Rec 15/2615 is an antagonist of α1B-adrenergic receptors (α1B-ARs; Ki = 0.45 nM for the recombinant human receptor).1 It selectively inhibits α1B-ARs over α1A-, α1D-, and α1L-ARs (Kis = 7.59, 10.23, and 49 nM, respectively). Rec 15/2615 inhibits norepinephrine-induced contractions of isolated rabbit prostate and urethral strips (Kis = 100 and 316.2 nM, respectively), as well as reduces norepinephrine-induced contractions of chloroethylclonidine-precontracted isolated rabbit aortic rings (Ki = 50 nM).2 It decreases diastolic blood pressure (ED25 = 183 μg/kg, i.v.) and increases intracavernous pressure in anesthetized dogs when administered intracavernously at doses ranging from 30 and 1,000 μg/kg.1,2

|1. Sironi, G., Colombo, D., Poggesi, E., et al. Effects of intracavernous administration of selective antagonists of α1-adrenoceptor subtypes on erection in anesthetized rats and dogs. J. Pharmacol. Exp. Ther. 292(3), 974-981 (2000).|2. Testa, R., Guarneri, L., Angelico, P., et al. Pharmacological characterization of the uroselective alpha-1 antagonist Rec 15/2739 (SB 216469): Role of the alpha-1L adrenoceptor in tissue selectivity, part II. J. Pharmacol. Exp. Ther. 281(3), 1284-1293 (1997).