The effect of age on hormonally-stimulated glycogenolysis in isolated rat hepatocytes

Abstract Effects of glucagon and epinephrine stimulation on glycogen degradation in hepatocytes isolated from fed young, adult and old rats were studied. At three concentrations used, glucagon increased glycogenolysis to the same extent in liver cells of all groups of rats. Epinephrine stimulated glycogen degradation to a significantly higher degree in hepatocytes of adult and old rats as compared to those of young ones. In all age groups of rats epinephrine acted through stimulation of α-adrenergic receptors. On the basis of this and a previous study (Kmiec and Mysliwski, Exp. Gerontol. (1983) 18, 173) it may be concluded that age-dependent changes in the effects of catecholamines and glucagon on carbohydrate metabolism in rat liver parenchymal cells are related to specific hormonal effects on a given metabolic pathway and to the nutritional status of the animals.