In:
British Journal of Pharmacology, Wiley, Vol. 113, No. 2 ( 1994-10), p. 336-338
Abstract:
In the rabbit isolated pulmonary artery, neither the ET A receptor antagonist, BQ‐123 (10 μ m ), nor the ET B receptor antagonist, BQ‐788 (10 μ m ), inhibited the contractions induced by 1 n m endothelin‐1 (ET‐1). However, the combination of BQ‐123 and BQ‐788 completely inhibited the ET‐1‐induced contraction. In contrast, the ET B ‐selective agonist, sarafotoxin S6c (1 n m )‐induced contraction was completely inhibited by BQ‐788 but not by BQ‐123. In receptor binding assays, [ 125 I]‐ET‐1 specific binding to pulmonary arterial membranes was inhibited by BQ‐123 (1 μ m ) by approximately 20% and additive treatment with BQ‐788 (1 μ m ) completely inhibited the BQ‐123‐resistant component of [ 125 I]‐ET‐1 specific binding. The present study demonstrates synergistic inhibition by BQ‐123 and BQ‐788 of ET‐1‐induced contraction of the rabbit pulmonary artery and the coexistence of ET A and ET B receptors, suggesting that the activation of either only ET A or only ET B receptors may be sufficient to cause complete vasoconstriction. Therefore, blockade of both receptor subtypes would be necessary for the inhibition of some ET A /ET B composite types of responses.
Type of Medium:
Online Resource
ISSN:
0007-1188
,
1476-5381
DOI:
10.1111/bph.1994.113.issue-2
DOI:
10.1111/j.1476-5381.1994.tb16901.x
Language:
English
Publisher:
Wiley
Publication Date:
1994
detail.hit.zdb_id:
2029728-2
SSG:
15,3
