AH 11110 hydrochloride is a subtype-selective ligand for the α1B-adrenoceptor (α1B-AR). The pKi values for binding to rat fibroblast cell membranes expressing α1B (hamster), α1A (bovine) and α1D (rat) are 7.1, 5.59, and 5.68 respectively. AH 11110 hydrochloride appears to be non-selective between α1 subtypes and α2 receptors in smooth muscle preparations.