Mitochondrial oxygen consumption, lipid peroxidation and antioxidant enzyme systems in skeletal muscle of senile dystrophic mice.
To evaluate age-dependent abnormalities in mitochondrial redox metabolism specifically in dystrophic skeletal muscle, oxygen consumption, thiobarbituric acid reactivity (TBARS), free-radical scavengers and oxidative marker enzymes were measured in the skeletal muscle from adult and senile control (C57BL/10) and dystrophic (mdx/+) mice. Mitochondrial oxygen consumption in state 3 was significantly lowered with age in the senile dystrophic (-52%) and less markedly in the senile control (-30%) skeletal muscle. Compared with adult muscle, mitochondrial concentration of TBARS and cellular concentration of lipofuscin were significantly increased in senile control and dystrophic muscle. Enzymatic activity of glutathione peroxidase (GSH-Px) and concentration of alpha-tocopherol were significantly increased in the senile control (GSH-Px 43+/-5.7 vs 53+/-8.7 U/g protein, alpha-tocopherol 0.19+/-0. 09 vs 0.29+/-0.14 micromol/g total lipids), but significantly decreased in the senile dystrophic (GSH-Px 80+/-8.0 vs 53+/-12 U/g protein, alpha-tocopherol 0.45+/-0.13 vs 0.19+/-0.03 micromol/g total lipids) muscle. Selenium content was significantly decreased only in senile dystrophic muscle (1.37+/-0.42 vs 0.78+/-0.21 nmol/g wet muscle). In conclusion, the enzymatic adaptation to reactive oxygen species was limited in the dystrophic skeletal muscle, suggesting a higher need for antioxidants, especially alpha-tocopherol.
Faist
V
V
Institute of Nutrition, University of Vienna, Vienna, Austria. vfaist@nutrfoodsc.uni-kiel.de
Koenig
J
J
Hoeger
H
H
Elmadfa
I
I
D000375:Aging; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D016166:Free Radical Scavengers; D005979:Glutathione Peroxidase / Q000378:metabolism; D015227:Lipid Peroxidation; D051379:Mice; D008810:Mice, Inbred C57BL; D008928:Mitochondria / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000648:ultrastructure*; D009137:Muscular Dystrophy, Animal / Q000378:metabolism*; D010101:Oxygen Consumption; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014810:Vitamin E / Q000378:metabolism
D000975:Antioxidants; D016166:Free Radical Scavengers; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase