Effect of endothelin-1 on arterioles and venules in vivo.
The vasoconstrictor effects of endothelin-1 (ET-1) and norepinephrine (NE) were compared in the exteriorized rat mesentery in situ. ET-1 was 1,000 times more potent than NE in constricting both arterioles and venules. Vasoconstrictions induced by ET-1 lasted much longer than those caused by the catecholamine. At nonrelaxant doses, acetylcholine and sodium nitroprusside antagonized the constrictive response of microvessels to ET-1 and NE. However, larger doses of acetylcholine were necessary to inhibit the response to ET-1 than that to NE.
Fortes
Z B
ZB
Department of Pharmacology, University of São Paulo, Brazil.
de Nucci
G
G
Garcia-Leme
J
J
D000818:Animals; D001160:Arterioles / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D016232:Endothelins; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects; D008642:Mesenteric Veins / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D014661:Vasoconstriction / Q000187:drug effects; D014699:Venules / Q000187:drug effects
D016232:Endothelins; D010455:Peptides; D009638:Norepinephrine