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Dose‐ and time‐dependency of the dilator effects of the endothelin antagonist, BQ‐123, in the human forearm
Author(s) -
Berrazueta José R.,
Bhagat Kiran,
Vallance Patrick,
MacAllister Raymond J.
Publication year - 1997
Publication title -
british journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.216
H-Index - 146
eISSN - 1365-2125
pISSN - 0306-5251
DOI - 10.1046/j.1365-2125.1997.t01-1-00631.x
Subject(s) - dilator , forearm , endothelin receptor , medicine , plethysmograph , endothelin 1 , vasoconstriction , endothelin receptor antagonist , constriction , endocrinology , antagonist , blood flow , anesthesia , receptor , anatomy
Aims Endothelin‐1 is a potent endogenous vasoconstrictor that acts on the endothelin A (ET A ) receptor. The dose‐response and time‐course of the dilator effect of the ET A receptor antagonist, BQ‐123, was investigated in the forearm of healthy volunteers. Methods Forearm blood flow was measured using mercury‐in rubber strain gauge venous occlusion plethysmography. Results Following intra‐arterial infusion of BQ‐123 (50 nmol min −1 ) for 5 min, forearm blood flow increased by approximately 60% over the next 60 minutes; lower doses were without significant effect. The degree of dilatation was similar to that observed in previous studies using 20‐fold larger doses. Conclusions This study confirms that basal endothelin‐1 has a role in the physiological regulation of vascular tone. It is possible that at low doses, BQ‐123 might be a more sensitive pharmacological tool for the detection of abnormal endothelin‐1 mediated constriction.