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Nitric oxide and voluntary exercise together promote quadriceps hypertrophy and increase vascular density in female 18-mo-old mice.
- Source :
-
American Journal of Physiology: Cell Physiology . May2012, Vol. 302 Issue 9, pC1306-C1315. 10p. - Publication Year :
- 2012
-
Abstract
- Age-related sarcopenia reduces the size, strength, and function of muscle, and the diameter of muscle fibers. It also disrupts the dystrophin-glycoprotein complex, dislocating nitric oxide synthase 1 (NOS-1) and reducing sarcolemmal integrity. This study of quadriceps muscle in 18-mo-old mice showed that NO-donor treatment with isosorbide dinitrate (I) for 6 wk, in combination with voluntary exercise for 3 wk, increased muscle mass by 25% and stimulated cell proliferation. The resulting fiber hypertrophy was accompanied by a lower ratio of protein:DNA, consistent with myogenic-cell hyperplasia. Treatment enhanced the ratio of NOS-1:β-dystroglycan in correlation with fiber diameter, improved sarcolemmal integrity, and increased vascular density after an increase in vascular endothelial growth factor protein at 3 wk. Results demonstrate that age-related muscle refractoriness to exercise can be overcome with NO-donor treatment. Since activation of muscle stem cells and vascular perfusion are limiting factors in the maintenance, regeneration, and growth of aged muscle, results suggest the feasibility of using NO-donor drugs to combat atrophy and muscle ischemia. Improved function and quality of life from the NO-amplified effects of exercise may be useful in aging and other conditions such as disuse, insulin resistance, or microgravity. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 03636143
- Volume :
- 302
- Issue :
- 9
- Database :
- Academic Search Index
- Journal :
- American Journal of Physiology: Cell Physiology
- Publication Type :
- Academic Journal
- Accession number :
- 95873883
- Full Text :
- https://doi.org/10.1152/ajpcell.00305.2011