Galactose metabolism by the isolated rat diaphragm.

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 C 14 in the diaphragm from glucose and galactose was compared. Glucose-C 14 activity was found in the metabolic products such as glycogen, CO 2 , 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 CO 2 , glycogen and organic phosphates do indicate that galactose can be metabolized by the muscle cells.