The Inhibitory Effect of Somatostatin on Growth Hormone, Insulin and Glucagon Secretion in Diabetes Mellitus1

Abstract

The inhibitory effect of somatostatin on insulin, glucagon and growth hormone secretion was studied in 5 patients with diabetes mellitus. In three maturity onset diabetics, somatostatin infusion abolished the insulin rise induced by breakfast and oral glucose, and in 2 of them, inhibited the basal insulin secretion by 50% seen during control studies. Concomitantly, there was a marked and prompt reduction of glucagon levels (50%) with a sustained effect. The plasma glucose levels were either unchanged or slightly increased. Following the somatostatin infusion, there was a prompt rebound increase in both insulin and glucagon levels with a relatively stable plasma glucose concentration. In contrast, a drastic reduction of plasma glucose in face of a relatively small fall in plasma glucagon in response to somatostatin infusion was observed in 2 insulin dependent diabetics. In all patients, the episodic release of growth hormone seen during the control day was abolished during somatostatin infusion.