THE BENEFITS OF EXERCISE: NOW IN PILL FORM
We’re all told to exercise more, but for those with physical disabilities that isn’t always possible. For such people, the benefits of aerobic exercise have always been out of reach. But now a team at the Salk Institute for Biological Studies in San Diego, California has developed a pill that engenders such effects chemically, with mice given the drug able to burn fat more effectively while exhibiting increased stamina.
When people exercise regularly, their bodies become more adept at using fat rather than glucose as an energy source. It’s been known for some time that this ability is linked to the expression of a gene called PPARD – mice that were genetically engineered to have this gene permanently activated proved more resistant to weight gain than normal mice, and had more stamina.
The new research involved giving mice a chemical compound called GW1516, which also activates the PPARD gene, over a period of eight weeks. Mice given GW1516 could typically run for 270 minutes before becoming exhausted, compared to 160 minutes for the control group. Closer examination showed that when the PPARD pathway is activated, the expression of 975 different genes within the muscles is affected, with those involved in burning fat increased and those involved in breaking down glucose suppressed.
“PPARD is suppressing all the points involved in sugar metabolism in the muscle, so glucose can be redirected to the brain,” explained researcher Dr Michael Downes. “Exercise activates PPARD, but we’re showing that you can do the same thing without mechanical training.”
The research sheds new light on the factors affecting endurance, and offers disabled patients the hope of improved quality of life.
Calf muscle of a mouse, stained to show three different types of muscle