蛇床子素对家兔主动脉条的钙拮抗作用

蛇床子素30μmol·L~(-1)及100μmol·L~(-1)使NE、CaCl_2和高K~+除极化所致的家兔主动脉条收缩量—效曲线右移,最大反应降低.表明蛇床子素有松弛血管平滑肌作用,并与Ca~(2+)呈非竞争性拮抗作用.和阻滞α受体或激动β受体无关;选择性作用于电位依赖性Ca~(2+)通道,抑制细胞外Ca~(2+)内流;在100μmol·L~(-1)时,明显减弱NE诱导的依赖细胞内Ca~(2+)收缩。证明蛇床子素松弛血管平滑肌作用可能与其Ca~(2+)拮抗作用有关。

Calcium -antagonistic effects of osthole on isolated rabbit aortic strips

It was reported that Os-thole(Ost) was isolated from the fruits of Cnidium monnieri(L. ) Cusson, possesses anti - arrhythmic action and depressed the aortic pressure action in animal studies. Its calcium -antagonistic effects were studied on the isolated rabbit aortic strips. Ost shifted the dose response curves for NE, CaCl2 and KC1 nonparallelly to the right, and depressed their maximal response; pD2' value is 3. 16, 4. 28 and 4. 39 respectively. It produced neither β- a-drenoceptic stimulating nor α - adreno-ceptic blocking effects. At the concentration of 100 μmol · L-1, Ost significantly inhibited the intra cellular Ca2+ dependent component of NE - induced contraction of the aortic strips, however, it didn't in- hibit the extra cellular Ca2+ dependent component of NE - induced contraction of the aortic strips, These results indicated that Ost produced relaxation on vascular smooth muscle might result from its antagonistic effect to Ca2+ and mainly blocked calcium influx through PDC, and the mode of its anta -gonism is similar to that of verapamil.