Thursday, July 31, 2008

Exercise in a Pill

This one is fascinating. I heard this discussed on a radio programme last night (31/7):

Endurance-enhancing drugs

Scientists at Salk Institute in San Diego have created what they believe is the world's first endurance-enhancing drug.

Here is the abstract:

The benefits of endurance exercise on general health make it desirable to identify orally active agents that would mimic or potentiate the effects of exercise to treat metabolic diseases. Although certain natural compounds, such as reseveratrol, have endurance-enhancing activities, their exact metabolic targets remain elusive. We therefore tested the effect of pathway-specific drugs on endurance capacities of mice in a treadmill running test. We found that PPARβ/δ agonist and exercise training synergistically increase oxidative myofibers and running endurance in adult mice. Because training activates AMPK and PGC1α, we then tested whether the orally active AMPK agonist AICAR might be sufficient to overcome the exercise requirement. Unexpectedly, even in sedentary mice, 4 weeks of AICAR treatment alone induced metabolic genes and enhanced running endurance by 44%. These results demonstrate that AMPK-PPARδ pathway can be targeted by orally active drugs to enhance training adaptation or even to increase endurance without exercise.

and had a dig round to find more. I think you should be able to listen to the programme here, at lest for a week or so.

The press release is here:

Trying to reap the health benefits of exercise? Forget treadmills and spin classes, researchers at the Salk Institute for Biological Studies may have found a way around the sweat and pain. They identified two signaling pathways that are activated in response to exercise and converge to dramatically increase endurance.

Previous work with genetically engineered mice in the Evans lab had revealed that permanently activating a genetic switch known as PPAR delta turned mice into indefatigable marathon runners. In addition to their super-endurance, the altered mice were resistant to weight gain, even when fed a high-fat diet that caused obesity in ordinary mice. On top of their lean and mean physique, their response to insulin improved, lowering levels of circulating glucose.

Then came the ultimate couch potato experiment. The researchers fed untrained mice AICAR, a synthetic AMP analog that directly activates AMPK. After only four weeks and without any prior training, these mice got up and ran 44 percent longer than untreated, untrained mice. "That's as much improvement as we get with regular exercise," says Narkar.


NHS Choices note:

Although these drugs improved endurance, they may not have the other benefits of exercise, such as weight loss and reduction in risk of various diseases. In particular, the authors specifically noted that the drugs did not affect the mice’s weight. Therefore, it is premature to suggest that these drugs could be the antidote to a couch potato lifestyle.

1 comment:

donny said...

The genetically altered mice in the earlier study ate sixty percent more, but lived longer than, the unaltered strain. Wonder if the pill will have that effect, too?