APStracts 2:0128G, 1995.

Intra islet regulation of hormone secretion by glucagon-like peptide-1 (7-36) amide. Heller, R. Scott, and Gregory W. Aponte. Department of Nutritional Sciences, University of California, Berkeley, Berkeley, CA 94720

APStracts 2:0128G, 1995.

GLP-1 (7-36) amide, a peptide product of the post-translational processing of pancreatic and intestinal proglucagon, has been shown to regulate insulin secretion. Monoclonal antibodies to glucagon and GLP-1 (7-36) amide were generated to localize GLP-1 (7-36) amide in the pancreatic islets by immunocytochemistry and radioimmunoassay. GLP-1 (7-36) amide immunoreactivity was found in some, but not all glucagon containing [alpha]-cells. Displaceable receptor binding for GLP-1 (7-36) amide was found on cells immunoreactive for insulin, somatostatin, glucagon and GLP-1. Direct effects of GLP-1 (7-36) amide and non amidated GLP-1 (7-37) on hormone secretion were investigated using isolated pancreatic islet preparations. GLP-1 (7 -37) and (7-36) amide significantly increased insulin and somatostatin release in the concentration range of 0.01 to 100 nM in 11.0 mM glucose. GLP-1 (7-37) and (7-36) amide had no effect on glucagon secretion in the presence of 11.0 mM glucose. GLP-1 (7-36) amide was released from isolated islets in response to 2.25, 5.5 and 11.0 mM glucose. These results suggest that pancreatic GLP-1 may be important in the regulation of intra islet hormone secretion.

Received 8 September 1994; accepted in final form 13 June 1995.
APS Manuscript Number G344-4.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 11 July 1995.