Relaxing effect of atrial natriuretic factor on endothelin-precontracted vascular strips.
Endothelin (ET), a peptide recently isolated from the supernatant of cultured porcine aortic endothelial cells, is a potent vasoconstrictor. On the other hand, atrial natriuretic factor (ANF) is a powerful vasorelaxant found in cardiocytes. Its effect was investigated in ET-precontracted rabbit vascular strips. ANF-induced a dose-dependent relaxation of maximally-precontracted mesenteric, renal and aortic strips. Mesenteric artery strips were more sensitive to ANF than either renal or aortic strips. The relaxant effect of ANF on ET-precontracted arteries was more potent than that of other vasorelaxant agents, such as isoproterenol and sodium nitroprusside. Renal and aortic arteries were more sensitive to the vasoconstrictor effect of ET than mesenteric strips. From these results, we conclude that ANF may play a role as a physiological antagonist of ET. The different sensitivity of vascular segments to ET could be due to varying vascular ET receptor densities.
Bonhomme
M C
MC
Laboratory of Experimental Hypertension and Vasoactive Peptides, Clinical Research Institute of Montreal, Quebec, Canada.
Cantin
M
M
Garcia
R
R
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D016232:Endothelins; D004730:Endothelium, Vascular / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D010455:Peptides / Q000494:pharmacology*; D011817:Rabbits; D014661:Vasoconstriction / Q000187:drug effects*
D016232:Endothelins; D010455:Peptides; D009320:Atrial Natriuretic Factor