The activity of peptides of the endothelin family in various mammalian smooth muscle preparations

Eur J Pharmacol. 1989 Dec 12;174(1):23-31. doi: 10.1016/0014-2999(89)90869-8.

Abstract

The activity of natural endothelins such as ET-1, ET-2, ET-3 and of sarafotoxin S6b (SRFTX) as compared to that of the C-terminal hexapeptide ET-(16-21) was investigated in several smooth muscle preparations in the presence of indomethacin, captopril, bestatin and thiorphan. In some tissues (rat thoracic aorta, guinea-pig ileum, human urinary bladder, renal pelvis or renal artery), ET-(16-21) had little if any agonist activity. In other preparations (guinea-pig bronchus, rat vas deferens, rabbit pulmonary artery) ET-(16-21) was a full agonist. The amidated form of ET-(16-21) was either inactive or less potent than ET-(16-21). These findings provide evidence that at least two receptors exist for peptides of the ET family; these receptors were termed ETA and ETB. ET-(16-21) is a full agonist at ETB receptors while being inactive or weakly active at ETA receptors. The free acid of tryptophan in position 21 plays a key role in the activity of these peptides at ETB receptors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Electric Stimulation
  • Endothelins
  • Guinea Pigs
  • Humans
  • In Vitro Techniques
  • Indomethacin / pharmacology
  • Male
  • Muscle Contraction / drug effects
  • Muscle, Smooth / drug effects*
  • Muscle, Smooth / physiology
  • Muscle, Smooth, Vascular / drug effects
  • Peptide Fragments / pharmacology
  • Peptides / pharmacology*
  • Rabbits
  • Rats
  • Rats, Inbred Strains
  • Vasoconstrictor Agents / pharmacology
  • Viper Venoms / pharmacology

Substances

  • Endothelins
  • Peptide Fragments
  • Peptides
  • Vasoconstrictor Agents
  • Viper Venoms
  • sarafotoxins s6
  • Indomethacin