Researchers Identify Gene That Enhances Muscle Performance

[Frank]

Source: Dartmouth College
>
> Date: December 27, 2006
>
>
> Science Daily — A team of researchers, led by scientists at
Dartmouth Medical School and
> Dartmouth College, have identified and tested a gene that
dramatically alters both muscle
> metabolism and performance. The researchers say that this finding
could someday lead to
> treatment for muscle diseases, including helping the elderly who
suffer from muscle
> deterioration and improving muscle performance in endurance
athletes.
>
> The researchers report that the enzyme called AMP-activated protein
kinase (or AMPK) is
> directly involved in optimizing muscle activity. The team bred a
mouse that genetically
> expressed AMPK in an activated state. Like a trained athlete, this
mouse enjoyed increased
> capacity to exercise, manifested by its ability to run three times
longer than a normal
> mouse before exhaustion. One particularly striking feature of the
finding was the
> accumulation of muscle glycogen, the stored form of carbohydrates,
a condition that many
> athletes seek by "carbo-loading" before an event or game. The study
appears in the Nov.
> 14 online issue of the American Journal of Physiology:
Endocrinology and Metabolism.
>
> "Our genetically altered mouse appears to have already been an
exercise program," says
> Lee Witters, the Eugene W. Leonard 1921 Professor of Medicine and
Biochemistry at
> Dartmouth Medical School and professor of biological sciences at
Dartmouth College. "In
> other words, without a prior exercise regimen, the mouse developed
many of the muscle
> features that would only be observed after a period of exercise
training."
>
> Witters, whose lab led the study, explains that this finding has
implication for anyone with
> a muscle disease and especially for the growing proportion of the
population that is aging.
> Deteriorating muscles often make the elderly much more prone to
fall, leading to hip and
> other fractures. According to Witters, there is tremendous interest
in the geriatric field to
> find ways to improve muscle performance.
>
> "We now wonder if it's possible to achieve elements of muscular
fitness without having to
> exercise, which in turn, raises many questions about possible modes
of exercise
> performance enhancement, including the development of drugs that
could do the same
> thing as we have done genetically," he says. "This also might raise
to some the specter of
> 'gene doping,' something seriously being talked about in the future
of high-performance
> athletes."
>
> Witters says that the carbohydrate, glucose, is a major fuel that
powers muscles, and this
> contributes directly to a muscle's ability to repetitively contract
during exercise. The
> activated AMPK in the Dartmouth mouse appears to have increased
glycogen content by
> actually switching on a gene that normally synthesizes liver
glycogen.
>
> "The switching on of this liver gene in muscles," he says, "is a
shift in the conception of the
> biochemistry of muscle metabolism, since many enzyme genes are
thought to only be
> active in just one tissue."
>
> Other authors on the paper include Laura Barré, Christine
Richardson, and Steven Fiering,
> all at Dartmouth; Michael Hirshman and Laurie Goodyear of Joslin
Diabetes Center in
> Boston; Joseph Brozinick with Eli Lilly and Company; and Bruce Kemp
of the St. Vincent's
> Institute in Australia.
>
> This research is funded by the National Institutes of Health.
>
> Note: This story has been adapted from a news release issued by
Dartmouth College.
>

[molecule2005]

amazing information Frank thanks for sharing!