EFFECTS OF CD-832, A DIHYDROPYRIDINE DERIVATIVE WITH A NITRATE ESTER MOIETY, ON RABBIT FEMORAL-ARTERY AND VEIN

We investigated the effects of CD-832 ((4R)-(-)-2-(nicotinoyl-amino)et hyl 3-nitroxypropyl 1,4-dihydro-2,6-dimethyl-4,3-nitrophenyl, 3,5-pyri dine dicarboxylate), a dihydropyridine derivative with a nitrate ester moiety, on contractile responses in rabbit femoral arteries and veins . CD-832 (10(-8) to 10(-6) M) and nifedipine inhibited the 64 mM KCl-i nduced and 10(-6) M norepinephrine-induced contractions of rabbit femo ral arteries, while nitro compounds had no effect on the contractions. CD-832 (10(-8) to 10(-6) M) and nitro compounds inhibited the 10(-6) M norepinephrine-induced contractions in rabbit femoral veins, while o ther Ca2+ channel antagonists had little effect. The inhibitory effect s of CD-832 (10(-7) M) on norepinephrine-induced contractions were ant agonized by treatment with methylene blue (10(-5) M). These results in dicate that CD-832 potently relaxes venous smooth muscle, and that it may be a useful agent for the treatment of angina pectoris.