大豆黄酮血管舒张作用与血管内皮的关系

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Ca2+性收缩和依外Ca2+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Ca2+释放和外Ca2+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。

Relationship between vasodilatation effect of daidzein and vascular endothelium

Aim To study the relationship between the vasodilatation effects of daidzein and M-receptor in the endothelial cell, extracellular Ca2+ and intracellular Ca2+.Methods Measurement of isometric force of rabbit thoracic aortae rings was performed. Results Dai(3～100 μmol·L-1 ) significantly inhibited the contractive response of phenyleohrine dependent on intracellular Ca2+ release and extracellular Ca2+ inflow;a shift was produced to the right of the concentration-effect curve of KCl and the maximum response was depressed by Dai(10～100 μmol·L~ -1 ); Dai(10,30,100 μmol·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 Ca2+ -influx and Ca2+-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.