5-hydroxytryptamine-1 receptor activation inhibits endocrine pancreatic secretion in man.. Coulie, Bernard, Jan Tack, Roger Bouillon, Theo Peeters, Jozef Janssens. Center for Gastroenterological Research, Division of Endocrinology, University Hospital Gasthuisberg, Catholic University of Leuven, B -3000 Leuven, Belgium, GI Research Unit, Mayo Foundation, 200 First Street SW, Rochester, MN
APStracts 4:0239E, 1997.
The selective 5-Hydroxytryptamine-1 receptor agonist sumatriptan inhibits exocrine pancreatic function in man. No data are available on the effect of sumatriptan on fasting and postprandial endocrine pancreatic function in man. In order to elucidate the influence of 5 -Hydroxytryptamine-1 receptor activation by sumatriptan on endocrine pancreatic function and blood glucose homeostasis, we determined plasma levels of somatostatin, glucagon, pancreatic polypeptide, insulin, and C-peptide before and after subcutaneous administration of sumatriptan (6 mg) in 7 healthy volunteers and we measured blood glucose and insulin plasma levels during an oral glucose tolerance test after placebo and after subcutaneous administration of sumatriptan (6 mg) in 7 healthy volunteers. Sumatriptan significantly decreased the mean plasma levels of somatostatin, glucagon, pancreatic polypeptide, insulin and C-peptide (p < 0.001), and also significantly decreased mean and peak plasma levels of insulin after an oral glucose challenge (p < 0.02 and p = 0.04 respectively) without affecting glucose homeostasis. From our study, we speculate that activation of the 5-Hydroxytryptamine-1 receptor inhibits endocrine pancreatic secretion. 

Received 16 April 1997; accepted in final form 24 October 1997.
APS Manuscript Number E175-7.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 14 November 1997