Selective and competitive urotensin-II (UT) receptor antagonist (pKB = 8.3). Blocks hU-II induced contractions in thoracic aorta ex vivo. Exhibits no effect on noradrenaline or endothelin 1-induced contraction or on acetylcholine-induced relaxation. Behav
ABT-546 (A-216546) is a potent, highly selective, and active endothelin ETA receptor antagonist with a Ki of 0.46 nM for [125I]endothelin-1 binding to cloned human endothelin ETA.
A-192621 is a potent, nonpeptide, orally active and selective endothelin B (ETB) receptor antagonist with an IC50 of 4.5 nM and a Ki of 8.8 nM. A-192621 promotes apoptosis in PASMCs and it also causes elevation of arterial blood pressure and an elevation