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.