STUDIES ON THE MECHANISM OF SOMATOSTATIN ACTION ON INSULIN RELEASE IN MAN

Abstract

ABSTRACT Somatostatin in as small a dose as 70 μg given over a period of 90 min to seven healthy subjects inhibited insulin release induced by glucose (500 mg/kg as a bolus ± 20 mg/kg/min). This inhibition seemed to be of competitive nature since the effect was nearly overcome when the glucose dose was raised considerably. Somatostatin in nine subjects also inhibited insulin release induced by glucagon and tolbutamide, and this inhibition was of the same order of magnitude as that of glucose induced insulin release. Since all these insulinogogues enhance the accumulation of cyclic AMP in the β-cells, it is suggested that the adenylate cyclase-cyclic AMP system might be involved in the action of somatostatin. Somatostatin did not seem to interfere with the glycogenolytic effect of glucagon on the liver.