Inhibitory Action of High Levels of Glucose on Glucagon Effects in the Isolated Perfused Rat Liver 1

Abstract

Summary

Livers obtained from fasted rats were perfused with whole blood obtained from fasted rats and were found to release small amounts of glucose to the effluent. The addition of glucose to the perfusing medium resulted in glucose uptake by the liver. When glucagon was added to the perfusate, glucose was released into the effluent. In these studies the effects of a combined glucose and glucagon infusion into livers from fasted rats were tested. The catabolic effects of a supra-physiological concentration (6 × 10^-9 M) of glucagon on liver metabolism of carbohydrates, fats and proteins were significantly rreduced when glucose was also added to the perfusate. Thes, a high glucose concentration in the perfusate overrides the usual effects of glucagon on “fasted” liver cells.