黄芪的内皮依赖性血管舒缩作用及其机制  

Astragalus membranaceus induced endothelium-depende nt vasomotor effect and its mechanism in rat thoracic aortas

作　　者：张必祺[1] 孙坚[1] 胡申江[1] 单绮娴[2] 夏强[2] 

机构地区：[1]浙江大学医学院附属第一医院心内科,浙江杭州310003 [2]浙江大学医学院生理学教研室,浙江杭州310031

出　　处：《中国药理学与毒理学杂志》2005年第1期44-48,共5页Chinese Journal of Pharmacology and Toxicology

基　　金：浙江省中医药管理局基金资助项目(2 0 0 0C5 4 ) ;浙江省中医药管理局基金资助项目 (2 0 0 3C0 78);浙江省人事厅留学回国人员基金资助项目〔浙人专 2 0 0 1(2 75 )〕~~

摘　　要：目的　黄芪有一定的治疗高血压作用 ,本研究观察其对大鼠离体胸主动脉环舒缩的影响 ,并探讨其可能机制。方法　采用大鼠离体主动脉环灌流模型 ,观察累积浓度黄芪 (0 .0 1～ 10 0g·L- 1)对基础状态、KCl预收缩和去氧肾上腺素 (PE)预收缩的血管环的作用。结果　黄芪 (0 .0 1～ 10 0g·L- 1)对基础状态或KCl预收缩的内皮完整血管环张力无影响。对PE预收缩的内皮完整血管环 ,黄芪在低浓度 (0 .0 1～ 3.0g·L- 1)时呈浓度依赖性舒张作用 ,此作用可被一氧化氮合酶抑制剂左旋硝基精氨酸甲酯(0 .1mmol·L- 1)或鸟苷酸环化酶抑制剂亚甲蓝 (10μmol·L- 1)预处理所抑制 ;而在高浓度 (10～ 10 0g·L- 1)时呈短暂的收缩作用 ,可被内皮素转换酶抑制剂磷阿米酮 (5 μmol·L- 1)预处理所抑制。黄芪对PE预收缩的去除内皮血管环仅呈微弱的浓度依赖性舒张作用。结论　黄芪对主动脉具有内皮依赖性舒缩双相作用。其舒张机制可能为激活血管内皮细胞一氧化氮 鸟苷酸环化酶途径 ;而其收缩机制可能为促进血管内皮合成内皮素。AIM To study why Astragalus membranaceus (AM) c an be used as a hypotensive, the vasomotor effect of AM on rat thoracic aorta ring s and the underlying mechanism were investigated. METHODS AM 0.01- 100 g·L -1 was cumulatively added into organ bath. Isometric tension of e ndothelium -intact or denuded thoracic aorta rings in basal tension, preconstricted by KCl or phenylephrine (PE), respectively, was recorded. RESULTS Cumulat ive administration of AM 0.01-100 g·L -1 did not affect the vasomotion of aortic rings with endothelium either in basal tension or preconstricted by KC l. Exposure of endothelium intact rings precontricted by PE to AM at low concent ration (0.1-3.0 g·L -1) induced a significant concentration dependent rel axation, which was inhibited by preincubation with Nω-nitro-L-arginine methyl ester or methylthioninium chloride. But at the high concentration (10-100 g·L -1), AM transiently potentiated the PE evok ed contr action that can be reversed by phosphoramidone. Moreover, a weak vasorelaxant re sponse to AM in endothelium-denuded rings precontracted by PE was observed. CONCLUSION AM has endothelium-dependent diphasic effects of relaxat ion and contraction on aorta rings. The effect of relaxation may be mediated by the NO-guanylyl cyclase pathway, while the contration may be related to end othelin release.

关 键 词：黄芪 主动脉 胸 血管舒张 血管收缩 

分 类 号：R285[医药卫生—中药学]