title: Role of endothelin in spontaneous phasic contraction of human coronary arteries.
abstract: Isolated human coronary arteries are known to develop spontaneous phasic contractions (SPCs). The goal of the present study was to assess the role of endothelin (ET) in these contractions. Endothelium-denuded rings from left anterior descending (LAD) coronary arteries of patients with coronary artery disease (CAD; n = 3) undergoing cardiac transplantation developed SPCs within 1-2 h. The contractions were abolished by the ETA receptor antagonist BQ-123 or the mixed ET receptor antagonist bosentan (1 and 3 microM), whereas the contractions persisted for several hours in control rings. Exogenous ET-1 (10 pM) increased the amplitude of SPCs and initiated SPCs in rings that did not exhibit SPCs. Higher concentrations of ET-1 (> or = 1 nM) were able to re-induce SPC in rings in which SPCs had been abolished by BQ-123 or bosentan. These results suggest that ET plays an important role in spontaneous phasic contractions of isolated human coronary artery rings.
authors.affiliation: Pharma Division, F. Hoffmann-La Roche Ltd., Basel, Switzerland.
authors.forename: P H
authors.initials: PH
authors.lastname: Dagassan
authors.forename: M
authors.initials: M
authors.lastname: Clozel
authors.forename: V
authors.initials: V
authors.lastname: Breu
authors.forename: J P
authors.initials: JP
authors.lastname: Clozel
mesh_terms: D003331:Coronary Vessels / Q000502:physiology*; D016232:Endothelins / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000494:pharmacology; D017466:Receptors, Endothelin / Q000502:physiology; D014661:Vasoconstriction
chemical_list: D016232:Endothelins; D010456:Peptides, Cyclic; D017466:Receptors, Endothelin; C072247:cyclo(Trp-Asp-Pro-Val-Leu)