Muscle loss finding may one day save physiques

February 12, 2010

Hey guys, remember the muscle shirts we wore in our teens and 20s? After the age of 40 that meager part of our wardrobes usually is obsolete. Yes, at the big 4-0 we begin to lose muscle, and by age 80 up to a third of it may be gone. It's an inevitable process of aging called sarcopenia.

Why does sarcopenia happen and can it be stopped? A study conducted in mice with accelerated muscle loss at The University of Texas Health Science Center at San Antonio provides this insight: Less protection from antioxidants and more damage from oxidative stress results in impairment to cells' energy centers, which slowly leads to death of .

A team directed by Holly Van Remmen, Ph.D., associate professor with the university's Barshop Institute for Longevity and Aging Studies and the Department of Cellular and Structural Biology, found that without a certain antioxidant enzyme to balance the formation of harmful (ROS), cellular energy centers called mitochondria fail to work properly. The mitochondria even add to the spate of ROS molecules and release factors leading to cell death.

"The impaired function of mitochondria also has a detrimental effect on the way motor neurons 'talk' to the muscle to achieve muscle contraction," Dr. Van Remmen said. "This interaction occurs at a specialized synapse where the nerve and muscle come in close contact." This key structure is called the neuromuscular junction, she said.

Smaller and weaker muscles

Youngmok C. Jang, Ph.D., a leading author in the study, investigated mice that were genetically engineered to lack an antioxidant enzyme called copper-zinc superoxide dismutase. He compared mitochondria from these mice and normal mice and found reduced function of the energy centers in the enzyme-deficient mice. This contributed to more cell death and in the rodents. "As a result, their muscles were a lot smaller and weaker," Dr. Van Remmen said.

Insights gleaned about can help scientists better understand other neuromuscular diseases such as amyotrophic lateral sclerosis (Lou Gehrig's disease). "Age-related muscle atrophy is a complex process and involves multiple systems," Dr. Van Remmen said. "There are, however, common mechanisms occurring in sarcopenia and other neuromuscular diseases. By understanding the mechanisms underlying age-related muscle atrophy and alterations at the neuromuscular junction, we should be able to gain insight that will help us to discover new therapeutic interventions."

If a muscle-preserving therapy is one day developed, future generations of young men will be able to keep their muscle shirts a bit longer.

More information: This paper was published online by The FASEB Journal on Dec. 29, 2009.

Related Stories

Recommended for you

Engineered protein treatment found to reduce obesity in mice, rats and primates

October 19, 2017
(Medical Xpress)—A team of researchers with pharmaceutical company Amgen Inc. report that an engineered version of a protein naturally found in the body caused test mice, rats and cynomolgus monkeys to lose weight. In their ...

New procedure enables cultivation of human brain sections in the petri dish

October 19, 2017
Researchers at the University of Tübingen have become the first to keep human brain tissue alive outside the body for several weeks. The researchers, headed by Dr. Niklas Schwarz, Dr. Henner Koch and Dr. Thomas Wuttke at ...

Cancer drug found to offer promising results in treating sepsis in test mice

October 19, 2017
(Medical Xpress)—A combined team of researchers from China and the U.S. has found that a drug commonly used to treat lung cancer in humans offers a degree of protection against sepsis in test mice. In their paper published ...

Study reveals key molecular link in major cell growth pathway

October 19, 2017
A team of scientists led by Whitehead Institute has uncovered a surprising molecular link that connects how cells regulate growth with how they sense and make available the nutrients required for growth. Their work, which ...

Tracing cell death pathway points to drug targets for brain damage, kidney injury, asthma

October 19, 2017
University of Pittsburgh scientists are unlocking the complexities of a recently discovered cell death process that plays a key role in health and disease, and new findings link their discovery to asthma, kidney injury and ...

Inflammation trains the skin to heal faster

October 18, 2017
Scars may fade, but the skin remembers. New research from The Rockefeller University reveals that wounds or other harmful, inflammation-provoking experiences impart long-lasting memories to stem cells residing in the skin, ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

dirk_bruere
not rated yet Feb 14, 2010
I'm 56 and stronger than when I was 26 - still plenty of muscle for my daily 50 pushups.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.