Comparison of the effects of glucagon-like peptide-1-(1-37) and -(7-37) and glucagon on islet hormone release from isolated perfused canine and rat pancreases

Endocrinology. 1989 Apr;124(4):1768-73. doi: 10.1210/endo-124-4-1768.

Abstract

Recently, it has been demonstrated that glucagon-like peptide-1 (GLP-1)-(7-37) possesses a potent insulinotropic activity. In this paper, we compared the effects of GLP-1-(1-37) and -(7-37) and glucagon on insulin, glucagon, and somatostatin release from isolated perfused canine and rat pancreases under the perfusate condition of 5.5 mM glucose plus arginine. With canine pancreas perfusion, 1 nM GLP-1-(7-37) was more potent in stimulating insulin and somatostatin release than was the same dose of glucagon [stimulation to 375 +/- 36% vs. 302 +/- 28% of the basal level for insulin (P less than 0.05); 724 +/- 129% vs. 311 +/- 33% of the basal level for somatostatin (P less than 0.01)]. GLP-1-(1-37) (1 nM) did not stimulate either insulin or somatostatin release. GLP-1-(7-37) (1 nM) decreased the glucagon level of the effluent perfusate to 67.2 +/- 3.4% of its basal level; but 1 nM GLP-1-(1-37) did not. Glucagon (1 nM) decreased GLP-1-like immunoreactivity to 64.0 +/- 5.2% of its basal level. With rat pancreatic perfusion, the minimal dose for stimulation of insulin release was 100 nM for GLP-1-(1-37), 0.1 nM for GLP-1-(7-37), and 1 nM for glucagon, respectively. Glucagon release was partially inhibited by 100 nM GLP-1-(1-37) and 1 and 10 nM GLP-1-(7-37). The present results indicate that 1) since GLP-1-(7-37) is released from the intestine, it might be an important incretin candidate along with gastric inhibitory peptide; and 2) the release of proglucagon-derived peptides from pancreatic A-cells is regulated by autofeedback through glucagon and GLP-1.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Separation
  • Dogs
  • Dose-Response Relationship, Drug
  • Glucagon / metabolism
  • Glucagon / pharmacology*
  • Glucagon-Like Peptide 1
  • Glucagon-Like Peptides
  • Insulin / metabolism
  • Islets of Langerhans / metabolism*
  • Male
  • Pancreas / cytology
  • Pancreas / metabolism
  • Peptide Fragments
  • Peptides / metabolism
  • Peptides / pharmacology*
  • Perfusion
  • Rats
  • Rats, Inbred Strains
  • Somatostatin / metabolism

Substances

  • Insulin
  • Peptide Fragments
  • Peptides
  • Somatostatin
  • Glucagon-Like Peptides
  • glucagon-like peptide 1 (1-37)
  • Glucagon-Like Peptide 1
  • Glucagon
  • glucagon-like peptide 1 (7-37)