Dissociation of potassium and glucose efflux in isolated perfused rat liver.

BURTON, STANLEY D., CARL E. MONDON, AND TADASHI ISHIDA. Dissociation of potassium and glucose e$lux in isolated perfused rat I iver. Am. J. Physiol. 212(2) : 261-266. Ig67.-The dissociation of potassium and glucose movement during glucagon-induced glycogenolysis was studied in the isolated rat liver utilizing a small volume perfusion apparatus. When glucagon was added to a preparation assumed to be insulin deficient and depleted of a fraction of liver K+ after 6o-min perfusion, a marked outflow of glucose occurred in the absence of an early efflux of liver K f. However, when glucagon was administered to a liver pretreated with insulin to restore intracellular K+, a large efflux of potassium occurred during the onset of glycogenolysis. The administration of insulin after glucagon effected a recovery of potassium previously lost from the liver and reduced the outflow of glucose. These findings indicate that a fraction of potassium dependent upon insulin for retention within the liver moves independently of glucose and suggests that the early release of potassium during glucagon-induced glycogenolysis involves an inhibition of the effect of insulin on maintaining potassium within the cell.