Pharmacological Characterization of Vasorelaxant Effects of BMS-180448, a Novel Cardioselective ATP-Sensitive Potassium Channel Opener, in Rat Aorta

This study was designed to characterize vasorelaxant effects of BMS-180448 ((3S-trans)-N-(4-chlorophenyl)-N'-cyano-N''-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-4-yl)), a prototype cardioselective ATP-sensitive potassium channel opener, in rat aorta. BMS-180448 relaxed phenylephrine-precontracted endothelium-intact aortic rings (IC50: 0.97 ± 0.29 μM), the effect being significantly attenuated by removal of functional endothelium (IC50: 1.95 ± 0.23 μM) and pretreatment with NG-nitro- L -arginine methyl ester ( L -NAME) or methylene blue. BMS-180448 completely relaxed endothelium-denuded aorta contracted with phorbol 12,13-dibutyrate, PGF2α, and U46619 with a significantly greater potency (IC50: 0.069 ± 0.002, 0.055 ± 0.002, and 0.068 ± 0.008 μM, respectively, P