Cytochrome Oxidase of Skeletal Muscle: Adaptive Response to Chronic Disuse

Abstract

After 4 weeks of skeletal muscle disuse produced with hind-limb casts, the cytochrome oxidase activities were significantly lower in the "red" portions of the rectus femoris and gastrocnemius muscles. However, the cytochrome oxidase activities in the "white" portion of the disused gastrocnemius and in the disused soleus were not significantly different from respective control muscles. These results suggest a decreased aerobic capacity in muscle fibers with high oxidative enzyme activity as a result of immobilization.