FAILURE OF SOMATOSTATIN TO INHIBIT TOLBUTAMIDE-INDUCED INSULIN SECRETION IN PATIENTS WITH INSULINOMAS: A POSSIBLE DIAGNOSTIC TOOL

Abstract

The effects of somatostatin on tolbutamide-stimulated insulin release were studied in 4 patients with insulin-producing tumors of the pancreas and in 6 normal subjects, in contrast to its effective inhibition of insulin release in normal subjects, somatostatin, without exception, failed to inhibit tolbutamideinduced insulin release in the patients with pancreatic £-cell tumors. This differential effect of somatostatin may prove useful in the diagnosis of insulin-producing tumors of the pancreas.