|Monday October 2 2000 |
Protein in Muscle Lets You Eat More, Weigh Less
NEW YORK (Reuters Health) - Imagine a diet of juicy steaks, creamy desserts and heaps of buttery snacks. While this diet may cause a host of medical problems, it may not lead to obesity, preliminary study findings reveal.
A team of researchers found that by producing a certain protein in muscle cells, they could boost metabolism and prevent weight gain in mice that were fed a high-fat diet and did not exercise. The findings may eventually lead to a way to help humans to stay thin without exercising, according to the report in the October issue of Nature Medicine.
``It may be possible either through drugs or gene therapy to turn on something like uncoupling protein that would waste energy instead of storing it in fat,'' Dr. Clay Semenkovich, the study's lead author, said in a prepared statement. ``Such treatments would promote leanness.''
``The protein decreases obesity. It also clearly prevents diabetes, one of the complications of obesity,'' explained Semenkovich. ``We would predict this to result in less heart disease in these mice, a notion that we are in the process of studying.'' He stressed that similar studies in humans are years away.
However, the findings have ``led to renewed optimism that pharmacological strategies to reduce obesity and diabetes by physiological mechanisms similar to those of exercise will be possible,'' Dr. Leslie P. Kozak of the Pennington Biomedical Research Center in Baton Rouge, Louisiana, notes in an editorial.
The research team, from Washington University Medical Center in St. Louis, Missouri, bred mice that produced uncoupling protein-1 in their muscle tissue. This protein, which is not normally produced in muscle tissue, converts calories from food into heat instead of ATP.
ATP is a form of energy used by the muscle cells during exercise. Without exercise, ATP is used to produce and store fat. Uncoupling protein-1, however, was found to speed up the metabolism of muscle cells in mice, thereby mimicking the effects of exercise.
What's more, the mice bred to produce the protein remained thin, did not develop diabetes and had low cholesterol, even when they consumed a diet high in fat. They also remained as physically fit as mice fed a healthy diet.
In comparison, normal mice who consumed a high-fat diet became obese and diabetic, and developed high cholesterol.
``We've produced mice that can eat as much as they like without suffering the consequences of obesity and diabetes,'' Semenkovich added.
SOURCE: Nature Medicine 2000;6:1092-1093, 1115-1120.