Effect of Insulin on the Synthesis of Glycogen in Cerebral Cortical Slices of Alloxan Diabetic Rats

Synthesis of glycogen in cerebral cortical slices of alloxan diabetic rats could not be demonstrated with glucose as the substrate. Intravenous administration of insulin gave rise to synthesis of glycogen in these slices with the same substrate. Addition of insulin to the medium also produced a striking synthesis of glycogen in such slices. Slices of cerebral cortex ofdiabetic rats synthesized glycogen in the presence of 5 DIM sodium pyruvate and 5 mM sodium acetate, while normal slices did not. Glucose-6- phosphatase activity in the cerebral cortical slices of the normal rat, which is 1/5 of that of normal liver, is reduced almost to insignificant levels in the diabetic condition. {Endocrinology 82: 1, 1968)