Endothelin-1 is a potent constrictor in conductive and resistive coronary arteries.
The action of endothelin-1 (ET-1) in canine and porcine coronary artery ring preparations and perfused canine and porcine myocardium was examined in vitro to determine the site of action of ET-1 in the coronary vasculature. ET-1 had a vasoconstrictor effect that was more potent in smaller diameter ring preparations. The EC50s for both canine and porcine ring preparations decreased with a decrease in vessel diameter and the EC50 of ET-1 in the perfused myocardium was three to four times lower than in the smallest ring preparation. The results suggest that ET-1 may cause cardiac ischemia by constriction of resistive vessels rather than by epicardial coronary artery spasm.
Tippins
J R
JR
Cardiovascular Research Unit, Royal Postgraduate Medical School, Hammersmith Hospital, London, England.
Antoniw
J W
JW
Maseri
A
A
D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects; D004285:Dogs; D016232:Endothelins; D066298:In Vitro Techniques; D010455:Peptides / Q000494:pharmacology*; D010477:Perfusion; D013552:Swine; D014655:Vascular Resistance / Q000187:drug effects; D014662:Vasoconstrictor Agents
D016232:Endothelins; D010455:Peptides; D014662:Vasoconstrictor Agents