Effect of Adrenaline and Noradrenaline on Carbohydrate Metabolism of Rat Diaphragm

Abstract

It has been shown by the authors that adrenaline in vitro causes glycogen breakdown, decreases glucose utilization and increases lactic acid formation in the isolated rat diaphragm.¹ In continued experiments it has been shown (unpublished experiments by E. Walaas) that this change in carbohydrate balance of the diaphragm is due to two different effects. Thus, the primary effects of adrenaline on muscle metabolism are: I. Glycogen is broken down. II. Peripheral utilization of glucose is decreased. This explains recent observations in humans on the effect of adrenaline on carbohydrate metabolism. ²The effect of noradrenaline on carbohydrate metabolism of the isolated rat diaphragm has also been studied.³ It was observed that 1-noradrenaline as well as d,1-noradrenaline decreased glucose utilization and glycogen formation when these compounds were added to the incubation medium in vitro. As far as the effect on glycogen synthesis is concerned the activity of l-noradrenaline was 1/5 and of d,1-noradrenaline 1/15 of the activity obtained by adrenaline. The relative effects on glucose utilization by the three compounds were of the same order of magnitude. (A complete report will be published elsewhere.)