A gene therapy treatment intended to reverse muscle weakness appears to restore muscle mass in monkeys, raising hopes that doctors may soon be able to treat this condition in humans with degenerative diseases like multiple sclerosis and muscular dystrophy. Scientists injected a gene into the monkeys’ thighs that causes cells to produce human follistatin, which interferes with another compound called myostatin. Myostatin breaks down muscle, so in theory adding follistatin should encourage muscles to grow [Reuters].
And grow they did. Within three months the monkeys’ thigh muscle mass increased, and the effect lasted for 15 months, according to the research published in the journal Science Translational Medicine. (Not quite the same effect as the whippet turned hugely muscular by a natural genetic defect.) The relatively long-lasting effect is promising for researchers looking to treat lifelong conditions such as multiple sclerosis and muscular dystrophy. The researchers say the treatment was safe and that no other organs were affected.
But there could be a downside to this promising work–some experts are asking whether this therapeutic technique could be used by unscrupulous athletes looking to tweak their genetics and to build stronger muscles. The drugs companies Amgen and Wyeth have already begun testing myostatin inhibitors in humans and such studies have already prompted fears about the potential for myostatin inhibitors to be abused by athletes hoping to gain the competitive edge. If gene therapy can achieve similar outcomes in humans, such modifications will be even harder to detect [New Scientist]. The World Anti-Doping Authority has banned gene doping in athletic competitions for obvious reasons, even though there’s no evidence that any athletes are tinkering with their genes.
Of course there wouldn’t be: If some jock were gene doping, there would be no way to detect it.
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Image: Wikimedia Commons / Muhammad Mahdi Karim
Unscrupulous athletes may soon find it much harder to get away with juicing. Anti-doping agencies are trying out “biological passports,” electronic records for individual athletes which provide baseline measurements of substances in their blood and urine. The record is built up over time through repeated sampling, and later tests can look for suspicious changes that may indicate the use of performance enhancing substances. As cycling has been particularly hammered by allegations of doping athletes, the International Cycling Agency has lead the charge on biological passports. Over a year, it took around 8300 blood samples from 804 cyclists. It recently revealed that a small number of these athletes’ profiles are “under further scrutiny” [New Scientist].
Doping has gone far beyond obvious substances like steroids; in recent years athletes have been caught injecting hormones for a competitive edge, and even getting transfusions of their own blood to discreetly boost their red blood cell counts. The biological passport would combat this increasingly sophisticated arsenal of tricks. Rather than ordinary spot-testing approaches, which look for unnatural ratios between biological constituents in a single sample or for direct chemical evidence of known doping agents, the passport allows investigators to see the big picture—any deviations from the rider’s test-established norm that might result from doping, even if the specific drug or tactic remains unknown [Scientific American].
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In the first major doping scandal of the Beijing Olympics, a North Korean pistol shooter has been stripped of his silver and bronze medals after testing positive for the drug propranolol. The drug, which belongs to a class called beta-blockers, would not be considered a performance-enhancing drug in most sports; it works by blocking the action of adrenaline, and therefore lowers blood pressure and heart rate.
Cardiologist Sandeep Jauhar explains that while propranolol is used to treat high blood pressure, it has additional uses: “It’s also used to treat other conditions that are mediated by high adrenaline levels, such as tremor and performance anxiety. Beta blockers don’t lower the anxiety level, but they lower manifestations of the anxiety, such as fast heart rate, sweating, and tremor” [Scientific American]. Anti-doping officials from the International Olympic Committee (IOC) believe that the shooter, Kim Jong Su, used the drug to keep his hands from shaking during the competition.
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Researchers have developed two drugs that mimic some of the effects of exercise in mice, leading to rampant speculation that people may soon be able to take a dose of “exercise in a pill.” The dramatic study showed that the drugs built fat-burning muscles in mice and increased their endurance on an exercise wheel. Four years ago researchers bred genetically engineered mice that could run much further than normal, but this is the first test to prove that drugs can have the same effect [Telegraph].
“It’s tricking the muscle into ‘believing’ it’s been exercised daily,” said the study’s lead researcher, Ronald Evans…. “It’s basically the couch potato experiment, and it proves you can have a pharmacologic equivalent to exercise” [Wired News]. One drug proved effective for mice that were already exercising regularly, increasing their running time by 68 percent and distance by 70 percent. The other drug worked on mice that hadn’t been trained to exercise; that compound increased their running time by 23 percent and distance by 44 percent.
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Despite the International Olympic Committee’s vow to vigilantly test for performance enhancing drugs at the Summer Olympics in Beijing, some scientists and sports doctors say that athletes are likely to cheat at the games, and get away with it.
The focus is on erythropoietin (EPO), a hormone naturally produced by the kidneys which regulates red blood cell production. When extra EPO is injected before a competition, it boosts performance by increasing the amount of red blood cells in an athlete’s body; those blood cells then carry more oxygen to the hard-working muscles.
Anti-doping agencies regularly test athletes for EPO, but some researchers say the agencies can’t develop tests fast enough to keep up with new “copycat” versions of EPO, often produced by pharmaceutical companies in India, Cuba, and China. These cheap versions of EPO, often called biosimilars, can be easily bought over the internet…. Some scientists who track and monitor the development of copycat EPO drugs say there could be up to 80 different versions now being manufactured in different parts of the world [BBC News].
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