The Effect of Glucagon on the Metabolic Rate of Rats

Abstract

The administration of glucagon to intact rats increased their oxygen consumption by as much as 47 per cent. The change was greatest one hour after the administration of glucagon and decreased slowly thereafter. A linear relationship was observed between the percentage increase in the metabolic rate and the logarithm of the dose of glucagon. No correlation could be established between the hyperglycemic action of glucagon and its effect on metabolic rate. The increase in oxygen consumption produced by glucagon was similar in magnitude and duration to the change affected by adrenalin. The administration of glucagon and adrenalin together caused a greater increase than that produced by giving optimal amounts of only one of these substances. The effect of glucagon on respiratory metabolism was abolished after thyroidectomy and adrenalectomy had been performed. Its action appeared to be independent of the adrenal medulla since oxygen consumption was stimulated in adrenal-demedullated rats and in adrenalectomized rats treated with cortisone. Adrenalectomy also diminished the effect of adrenalin on the metabolic rate by 60 per cent. The administration of cortisone potentiated the effects of both glucagon and adrenalin. The significance of the similarity between the calorigenic action of glucagon and adrenalin are briefly discussed.