标题：In Vitro and ex Vivo Ca-Antagonistic Effect of 2-Methoxyethyl (E)-3-phenyl-2-propen-1-yl (±)-1, 4-dihydro-2, 6-dimethyl-4-(3-nitrophenyl) pyridine-3, 5-dicarboxylate (FRC-8653), a New Dihydropyridine Derivative
摘要：The characteristics of calcium antagonism and vascular effect of 2-methoxyethyl (E)-3-phenyl-2-propen-1-yl (±)-1, 4-dihydro-2, 6-dimethyl-4-(3-nitrophenyl) pyridine-3, 5-dicarboxylate (FRC-8653) were investigated. FRC-8653 inhibited an increase in intracellular free calcium concentration during membrane depolarization in PC12 cells. FRC-8653 also inhibited the specific binding of 3H-nitrendipine to cardiac membranes, in a similar manner to nifedipine and nicardipine. FRC-8653 inhibited KCl- and CaCl2-induced contractions in isolated rabbit aorta, but failed to affect norepinephrine-induced contraction. The vasorelaxing effect of FRC-8653 in rabbit aorta developed more slowly than those of nifedipine and nicardipine. In ex vivo experiment, the inhibitory effect of orally administered FRC-8653 against KCl-contraction in rat aorta lasted longer than that of nifedipine. These findings suggest that FRC-8653 dilates blood vessels by blocking calcium influx via dihydropyridine-sensitive, voltage-dependent calcium channels and that the vascular effects are slow in development and long in duration.
