Silodosin-d4 is intended for use as an internal standard for the quantification of silodosin by GC- or LC-MS. Silodosin is an α1A-adrenergic receptor (α1A-AR) antagonist (Ki = 0.036 nM).1 It is 583- and 56-fold selective for α1A- over α1B- and α1D-ARs, respectively. Silodosin inhibits phenylephrine-induced contraction of isolated rabbit prostate (pA2 = 10.05) more potently than rabbit or rat aorta (pA2s = 9.36 and 8.13, respectively).2 It inhibits norepinephrine-induced contraction of isolated human prostate tissue when used at concentrations ranging from 0.3 to 10 nM.1 Silodosin (0.01-1,000 µg/kg) inhibits phenylephrine-induced increases in intraurethral pressure in rats.3 Formulations containing silodosin have been used in the treatment of benign prostatic hyperplasia.
1.Moriyama, N., Akiyama, K., Murata, S., et al.KMD-3213, a novel α1A-adrenoceptor antagonist, potently inhibits the functional α1-adrenoceptor in human prostateEur. J. Pharmacol.331(1)39-42(1997) 2.Yamagishi, R., Akiyama, K., Nakamura, S., et al.Effect of JMD-3213, an α1a-adrenoceptor-selective antagonist, on the contractions of rabbit prostate and rabbit and rat aortaEur. J. Pharm.315(1)73-79(1996) 3.Akiyama, K., Hora, M., Tatemichi, S., et al.KMD-3213, a uroselective and long-acting α1a-adrenoceptor antagonist, tested in a novel rat modelJ. Pharmacol. Exp. Ther.291(1)81-91(1999)