Cardiac output effects of endothelin-1, -2 and -3 and sarafotoxin S6b in conscious rats.
Conscious, Long-Evans rats, chronically-instrumented for the direct measurement of intra-arterial and central venous pressures and ascending aortic blood flow (i.e. cardiac output), were given bolus, intravenous doses (4 and 40 pmol) of endothelin-1, -2, or -3 or sarafotoxin S6b in random order. The lower dose of endothelin-1 and -3 and sarafotoxin S6b caused a significant increase in cardiac output. The higher bolus dose of the same three peptides caused initial hypotension and increases in cardiac output, stroke volume and total peripheral conductance. Endothelin-2 did not have these initial effects in all animals. Subsequently, all peptides increased mean arterial blood pressure and decreased cardiac output and total peripheral conductance. Overall the effects of endothelin-1 and sarafotoxin S6b were very similar, consistent with them acting at the same site.
Department of Physiology and Pharmacology, Queen's Medical Centre, Nottingham, U.K.
S M
SM
Gardiner
A M
AM
Compton
P A
PA
Kemp
T
T
Bennett
D000818:Animals; D001013:Aorta, Thoracic / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D016232:Endothelins; D004730:Endothelium, Vascular / Q000378:metabolism; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D010455:Peptides / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012039:Regional Blood Flow; D013318:Stroke Volume / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014757:Viper Venoms / Q000494:pharmacology*
D016232:Endothelins; D010455:Peptides; D014662:Vasoconstrictor Agents; D014757:Viper Venoms; C057354:sarafotoxins s6