黄酮类化合物WX-02对兔离体血管环的舒张作用

Relaxingeffect of an flavonoid WX-02 on isolated vascular rings of rabbits

目的探讨黄酮类化合物WX-02对兔离体血管环的舒张作用及其作用机制。方法采用兔离体血管环灌流方法，记录WX-02对去甲肾上腺素（norepinephrine，NE）、氯化钾（KCl）收缩的血管环的舒张作用；观察WX-02的舒张作用与内皮的关系；比较WX-02（0．1、0．3mmol·L-1）孵育后CaCI，累积收缩量效曲线的变化及由NE引起的依赖于细胞内钙和外钙收缩反应的变化。结果浓度为0．03～1．0mmol·L-1 WX-02能舒张由致痉剂高钾、去甲肾上腺素引起的收缩；内皮不影响WX-02的舒张作用；浓度为0．1、0．3mmol·L-1 WX-02均能使CaCl2累积收缩量效曲线右移，低浓度的WX-02可能抑制细胞内钙外流，而高浓度的WX-02抑制细胞内钙外流和外钙内流。结论WX-02能够浓度依赖性的舒张血管平滑肌，其作用机制与内皮无关，与阻断不同的钙通道有关。

Objective To study the relaxing effect and its mechanism of an flavonoid WX-02 on isolated vas- cular tings of rabbits. Methods The isolated tings were perfused and the effect of WX-02 on the preparations pre-contracted with NE or KC1 was recorded. The effects of WX-02 on endothelium-intact （ ＋ EC） and en- dothelium-denuded（-EC） thoracic aortic tings were observed and the influence on vasoconstrictor effect of CaC1z and NE after incubation with WX-02 （0. 1,0. 3 mmol- L - 1 ） was compared. Results WX-02 （0. 03- 1.0 mmol.L-l） had a relaxing effect on isolated aorta tings of rabbits pre-contracted with NE or KC1; the relaxing effect of WX-02 was not affected by endothelial; incubation of WX-02 （0. 1 mmol. L-I, 0. 3 mmol.L-~）shifted the concentration-response curves of CaC12 to the tight. The outflow of intracellular calcium might be inhibited by low concentration of WX-02 （ 0. 1 mmol. L- 1 ）, while outflow of intracellular calcium and influx of extmcellular calcium might be inhibited by high concentration of WX-02 （0. 3 mmol .L -1 ）. Conclusions WX-02 has a concentration-dependent relaxing effect on the vascular smooth muscle; the mechanism is not relevant to endothelial, but associated with the inhibition of different Ca2 ＋ channels.