Monosaccharide transport in rat diaphragm muscle.

Abstract

THE passage of glucose across the muscle cell membrane appears to be a major site for regulation of glucose uptake in this tissue. Accelerating effects on glucose uptake both of insulin and of factors such as anoxia which inhibit oxidative phosphorylation appear to result in skeletal and cardiac muscle from an enhanced rate of transfer of the sugar across the muscle cell membrane1–4. Recent studies5 have emphasized that the movement of sugars across the cell membrane is predominantly a transport process, that is, it involves combination of the sugar with a particular constituent of the cell. In the present investigation we have sought to define the specificity of monosaccharide transport systems in diaphragm by determining which monosaccharides compete for transport and to obtain information about the nature of the system by studying the effect of certain enzyme inhibitors on transport of monosaccharides.