牛膝总皂苷对大鼠离体胸主动脉环舒张作用的机制研究

目的研究牛膝总皂苷(ABS)对大鼠离体胸主动脉血管环舒张作用及其作用机制。方法采用累积加药法,通过观察ABS对去甲肾上腺素(NE)和KCl预收缩的血管环张力的影响,并观察几种抑制剂对其作用的影响。结果 ABS对NE预收缩的内皮完整和去内皮血管环均有舒张作用,L-硝基精氨酸甲酯(L-NAME)、亚甲蓝(MB)、吲哚美辛(INDO)能显著减弱ABS诱导的血管环舒张作用;钾离子通道阻滞剂对ABS的舒血管效应有明显抑制作用(P<0.05);ABS对KCl预收缩的血管环有良好的舒张作用。结论 ABS的舒血管作用与NO介导途径有关,同时与钾离子通道的开放及血管平滑肌细胞上受体依赖性钙通道和电压依赖性钙通道有关。

Vasodilation effect of total saponins of achyranthes bidentata blume on rat aorta in vitro

Objective To investigate the vasodilation effect of total saponins of achyranthes bidentata blume(ABS) on thoracic aortic of rat and to study its mechanism.Methods The effects of ABS on the NE and KCl-preconstricted aorta rings were determined by organ bath technique,and some inhibitors was used to explore the mechanism.Results ABS caused relaxation in NE-preconstricted thoracic aortas with or without endothelium.NG-nitro-L-arginine methylester(L-NAME),methylene blue(MB),indomethacin(INDO) significantly inhibited the vasodilation of ABS action on thoracic aortas preconstricted by NE.Tetraethyl ammonium(TEA),BaCl2 and glibenclamide(Gli) attenuated the vasodilation effect of ABS,and ABS also vasodilated thoracic aortas preconstricted by KCl.Conclusion The results indicate that ABS relaxes vascular smooth muscle in a certain endothelium-dependent manner,and the mechanisms seem to be related with the openness of K+ channels as well as the blockage of receptor-dependent and potential-dependent calcium channels in the cell membrane of smooth muscles.