Effect of Glucagon-Like Peptide-1 on Gastric Somatostatin and Gastrin Secretion in the Rat

Abstract

The effect of glucagon-like peptide-1 (GLP-1) amide on gastric somatostatin and gastrin secretion was investigated in the isolated, vascularly perfused rat stomach preparation. GLP-1 (7-36) amide, 10⁻¹²to 10⁻⁷M, dose-dependently increased gastric somatostatin release, achieving maximal stimulation (314 ± 15% above basal) at the highest dose. The somatostatin response to 10⁻⁸ M GLP-1 (7-36) amide was not affected by concomitant perfusion with tetrodotoxin. GLP-1 (1-36) amide did not affect somatostatin release. Both basal and acetylcholine-stimulated gastrin were inhibited by GLP-1 (7-36) amide but were not influenced by GLP-1 (1-36) amide. It is concluded that GLP-1 (7-36) amide is the biologically effective peptide that stimulates gastric somatostatin and inhibits gastrin secretion, probably via non-neural pathways. GLP-1 (7-36) amide-induced inhibition of gastric acid secretion may, at least in part, be due to enhanced somatostatin and/or decreased gastrin release.

Key Words:

• Gastrin
• glucagon-like peptide-1
• rat
• somatostatin
• stomach