Contractile effect of endothelin in the human uterine artery and autoradiographic localization of its binding sites.
OBJECTIVE
The aim was to study the effects, mode of action, and binding sites of endothelin-1 in the human uterine artery.


METHODS
The contractile effect of endothelin-1 on the human uterine artery with and without endothelium and the effect of verapamil and nicardipine on the contraction was investigated in vitro. The Student t test was used. Iodine 125-endothelin-1 binding sites were localized with autoradiography.


RESULTS
Endothelin-1 induced a contraction that was unaffected by removal of the endothelium. Verapamil antagonized the contraction, whereas nicardipine showed no effect. Iodine 125-endothelin-1 binding sites were demonstrated in the smooth muscle layer.


CONCLUSIONS
These results show that endothelin-1 is a vasoconstrictor in the human uterine artery and suggest that the effect is mediated by receptors on the smooth muscle cells. The mode of action seems to involve Ca++ influx by other than dihydropyridine-sensitive Ca++ channels. Endothelin-1 does not seem to stimulate release of other endothelium-derived vasoactive agents.
Bodelsson
G
G
Department of Obstetrics and Gynecology, University of Lund, Malmö.
Sjöberg
N O
NO
Stjernquist
M
M
D000328:Adult; D000368:Aged; D001158:Arteries / Q000187:drug effects / Q000378:metabolism; D001345:Autoradiography; D001665:Binding Sites; D002121:Calcium Channel Blockers / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D016232:Endothelins / Q000378:metabolism / Q000494:pharmacology*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008875:Middle Aged; D009994:Osmolar Concentration; D014018:Tissue Distribution; D014599:Uterus / Q000098:blood supply*; D014661:Vasoconstriction
D002121:Calcium Channel Blockers; D016232:Endothelins