SOMATOSTATIN INHIBITS THE PENTAGASTRIN-INDUCED RELEASE OF SERUM CALCITONIN IN MEDULLARY CARCINOMA OF THE THYROID

Abstract

The effect of somatostatin on the secretion of calcitonin was studied in 4 patients with medullary carcinoma of the thyroid (MCT). The basal serum calcitonin level was elevated in all cases. A bolus injection (100 .mu.g) of somatostatin followed by an i.v. infusion (5 .mu.g/min) for 60 min suppressed the basal calcitonin level in 3 of the 4 patients by 24-42%, while it had no inhibitory effect in 1 case. In another experiment, the pentagastrin-stimulated (6 .mu.g/kg s.c.) calcitonin release was partially blocked by a simultaneous i.v. injection of somatostatin (200 .mu.g) in all 4 patients studied. These experiments add human calcitonin to the list of hormones whose release is inhibited by somatostatin.