Glucagon-like peptide-1 can reverse the age-related decline in glucose tolerance in rats - PubMed (original) (raw)

Y Wang et al. J Clin Invest. 1997.

Abstract

Wistar rats develop glucose intolerance and have a diminished insulin response to glucose with age. The aim of this study was to investigate if these changes were reversible with glucagon-like peptide-1 (GLP-1), a peptide that we have previously shown could increase insulin mRNA and total insulin content in insulinoma cells. We infused 1.5 pmol/ kg-1.min-1 GLP-1 subcutaneously using ALZET microosmotic pumps into 22-mo-old Wistar rats for 48 h. Rat infused with either GLP-1 or saline were then subjected to an intraperitoneal glucose (1 g/kg body weight) tolerance test, 2 h after removing the pump. 15 min after the intraperitoneal glucose, GLP-1-treated animals had lower plasma glucose levels (9.04+/-0.92 mmol/liter, P < 0.01) than saline-treated animals (11.61+/-0.23 mmol/liter). At 30 min the plasma glucose was still lower in the GLP-1-treated animals (8.61+/-0.39 mmol/liter, P < 0.05) than saline-treated animals (10.36+/-0.43 mmol/liter). This decrease in glucose levels was reflected in the higher insulin levels attained in the GLP-1-treated animals (936+/-163 pmol/liter vs. 395+/-51 pmol/liter, GLP-1 vs. saline, respectively, P < 0.01), detected 15 min after glucose injection. GLP-1 treatment also increased pancreatic insulin, GLUT2, and glucokinase mRNA in the old rats. The effects of GLP-1 were abolished by simultaneous infusion of exendin [9-39], a specific antagonist of GLP-1. GLP-1 is therefore able to reverse some of the known defects that arise in the beta cell of the pancreas of Wistar rats, not only by increasing insulin secretion but also by inducing significant changes at the molecular level.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Biochemistry. 1974 Jun 4;13(12):2633-7 - PubMed
    1. Mol Endocrinol. 1996 Nov;10(11):1327-34 - PubMed
    1. Endocrinology. 1985 Jan;116(1):11-6 - PubMed
    1. Proc Natl Acad Sci U S A. 1987 May;84(10):3434-8 - PubMed
    1. J Clin Invest. 1988 Jan;81(1):176-84 - PubMed

MeSH terms

Substances

LinkOut - more resources