Mechanisms of disuse muscle atrophy: role of oxidative stress.

Prolonged periods of skeletal muscle inactivity lead to a loss of muscle protein and strength. Advances in cell biology have progressed our understanding of those factors that contribute to muscle atrophy. To this end, abundant evidence implicates oxidative stress as a potential regulator of proteolytic pathways leading to muscle atrophy during periods of prolonged disuse. This review will address the role of reactive oxygen species and oxidative stress as potential contributors to the process of disuse-mediated muscle atrophy. The first section of this article will discuss our current understanding of muscle proteases, sources of reactive oxygen in muscle fibers, and the evidence linking oxidative stress to disuse muscle atrophy. The second section of this review will highlight gaps in our knowledge relative to the specific role of oxidative stress in the regulation of disuse muscle atrophy. By discussing unresolved issues and suggesting topics for future research, it is hoped that this review will serve as a stimulus for the expansion of knowledge in this exciting field.