Oxyradical damage and mitochondrial enzyme activities in the mdx mouse.

A number of studies have already been undertaken to investigate involvement of oxyradicals in muscle diseases by means of measurements of oxyradical protective enzymes. We investigated o-tyrosine, which is a biomarker for OH radical damage in vivo, in 10 mdx and 10 control mice. We also measured mitochondrial enzymes in muscle homogenates of 10 mdx and 10 control mice. Mdx mice had significantly elevated values for o-tyrosine, succinat-phenacinmetosulfat oxidoreductase. NADH O2 oxidoreductase and cytochrome C oxidoreductase. Our findings confirm the suggestion that elevated oxyradical production occurs in muscular dystrophies with lack of dystrophin. Furthermore, our results demonstrate that OH radical damage does not impair mitochondrial enzyme activities in the mdx mouse.