Vasodilator profile of a new 1,4-dihydropyridine derivative, 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-[2-(N-benzyl-N-methylamino)]-ethyl ester 5-methyl ester hydrochloride (YC-93).

: A new 1,4-dihydropyridine derivative, 2,6-dimethyl-4-(3-nitrophenyl)-4,4-dihydropyridine-3,5-dicarboxylic acid 3-[2-(N-benzyl-N-methylamino)]-ethyl ester 5-methyl ester hydrochloride (YC-93), when i.v. injected into anesthetized dogs, exhibited not only a greated vasodilation in both cerebral and coronary than in femoral vessels, but also about 100 to 300 times higher potency as well as longer durability than any of reference drugs such as isoxsupurine, papaverine and cinnarizine. YC-93 was also effective in vasodilation by i.m. and i.d. administration. When administered into vertebral and coronary arteries, YC-93 caused vasodilation at the doses that did not affect systemic blood pressure. YC-93 did not potentiate the vasodilator effect of adenosine, and vasodilation by YC-93 was influenced by neither propranolol, atropine, diphenhydramine nor aminophylline. Acute toxicity (LD50) of YC-93 was almost the same as that of papaverine in mice and rats. Thus, YC-93 is a potent bu low-toxic vasodilator agent acting preferentially and perhaps directly on cerebral and coronary vascular beds and is well absorbed from gastrointestinal tract into blood stream.