Endothelin- and neuropeptide Y-induced vasoconstriction of human epicardial coronary arteries in vitro.
1. The effects of the recently discovered peptide endothelin and neuropeptide Y (NPY) on human epicardial coronary arteries were studied in vitro. 2. Endothelin induced a concentration-dependent, endothelium-independent, long-lasting vasoconstriction regardless of vessel size. NPY evoked contractions of small coronary arteries with a similar potency to that of endothelin, although to a significantly lower degree. Large coronary arteries did not respond to NPY. Endothelin did not relax coronary arteries precontracted with potassium. 3. The effect of endothelin was dependent on extracellular Ca2+ and, like NPY, significantly reduced by the Ca2+-antagonist nifiedipine. 4. In conclusion, endothelin is a potent human vasoconstrictor in vitro. It is suggested that endothelin may be involved in the regulation of coronary blood flow.
Franco-Cereceda
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Department of Pharmacology, Karolinska Institutet, Stockholm, Sweden.
D000328:Adult; D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects; D016232:Endothelins; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009478:Neuropeptide Y / Q000494:pharmacology*; D010455:Peptides / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology; D013552:Swine; D014661:Vasoconstriction / Q000187:drug effects*
D016232:Endothelins; D009478:Neuropeptide Y; D010455:Peptides; D011188:Potassium