Endothelin-1 causes vasoconstriction and vasodilation in the blood perfused liver of the dog.
Endothelin-1 (ET-1; 1 pmol-1 nmol) was injected intra-arterially into the canine hepatic artery perfused, in situ, with arterial blood. The characteristic arterial vascular response to ET-1 was biphasic consisting of an initial increase in flow (vasodilatation) of short duration followed by a prolonged reduction in flow (vasoconstriction). The hepatic portal circuit was perfused at a constant flow with blood derived from the mesenteric circuit. Hepatic portal inflow pressure was continuously recorded. ET-1 injected intraportally increased the portal perfusion pressure indicating an increase in portal inflow resistance. This portal vasoconstrictor response to ET-1 was of much longer duration than that previously observed with other vasoactive agents in this vascular territory.
Withrington
P G
PG
Department of Pharmacology, St Bartholomew's Hospital Medical College, London, England.
de Nucci
G
G
Vane
J R
JR
D000818:Animals; D004285:Dogs; D016232:Endothelins; D006499:Hepatic Artery; D066298:In Vitro Techniques; D007269:Injections, Intra-Arterial; D007545:Isoproterenol / Q000494:pharmacology; D008102:Liver Circulation / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D010455:Peptides / Q000008:administration & dosage / Q000494:pharmacology*; D010477:Perfusion; D011169:Portal Vein; D014661:Vasoconstriction / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects*
D016232:Endothelins; D010455:Peptides; D007545:Isoproterenol; D009638:Norepinephrine