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Researchers Find Drug That Mimics Effects of Exercise

August 1, 2008 at 6:40 PM EDT
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Scientists announced this week that they've found a chemical compound that allows mice to run 44 percent longer on a treadmill -- without doing any exercise. Lead researcher Ronald Evans discusses the results and what they could mean for humans.

JUDY WOODRUFF: It sounds too good to be true, but researchers say they believe they have found drugs that mimic the effects of exercise, even for those who prefer the couch to the Stairmaster.

The work was done with mice. Scientists put sedentary mice on a treadmill and found that a drug helped the mice run for a substantially longer time than those who didn’t get the drug. A second drug boosted the athletic endurance of mice who had been exercising, as well.

Here to tell us more is the study’s lead investigator, Ronald Evans. He is a professor at the Salk Institute for Biological Studies.

Dr. Evans, thank you very much for being with us. Just the sound of it is very appealing. Tell us what you found that this pill or these pills do.

DR. RONALD EVANS, Salk Institute: Well, we found two different muscle-enhancing drugs. Both of these drugs acted very powerfully to stimulate endurance, I have to say, in mice. We now want to spur this towards people.

And they kind of address one of the holy grails in our field, which is a pill that can promote fitness or endurance, especially for those who are unable to exercise.

JUDY WOODRUFF: Now, they work differently. One, as we said, is with — works if the mouse was exercising, the other if the mouse wasn’t exercising. Can you help us understand that?

DR. RONALD EVANS: Well, that’s exactly true. One pill is for people who are in good shape, basically, and who get regular exercise. We found that that pill particularly stimulates the quality of exercise, at least in mice that are getting exercise.

It does not work at all if the mice are not exercising, so that remains a very important step, because that kind of medicine or pill could have a lot of benefit for many people, but this works particularly well with exercise.

The second pill is sort of the couch-potato experiment, where the mice get no exercise, but the ones that get the pill can get up on a treadmill and behave as if they had several weeks of exercise.

Increasing endurance

JUDY WOODRUFF: So, again, help us understand. Is it actually building up the biceps and the quads in these mice without their lifting a paw?

DR. RONALD EVANS: Well, it's building up the endurance muscles in the mice, because what we're testing them on is a long-distance run. And it's not exactly a free lunch.

What it does is power up the genome to stimulate metabolic activity in the muscle, which translates into improved muscle capacity. So it's based on a genetic approach, but the drugs work extremely well in promoting endurance, even without exercise.

JUDY WOODRUFF: Now, as you said, this was all done with mice. And what everybody wants to know is, could this mean something for humans?

DR. RONALD EVANS: Well, I think that's one of the great debates. We're hoping that this alerts the medical companies and the community that it is now time to think about the possibility of developing drugs that can promote health in people and can also be used initially by people who are unable to exercise: the frail, the elderly, convalescent homes, people in wheelchairs.

I've been written to by people with back surgery, knee surgery, they can't exercise. Yet a pill that they could take that could promote a more healthful state would be a great benefit.

JUDY WOODRUFF: Do you realistically see that down the road based on what you've done, what you've seen so far?

DR. RONALD EVANS: Well, the genetic pathways that we study in the mouse are exactly the same as in people. The drugs we are using are two drugs that are being developed for people, both are in clinical trials. One is in advanced phase 3, which means close to being submitted to FDA approval.

So this is a real deal in the sense of these are advanced drugs, not for exercise or health, but rather to treat, in one case, heart disease, in the other, cholesterol.

Risk of athletic use feared

JUDY WOODRUFF: So people who have serious illnesses -- and I noticed you had concerns, and you alluded to this -- about how athletes might think about using this.

DR. RONALD EVANS: So athletes are professional, performance-related careers, and so any kind of drug that could give them a boost is going to be a great temptation. And we know that athletes at any level are willing to experiment with performance-enhancing drugs.

And so that's one of the challenges is, who's going to get the drug first? And I do worry that athletes will try to get to this very quickly.

JUDY WOODRUFF: And you've already notified, I gather, the anti-doping organization involved with the athletic competitions.

DR. RONALD EVANS: In anticipating the almost assured use of these drugs by athletes, we've developed a test that's very sensitive and quantitative that can measure these drugs in the blood and urine of mice and people.

JUDY WOODRUFF: So, finally, Dr. Evans, for those who are sitting home, watching on their sofa, eating some peanuts or potato chips, and hoping this could be the answer, what's the message?

DR. RONALD EVANS: Well, you know, we have a zooming health-care dollar, and it's to our own peril is we ignore the reality that most people do not get sufficient exercise. And so addressing this directly and providing some medical intervention is something that I think we all need to think about seriously.

JUDY WOODRUFF: Ronald Evans with the Salk Institute, thank you very much.

DR. RONALD EVANS: Thank you, Judy.