Endothelin-1-induced constriction in the coronary resistance vessels and abdominal aorta of the guinea pig

Anne Folta, Irving G. Joshua, R. Clinton Webb

Research output: Contribution to journalArticle

2 Scopus citations

Abstract

The purpose of this study was to examine contractile properties of endothelin-1, a newly discovered vasoactive peptide, in guinea pig coronary resistance vessels and abdominal aorta. Changes in perfusion pressure after injections of endothelin-1 were measured using a constant-flow modified Langendorff preparation. The ED10 values of coronary perfusion pressure were about 100-fold less for endothelin-1 than for prostaglandin F. After the endothelium was damaged by exposure to free radicals, maximal coronary constriction in response to endothelin-1 (10-9 moles) was not altered, whereas dilator responses to low doses of endothelin-1 were converted to constrictor responses. Removal of the endothelium from aortic rings significantly increased responsiveness to endothelin-1 and the maximal response to the peptide. In calcium-free medium, endothelin-1 induced small increases both in perfusion pressure in coronary vessles and in tension in the aorta. Reintroduction of calcium in the coronary and aortic preparations produced a rapid increase in perfusion pressure and tension, respectively. Further, endothelin-1-induced coronary constriction was inhibited 59%±7% by nifedipine (10-7 moles). We conclude that endothelin-1 is a more potent constrictor than prostaglandin F in the coronary vasculature. Endothelin-1-induced constriction in the coronary vasculature of the guinea pig is not mediated through an endogenous constricting factor released from the endothelium or a constrictor prostaglandin. Further, endothelin-1-induced dilation in the coronary vasculature and attenuation of endothelin-1-induced contraction in the abdominal aorta of the guinea pig are mediated through the release of a factor from the endothelium. Endothelin-1-induced coronary constriction and abdominal aortic contraction require extracellular calcium, entering, in part, through nifedipine-sensitive channels.

Original languageEnglish (US)
Pages (from-to)206-211
Number of pages6
JournalHeart and Vessels
Volume5
Issue number4
DOIs
StatePublished - Dec 1 1990

Keywords

  • Calcium
  • Nifedipine
  • Vascular endothelium

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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