五味子醇乙对大鼠离体胸主动脉内皮依赖性血管舒张作用的研究

Effect of Schisandrol B on Endothelium-dependent Vasorelaxation in Isolated Rat Thoracic Aorta

目的探讨五味子醇乙对大鼠离体胸主动脉条张力的影响及作用机制.方法采用离体血管灌流实验方法,观察五味子醇乙对静息状态及去氧肾上腺素预收缩大鼠胸主动脉条张力变化的影响;通过预孵育一氧化氮合酶(eNOS)抑制剂左旋精氨酸甲酯(L-NAME)和环氧合酶抑制剂吲哚美辛,再采用反转录聚合酶链反应方法检测血管条内皮型eNOS mRNA的表达,探讨内皮来源的血管舒张因子对五味子醇乙舒张血管作用的影响.结果五味子醇乙对静息状态下胸主动脉条张力无显著影响,加入去氧肾上腺素预收缩血管条后,五味子醇乙对内皮完整型血管条具有显著的舒张作用,该作用可被预孵育L-NAME减弱,但预孵育吲哚美辛对五味子醇乙的舒张血管作用无显著影响.此外,五味子醇乙可显著提高胸主动脉条eNOS mRNA的表达.结论五味子醇乙可引起大鼠离体胸主动脉条内皮依赖性血管舒张效应,且其作用机制可能与促进NO的合成有关.

Objective To study the effect of Schisandrol B on isolated thoracic aorta strips in rats and mechanism.Method In vitro vascular perfusion experiment was used to observe the effects of Schisandrol B on resting tension and pre-contracted by phenylephrine in rat thoracic aorta strips.The endothelium-intact strips were incubated with L-NAME(an inhibitor of eNOS)and indomethacin(an inhibitor of cyclooxygenase),respectively,and RT-PCR method was employed to detect eNOS mRNA expression in thoracic aorta for exploring the effect of endothelium derived relaxing factors on the vasorelaxation induced by Schisandrol B.Results Schisandrol B had no significant effect on the resting tension of isolated vascular strips.Schisandrol B produced a significant vasorelaxation on the endothelium-intact aorta strips pre-contracted by phenylephrine,and pre-incubation with L-NAME weakened this action.While,pre-incubation with indomethacin had no vasorelaxative effect induced by Schisandrol B.In addition,Schisandrol B significantly increased the expression of eNOS mRNA in the thoracic aorta.Conclusion Schisandrol B induce endothelium-dependent vasodilation of rat thoracic aorta strips,and its mechanism may be related to promoting the synthesis of nitric oxide.