黄芪甲苷对正常大鼠离体血管功能的影响

目的观察黄芪甲苷对血管功能的影响并探讨其作用机制。方法采用大鼠离体主动脉环灌流模型,观察黄芪甲苷对血管环收缩和舒张功能的影响。结果黄芪甲苷能够浓度依赖性舒张血管。一氧化氮合酶抑制剂、鸟苷酸环化酶及环加氧酶抑制剂可抑制黄芪甲苷诱导的血管舒张作用。黄芪甲苷能够抑制苯肾上腺、KC l和CaC l2引起的血管收缩。结论黄芪甲苷具有内皮依赖性的舒张血管作用,此作用主要通过NO-cGMP途径发挥作用。黄芪甲苷抑制血管收缩主要通过拮抗外钙内流实现。

Effect of astragaloside Ⅳ on contraction and relaxation in isolated rat aortic rings

Aim To study the effect and investigate the underlying mechanism of astragaloside Ⅳ on contraction and relaxation in isolated rat aortic rings.Methods The relaxation effect of astragaloside Ⅳ(1～100 mg·L~(-1))on phenylephrine-preconstricted aorta ring was recorded.The effect of astragaloside Ⅳ on the contraction induced by cumulative phenylephrine,KCl or CaCl_2,was recorded respectively.Results Astragaloside Ⅳ dilated aortic vessels in a dose-dependent manner,which was partly inhibited by preincubation with non-selective nitric oxide synthase inhibitor,guanylyl cyclase inhibitor and cyclooxygenases inhibitor indomethacin.Astragaloside IV could also antagonize phenylephrine-,KCl-and CaCl_2-induced vessel contraction.Conclusion Astragaloside IV dilated aortic vessels partially though endothelium-dependent NO pathway and inhibited vessel contraction via interfering Ca~(2+) influx.