary ageing. After age 30, muscle mass begins to dwindle in most adults. This causes a loss of "pull" on bones, which leads to osteoporosis, the loss of bone density. Similarly, the weightless environment of space travel is understood to decrease muscle mass, even when astronauts do plenty of exercise. "One of the things that we're going to be testing is how that will augment meat production in agriculture," says Dr. Anderson. "Nitric oxide is something that all species have, so I expect that fish, chickens and all kinds of things could be affected." While Olympic athletes and bodybuilders will no doubt be interested, Dr. Anderson says this technology can also be used to test for illegal muscle-building drug use. "There's a possibility to turn this around another way and use it as a screening tool," she says. Stimulating nitric oxide is a superior technique to steroids and other compounds, she says, because it is the body's natural muscle-growth system and it is specific. =======