Glucagon-like peptide-1 relaxes rat conduit arteries via an endothelium-independent mechanism

Regul Pept. 2005 Feb 15;125(1-3):173-7. doi: 10.1016/j.regpep.2004.08.024.

Abstract

A lot of interest has engendered in glucagon-like peptide-1 (GLP-1) as an emerging new drug in the treatment of type 2 diabetes. GLP-1 exerts several effects that reduce glycemia in type 2 diabetes patients. We recently also demonstrated that GLP-1 ameliorates endothelial dysfunction in type 2 diabetes mellitus patients with established coronary heart disease, suggesting a new important cardioprotective role for GLP-1. Because hypertension is overrepresented in diabetes and is adversely influencing survival, we have now investigated direct GLP-1 effects on vascular beds in a rat organ bath model. It was found that GLP-1 relaxed femoral artery rings in a dose-response manner. The relaxant effect from GLP-1 was completely inhibited by the specific GLP-1 receptor antagonist, exendin(9-39). Neither the specific nitric oxide (NO) synthase inhibitor, N-nitro-L-arginine, nor removing of endothelium, affected the GLP-1 relaxant effect. In conclusion, we now report a direct vascular action of GLP-1, relaxing conduit vessels independently of NO and the endothelium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholine / metabolism
  • Animals
  • Arteries / drug effects*
  • Arteries / metabolism
  • Cardiotonic Agents / pharmacology
  • Cyclic AMP / metabolism
  • Dose-Response Relationship, Drug
  • Endothelium, Vascular / metabolism*
  • Femoral Artery / drug effects
  • Glucagon / metabolism
  • Glucagon / physiology*
  • Glucagon-Like Peptide 1
  • Glucagon-Like Peptide-1 Receptor
  • Male
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase / antagonists & inhibitors
  • Nitroarginine / pharmacology
  • Peptide Fragments / metabolism
  • Peptide Fragments / physiology*
  • Potassium / metabolism
  • Protein Precursors / metabolism
  • Protein Precursors / physiology*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Glucagon / metabolism

Substances

  • Cardiotonic Agents
  • Glp1r protein, rat
  • Glucagon-Like Peptide-1 Receptor
  • Peptide Fragments
  • Protein Precursors
  • Receptors, Glucagon
  • Nitroarginine
  • Nitric Oxide
  • exendin (9-39)
  • Glucagon-Like Peptide 1
  • Glucagon
  • Cyclic AMP
  • Nitric Oxide Synthase
  • Acetylcholine
  • Potassium