Galactose metabolism by the isolated rat diaphragm.

Abstract

Insulin sensitive uptake of galactose by the isolated rat diaphragm has been confirmed. Substrate competition studies using radiocarbon-labeled sugars indicate that galactose has no effect on either the uptake or oxidation of glucose. Glucose lowers galactose uptake slightly and reduces the oxidation of galactose by 25%. Glucose drastically depresses the oxidation and uptake of fructose, while galactose has a negligible effect on fructose. The distribution of C14 in the diaphragm from glucose and galactose was compared. Glucose-C14 activity was found in the metabolic products such as glycogen, CO2, organic phosphates and other products. Most of the radioactive galactose was found in the free form. The small amounts of radioactivity found in the respired CO2, glycogen and organic phosphates do indicate that galactose can be metabolized by the muscle cells.