Role of adrenergic mechanism in ketogenesis.

Abstract

Ketogenesis is a kind of physiological and biochemical imbalance between glycogenolysis, gluconeogenesis and lipolysis, which are delicately regulated by several hormones. The purpose of these experiments in rats is whether the administration of epinephrine, which has potent actions on glycogenolysis and lipolysis, can make the similar ketogenic state as glucagon or anti-insulin serum and how α- or β-adrenergic blockade acts against the rapid effect of epinephrine. As a result, the three hour infusion of epinephrine raised up plasma glucose rapidly and plasma ketones gradually and increased the ketogenic capacity of liver. On this time liver glycogen was exhausted almost completely and liver carnitine was elevated to the same level of fasted rats. The additional administration of α-adrenergic blockade blunted the effect of epinephrine on plasma glucose, plasma ketones and ketogenic capacity of the liver. On the other hand, the additional administration of β-adrenergic blockade aggravated plasma glucose furthermore and had less effect against epinephrine on plasma ketones and ketogenic capacity of the liver. The elevated liver carnitine with epinephrine was not affected by either α- or β-adrenergic blockade. From these findings, we concluded that the rapid ketogenic effect of epinephrine is mainly mediated by a-adrenergic effect of it.