中文摘要：

目的 研究植物雌激素大豆黄酮（daidzein，Dai）的舒张血管效应与血管内皮M受体，细胞内、外钙的关系。方法 采用家兔离体主动脉环进行等长张力实验。结果 Dai（3～100μmol·L^-1）对苯肾上腺素（phenylephrine，PHE）依内Ca^2＋性收缩和依外Ca^2＋性收缩均具有显著的抑制作用；Dai（10～100μmol·L^-1）可使KCl的量效曲线右移，最大效应降低；Dai（10～100μmol·L^-1）对ACh引起的血管环的舒张反应有浓度依赖性的增强作用，且在用阿托品阻断M受体后Dai对KCl引起的收缩的舒张效应减弱。结论 Dai舒张血管效应与抑制内Ca^2＋释放和外Ca^2＋内流有关；Dai对血管环的直接舒张作用与ACh相似，也是通过激动内皮上的M受体释放EDRF等而引起的，且具有内皮依赖性。

英文摘要：

To study the relationship between the vasodilatation effects of daidzein and M-receptor in the endothelial cell, extracellular Ca^2＋ and intracellular Ca^2＋ Methods Measurement of isometric force of rabbit thoracic aortae rings Dai （ 3 ～100μmol· L^- 1 ） was performed. Results significantly inhibited the contractive response of phenyleohrine dependent on intracellular Ca^2＋ release and extracellular Ca^2＋ inflow ; a shift was produced to the right of the concentrationeffect curve of KCl and the maximum response was depressed by Dai（10～100μmol·L^-1 ） ; Dai（10,30, 100μmol· L^-1 ） enhanced the relaxing effect induced by acetylcholine in a concentration-dependent manner, but the relaxing effect was inhibited after using atropine to block the M-receptor. Conclusion The relaxing effect of Dai was related to the inhibition of the receptor-mediated Ca^2＋-influx and Ca^2＋-release; Dai induced direct relaxing effect by activating the M-receptor in the endothelium and releasing EDRF, which was similar to ACh, and this effect was endothelium-dependent.