FACTORS INFLUENCING THE DISTRIBUTION OF PENTOSES IN THE ISOLATED RAT DIAPHRAGM

Abstract

The addition of insulin, or of various enzyme inhibitors, to the intact isolated rat diaphragm causes an increase in pentose space, without causing a corresponding increase in inulin space or in total water. It is suggested that there is a relationship between cellular metabolism and permeability to pentoses. If pentose permeability and glucose permeability are governed by similar mechanisms, this means the glucose permeability might depend on cellular metabolism. However, phenethylbiguanide and pyruvate do not increase the permeability to pentoses, though they do increase glucose uptake. This means that glucose uptake might be increased without a corresponding increase in glucose permeability. Glucose utilization therefore may be governed by several factors of which the cellular permeability is only one.