Identification of a Dihydropyridine as a Potent α_1aAdrenoceptor-Selective Antagonist That Inhibits Phenylephrine-Induced Contraction of the Human Prostate

A number of novel dihydropyridine derivatives based upon 1,4-dihydro-3-(methoxycarbonyl)-2,6-dimethyl-4-(4-nitrophenyl)-5-((3-(4, diphenylpiperdin-1-yl)propyl)aminocarbonyl)pyridine (4) have been synthesized and tested at cloned human a adrenoceptors as well as the rat L-type calcium channel. Within this compound series, 5-(aminocarbonyl)-1,4-dihydro-2,6-dimethyl-4-(4-nitrophenyl)- 3-((3-(4,4-diphenylpiperidin-1-yl)propyl)aminocarbonyl)pyridine (19) displayed good binding affinity and selectivity for the alpha(1a) adrenoceptor (pK(i) = 8.73) and potently inhibited (pA(2) = 9.23) phenylephrine-induced contraction of the human prostate.