A University of Iowa study suggests that the prolonged fatigue after mild exercise that occurs in people with many forms of muscular dystrophy is distinct from the inherent muscle weakness caused by the disease.
The research, which is published in Nature Advance Online Publication Oct. 26, identifies a faulty signaling pathway that appears to cause exercise-induced fatigue in mouse models of muscular dystrophy. Moreover, the study shows that Viagra can overcome the signaling defect and relieve the fatigue. The findings suggest that targeting the signaling pathway may lead to therapies for this type of fatigue.
"This is an exciting finding and our research suggests that there probably are many different neuromuscular conditions where fatigue could be treated by targeting this newly discovered pathway," said Kevin Campbell, Ph.D., UI professor and head of molecular physiology and biophysics and a Howard Hughes Medical Institute investigator, who holds the Roy J. Carver Chair of Physiology and Biophysics.
Using animal models, the researchers showed that if an enzyme called neuronal nitric oxide synthase (nNOS) is not present at its normal location on the muscle membrane, then blood vessels that supply active muscles do not relax normally and the animals experience post-exercise fatigue.
Early clues about the role of nNOS came from observing that the significant inactivity of dystrophic mice following mild exercise was very similar to the fatigue experience by muscular dystrophy patients after a short period of walking.
"A clinician colleague said, 'Those mice behave just like my patients with Becker muscular dystrophy.' As soon as he said that we knew what might be going on, because Becker patients have mislocalized nNOS," Campbell said.
Working with mouse models of muscular dystrophy and normal mice engineered to lack nNOS, the UI team, including lead study author Yvonne Kobayashi, Ph.D., UI resear
'/>"/>
| Contact: Jennifer Brown jennifer-l-brown@uiowa.edu 319-335-9917 University of Iowa Source:Eurekalert |
Related biology news :
1. Childhood obesity indicates greater risk of school absenteeism, Penn study reveals
2. A study by the MUHC and McGill University opens a new door to understanding cancer
3. Study begins to reveal clues to the cause and progression of sepsis
4. Clones on task serve greater good, evolutionary study shows
5. New study warns limited carbon market puts 20 percent of tropical forest at risk
6. New study examines how rearing environment can alter navigation
7. Study links cat disease to flame retardants in furniture and to pet food
8. New continent and species discovered in Atlantic study
9. Study shows link between alcohol consumption and hiv disease progression
10. Feeling hot, hot, hot: New study suggests ways to control fever-induced seizures
11. Study finds environmental tests help predict hospital-acquired Legionnaires disease risk
| Copyright © 2003-2012 Bio-Medicine. All rights reserved. ABOUT | CONTACT US | DISCLAIMER | PRIVACY POLICY | TERMS AND CONDITIONS |  |