苦碟子水提取液对大鼠离体胸主动脉环的舒张作用

目的研究苦碟子的内皮依赖性血管舒张作用,并探讨其可能机制。方法采用大鼠离体主动脉环灌流模型,观察累积浓度苦碟子对基础状态、去氧肾上腺素(PE)和氯化钾(KCl)预收缩的内皮完整血管环和去内皮血管环的舒张作用。结果苦碟子水提取液(苦碟子注射液,相当于含苦碟子原材料0.01～10g.L-1)对基础状态的内皮完整血管环和去内皮血管环的张力无影响。对PE预收缩的内皮完整血管环,苦碟子在累积浓度0.03～10g.L-1呈浓度依赖性舒张作用,分别用一氧化氮合酶抑制剂左旋硝基精氨酸甲酯(0.1mmol.L-1)和鸟苷酸环化酶抑制剂亚甲蓝(10μmol.L-1)预处理,此作用被抑制,用环氧合酶抑制剂吲哚美辛(10μmol.L-1)预处理亦被抑制。对KCl预收缩的内皮完整血管环和对PE或KCl预收缩的去内皮血管环,苦碟子在累积浓度0.01～10g.L-1无明显舒缩作用。结论苦碟子(0.03～10g.L-1)对主动脉具有内皮依赖性舒张作用。该作用可能是通过血管内皮细胞一氧化氮-鸟苷酸环化酶途径和血管内皮细胞环氧合酶途径介导的。

Vasodilation effect of water extract from Ixeris sonchifolia (Bge.)Hance in rat thoracic aortic rings in vitro

AIM To investigate the endothelium-dependent vasodilation effect of the water extract from Ixeris sonchifolia(Bge.) Hance (WEISH) in rat thoracic aorta and its possible mechanism. METHODS WEISH 0.01-10 g·L^-1 (injection, corresponding to raw material) was cumulatively added into organ bath. Isometrictension of endothelium-intact or endothelium-denuded thoracic aortic rings in basal tension, preconstricted by phenylephrine (PE) and potassium chloride (KCl), respectively, was recorded. RESULTS Cumulative administration of WEISH 0.01-10 g·L^-1 did not affect the vasomotion of aortic rings with endothelium or without endothelium in basal tension. Exposure of intact endothelium rings preconstricted by PE to WEISH at the concentrations of 0.03-10 g·L^-1 induced a significant concentration-dependent relaxation, which was inhibited by preincubation with N^ω-nitro-L-arginine methyl ester, methylene blue and indometacin, respectively. Exposure of intact endothelium rings preconstricted by KCl and endothelium-denuded rings preconstricted by PE or KCl to WEISH at the concentrations of 0.03-10 g·L^-1 did not affect the vasomotion. CONCLUSION WEISH 0.03-10 g·L^-1 has endothelium-dependent relaxation effect on aortic rings. This effect may be mediated by the nitric oxide-guanylyl cyclase pathway and cyclooxygenase pathway.