LAUSR

Previous studies have shown increased mitochondrial generation of peroxides in denervated muscle fibers, but the role that peroxides play during denervation is still controversial. The Anterior Tibialis and Extensor Digitorum Longus muscles of wild type and Thy-1YFP mice were denervated by surgical removal of a small section of the peroneal nerve. Western blotting and immunohistochemical techniques were used to examine protein contents along with analysis of morphological changes and mitochondrial peroxide release following denervation. Data indicate that increased peroxide generation is maintained up to 21 days following denervation and is associated with a significant increase in the muscle contents of Peroxiredoxin 6 and Phospholipase A2 involved in the activation of NADPH Oxidase. A significant increase in the contents of several antioxidant enzymes and HSPs involved in the protection against oxidative damage was also observed. These results support the possibility that (at least initially) an increase in mitochondrial peroxide production may stimulate adaptation and repair processes in the neuromuscular system but sustained increased peroxide generation over the longer term lead to degeneration and muscle atrophy.