Enzyme Studies in Muscular Dystrophy. III. In Hereditary Muscular Dystrophy in Mice.

Abstract

Changes in muscle composition, and the activity of 4 enzyme systems in mice with dystrophia muscularis, have been investigated. Total N and protein N contents of dystrophic muscle were reduced as compared to controls, while collagen N was increased. Percentage dry weight was unchanged. Aldolase activity of dystrophic muscle was decreased on the basis of wet or dry weight, but was unchanged on the basis of protein- or non-collagen protein N content of muscle. Succinoxidase activity was not significantly affected by muscle dystrophy. Cytochrome oxidase and cathepsin activities were markedly increased in the muscle of dystrophic mice as compared to controls. Similar investigations of liver tissue from these mice revealed no change as a result of the dystrophy. These results are discussed and compared to those observed in other forms of muscle wasting.