1998 年 21 巻 11 号 p. 1163-1168
Vasoactive effects of cimicifugic acids A-E, fukinolic acid and fukiic acid isolated from Cimicifuga plants were investigated using rat aortic strips. Cimicifugic acid D and fukinolic acid at 3×10-4M caused a sustained, slowly developing relaxation of aortic strips precontracted with norepinephrine (NE) in preparations with or without endothelium. Cimicifugic acid C inversely caused a weak contraction. Cimicifugic acids A, B and E and fukiic acid showed no vasoactivity at 3×10-4 M. Cimicifugic acids A-E and fukinolic acid are esters between cinnamic acids and the hydroxyl group of benzyltartaric acids. For the manifestation of vasoactivity in the rat aorta, it is concluded that in the cinnamic acid moiethy, a caffeoyl group might be necessary for the relaxaion activity, and the p-coumaroyl group causes contraction.Concentration response curves for the Ca2+-induced contracture of depolarized aortic strips with isotonic high K+ were not affected by cimicifugic acid D or fukinolic acid. The Ca2+-induced contraction of aortic strips, preincubated with 10-6 M NE in the prsence of 10-6 M nicardipine and 0.01 mM EGTA in Ca2+-free solution, were inhibited by cimicifugic acid D and fukinolic acid. These results indicated that the inhibition by cimicifugic acid D and fukinolic acid of the NE-induced contraction of rat aorta are attributable to the suppression of Ca2+ influx from the extracellular space enhanced by NE.
