Antihypertensive effect of NKY-722, a new water-soluble 1,4-dihydropyridine derivative, on conscious spontaneously hypertensive rats.

3-(4-Allyl-1-piperazinyl)-2,2-dimethylpropyl methyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridine dicarboxylate dihydrochloride (NKY-722) produced a dose-dependent antihypertensive effect in conscious spontaneously hypertensive rats (SHR). In this respect NKY-722 was more potent and longer-acting than nicardipine. In canine isolated mesenteric arteries, exposed to a Ca2+-free medium containing high K+, NKY-722 inhibited Ca2+-induced contraction in concentration-dependent manner, suggesting the calcium antagonism as the mechanism of action.