Effects of somatostatin on plasma glucose and glucagon levels in human diabetes mellitus. Pathophysiologic and therapeutic implications.

Abstract To evaluate the role of pancreatic alpha-cell dysfunction in human diabetes mellitus, somatostatin, an inhibitor of glucagon secretion, was infused (1 mg over two hours) in 10 insulin-dependent diabetic subjects. Fasting plasma glucagon fell from 150 ± 15 (mean ± S.E.M.) to 77 ± 10 pg per milliliter (p<0.001), and plasma glucose from 260 ± 20 to 191 ± 21 mg per 100 ml (p<0.001). Similar responses occurred in a hypophysectomized diabetic patient, indicating that these effects of somatostatin were independent of suppression of growth hormone secretion. Somatostatin (4 mg subcutaneously) was active transiently. In additional studies, somatostatin infusion combined with insulin completely abolished post-meal hyperglycemia in four diabetic patients and was more effective than insulin alone. These results indicate that excessive glucagon secretion accounts for about 25 per cent of the fasting plasmaglucose levels in such patients. Furthermore, somatostatin may be a useful adjunct to insulin in treating...