Endothelin ETA and ETB receptors mediate vascular smooth muscle contraction

Br J Pharmacol. 1992 Nov;107(3):858-60. doi: 10.1111/j.1476-5381.1992.tb14537.x.

Abstract

1. We have investigated the receptors mediating endothelin-induced contraction of rabbit isolated jugular vein (RJV) and rat isolated thoracic aorta (RTA). 2. Endothelin-1 (ET-1) and endothelin-3 (ET-3) contracted RJV preparations with similar potency (EC50 values approximately 1 nM), whereas, ET-1 (EC50:4.5 nM) was approximately 80 fold more potent than ET-3 in contracting RTA. In addition, the ETB receptor-selective agonist [Ala1,3,11,15]ET-1 contracted RJV (EC50:2.1 nM) but not RTA. 3. The ETA receptor antagonist, BQ123, competitively antagonized (pA2 6.93) the contraction of RTA produced by ET-1, but had no effect (at 10 microM) on the contractile effects of either ET-1, ET-3 or [Ala1,3,11,15]ET-1 in RJV. 4. These data suggest that both ETA and ETB receptors can mediate vascular smooth muscle contraction.

MeSH terms

  • Animals
  • Aorta, Thoracic / drug effects
  • Endothelins / pharmacology
  • In Vitro Techniques
  • Isometric Contraction / drug effects
  • Jugular Veins / drug effects
  • Muscle Contraction / drug effects
  • Muscle, Smooth / drug effects*
  • Muscle, Smooth, Vascular / drug effects
  • Peptides, Cyclic / pharmacology*
  • Rabbits
  • Receptors, Endothelin / drug effects*

Substances

  • Endothelins
  • Peptides, Cyclic
  • Receptors, Endothelin
  • cyclo(Trp-Asp-Pro-Val-Leu)