Effect of endothelin-1 on regional vascular resistances in the pig.
The actions of endothelin-1 (ET-1) on vascular resistances were investigated and characterized in anesthetized pigs in vivo. Intravenously administered ET-1 (2-400 pmol/kg) caused dose-dependent increases in mean arterial blood pressure accompanied by a reduction in heart rate. ET-1 also increased renal, coronary, femoral, and bronchial vascular resistances. The kidney was about 10 times more sensitive to ET-1 than the other regions. The ET-1-induced vasoconstriction in the kidney was attenuated by nifedipine (100 micrograms/kg). The responses to ET-1 in the femoral and bronchial vascular beds were biphasic with an initial decrease followed by an increase in vascular resistance at high doses. It is concluded that ET-1 causes dose-dependent vasoconstriction in several vascular beds in vivo with the most pronounced effects in the renal circulation.
Pernow
J
J
Department of Pharmacology, Karolinska Institutet, Stockholm, Sweden.
Franco-Cereceda
A
A
Matran
R
R
Lundberg
J M
JM
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D016232:Endothelins; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D007275:Injections, Intravenous; D008297:Male; D009543:Nifedipine / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D012039:Regional Blood Flow / Q000187:drug effects*; D013552:Swine; D014655:Vascular Resistance / Q000187:drug effects*
D016232:Endothelins; D010455:Peptides; D009543:Nifedipine