PT  - JOURNAL ARTICLE
AU  - Webb, M L
AU  - Bird, J E
AU  - Liu, E C
AU  - Rose, P M
AU  - Serafino, R
AU  - Stein, P D
AU  - Moreland, S
TI  - BMS-182874 is a selective, nonpeptide endothelin ETA receptor antagonist.
DP  - 1995 Mar 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 1124--1134
VI  - 272
IP  - 3
4099  - http://jpet.aspetjournals.org/content/272/3/1124.short
4100  - http://jpet.aspetjournals.org/content/272/3/1124.full
SO  - J Pharmacol Exp Ther1995 Mar 01; 272
AB  - BMS-182874 [5-(dimethylamino)-N-(3,4-dimethyl-5-isoxazolyl)-1-naphthalene sulfonamide] is a recently discovered, low molecular weight, nonpeptide endothelin (ET) receptor antagonist. BMS-182874 competitively inhibited the binding of [125I]ET-1 to ETA receptors in rat vascular smooth muscle A10 (VSM-A10) cell membranes (Ki = 61 nM) and in CHO cells stably expressing the human ETA receptor (Ki = 48 nM), but was a weak inhibitor at ETB receptors (Ki > 50 microM) and non-ET receptors. BMS-182874 inhibited ET-1-stimulated inositol phosphate accumulation (KB = 75 nM) and calcium mobilization (KB = 140 nM) without suppressing the maximal responses in VSM-A10 cells. BMS-182874 was a competitive antagonist of force development elicited by stimulation of ETA, but not other, receptors in isolated blood vessels such as the rabbit carotid artery (KB = 520 nM). The apparent discrepancy between efficacy in cell and tissue models was likely related to the high degree of protein binding exhibited by BMS-182874. When administered either orally (ED50 = 30 mumol/kg) or intravenously (ED50 = 24 mumol/kg) to conscious, normotensive rats, BMS-182874 blunted the pressor response to exogenous ET-1. These data demonstrate that BMS-182874 is a competitive, selective and orally active ETA receptor antagonist that will be useful in understanding the role of ET in normal and disease states.