刺五加水提取物对大鼠离体动脉血管的舒张作用

[目的]探讨刺五加水提取物舒张血管的作用.[方法]采用大鼠离体胸主动脉环灌流模型,记录苯肾上腺素预收缩的大鼠离体胸主动脉环张力的变化,观察刺五加水提取物的舒张血管作用.[结果]刺五加水提取物对苯肾上腺素预收缩的大鼠胸主动脉环具有浓度依赖性舒张作用.用一氧化氮合酶抑制剂左旋硝基精氨酸甲酯和鸟苷酸环化酶抑制剂亚甲蓝预处理后,刺五加的舒张血管作用无明显变化.在无钙营养液(含EGTA)环境下,刺五加水提取物对苯肾上腺素收缩有明显的抑制作用.[结论]刺五加水提取物具有浓度依赖性血管舒张作用,此作用与内皮源性的舒张因子一氧化氮无关,可能与抑制血管平滑肌细胞内质网储存钙的释放有关.

Vasodilative effects of the Acanthopanax water extract on thoracic aorta of rats in vitro

OBJECTIVE To study the vasodilative effects and its possible mechanisms of the Acanthopanax water extract. METHODS Isometric tensions of the aortic ring,preconstricted by phenylephrine（PE） were recorded in vitro when the Acanthopanax water extract were cumulatively given to aortic ring. RESULTS The Acanthopanax water extract could relax the aortic ring precontracted by PE. The relaxing effects of the Acanthopanax water extract were not dependent on endothelium,but L-NAME,iNOS inhibitor,and methylen blue（MB）,cGMP inhibitor,did not attenuate the relaxation responses of the Acanthopanax water extract. In the absence of extracellular Ca^2＋,preincubation of the aortic rings with the Acanthopanax water extract significantly reduced the contraction by PE,suggesting that the relaxant action of the the Acanthopanax water extract includes inhibition of Ca^2＋ influx and release of Ca^2＋ from intracellular stores. CONCLUSION The Acanthopanax water extract could induce vasodilative effects by means of inhibition of release of Ca^2＋ from intracellular stores.