Enzymatic Changes in Denervated Muscle: II. Biochemical Studies

Introduction  THE DIFFERENCES in mammalian skeletal muscle metabolism with higher lactic acid production in white muscle^13,17,18 and increased oxygen consumption^2,10,37 and carbon dioxide evolution³ in red muscle indicate a greater reliance of the former upon anaerobic reactions for the production of energy, and of the latter upon aerobic mechanisms. The demonstration by Lawrie^29,30 of the direct relationship between the activity of the cytochrome system and the content of myoglobin in striated muscle focused attention upon the variation in enzyme activity with pigmentation. Bücher and his colleagues^7,39 studying several enzymes in the skeletal muscles of rabbits and rats have shown distributions of enzyme activities favoring glycolysis in white muscles and oxidative processes in red. Recent studies from this laboratory^8,42 with histochemical and quantitative methods showed such enzymatic differences not only between different muscles, but between various types of muscle fibers within a muscle.