Pharmacological evidence for distinct endothelin receptors in guinea-pig bronchus and aorta.
The ETA receptor antagonist, BQ-123 (1 microM) potently antagonized endothelin-1 (ET-1) concentration-response curves in guinea-pig aorta (pKB = 7.1). However, 10 microM BQ-123 was without effect on ET-1-induced contractions in guinea-pig bronchus. The ETB-selective agonist, sarafotoxin S6c did not contract the aorta but was a potent and effective contractile agonist in the bronchus. BQ-123 (10 microM) was without effect on sarafotoxin S6c-induced contractions in the bronchus. These data provide evidence for distinct endothelin receptors in guinea-pig aorta and bronchus, which appear to be predominantly of the ETA and non-ETA, perhaps ETB, subtypes, respectively.
Hay
D W
DW
Department of Pharmacology, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406-0939.
D000818:Animals; D001011:Aorta / Q000737:chemistry* / Q000187:drug effects; D001980:Bronchi / Q000737:chemistry* / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D016232:Endothelins / Q000378:metabolism*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D010456:Peptides, Cyclic / Q000494:pharmacology; D017466:Receptors, Endothelin / Q000032:analysis* / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014757:Viper Venoms / Q000494:pharmacology
D016232:Endothelins; D010456:Peptides, Cyclic; D017466:Receptors, Endothelin; D014662:Vasoconstrictor Agents; D014757:Viper Venoms; C057354:sarafotoxins s6; C072247:cyclo(Trp-Asp-Pro-Val-Leu)