Increased Muscle Permeability to Aldolase Produced by Depolarization and by Metabolic Inhibitors

Abstract

Aldolase leak from rat peroneus longus muscle is assumed to occur by diffusion and its magnitude is taken to be an index of membrane permeability. Aldolase efflux is increased by high external K concentration, presumably owing to membrane depolarization. Mg lack may be slightly effective. Metabolic inhibitors, iodoacetate, dinitrophenol or cyanide, markedly increase aldolase efflux. These observations, with earlier ones on the effects of anoxia and of glucose lack, suggest that muscle membrane is labile, its permeability linked to cellular metabolism. A dynamic model of muscle membrane is proposed in which sites through which diffusion can occur ripple over the cell surface.