PMID: 8587383Jan 1, 1995Paper

Are there different ETB receptors mediating constriction and relaxation?

Journal of Cardiovascular Pharmacology
M Clozel, G A Gray

Abstract

Because certain antagonists of endothelin (ET) ETB receptors (such as the mixed ETA+ETB antagonist PD 142893 or the selective ETB receptor antagonist BQ-788) were shown to antagonize the ETB-mediated dilatation to ET-1 but not the ETB-mediated constriction to ET-1, the existence of two subtypes of to ET-1, the existence of two subtypes of ETB receptors was suggested. The goal of the present study was to further explore this absence of functional antagonism of ETB-mediated constriction by so-called ETB receptor antagonists. In rat tracheal rings denuded of epithelium, Ro 46-8443, a selective ETB receptor antagonist, did not shift the concentration-response curve of ET-1 but antagonized sarafotoxin S6c-induced contractions. However, the ET-1-mediated contractions could be attributed to ETB receptor activation, because BQ-123 had no inhibitory effect except at high doses of ET-1. Preincubation of tracheal rings with BQ-123 (10(-5) M) to block ETA receptors revealed an antagonist effect of Ro 46-8443 on contractions induced by ET-1. By analogy with these pharmacologic experiments, desensitization of ETB receptors by preincubation with sarafotoxin S6c did not modify contractile responses to ET-1 except when the tracheal rings were e...Continue Reading

Citations

Mar 24, 2007·Langenbeck's Archives of Surgery·Reto WettsteinYves Harder
Oct 27, 1998·European Journal of Pharmacology·M ZuccarelloR M Rapoport
Sep 19, 2012·Journal of Cardiovascular Pharmacology·Robert M Rapoport, Mario Zuccarello
Mar 23, 2011·Pharmacological Research : the Official Journal of the Italian Pharmacological Society·Al-karim Khimji, Don C Rockey
Aug 3, 2007·Experimental Eye Research·Rita RosenthalHagen Thieme
Nov 9, 2010·British Journal of Pharmacology·Rita Rosenthal, Michael Fromm
Aug 19, 2014·British Journal of Pharmacology·J J Maguire, A P Davenport
Sep 16, 2017·Terapevticheskiĭ arkhiv·Z S ValievaI E Chazova

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