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Updated: Oct 9, 2026

In vitro Measurements of Tracheal Constriction Using Mice
Published on: June 25, 2012
Pharmacological evidence for distinct endothelin receptors in guinea-pig bronchus and aorta
1Department of Pharmacology, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406-0939.
Abstract:
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.
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