芦丁对离体大鼠主动脉环的舒张作用及相关机制

 目的研究芦丁对离体大鼠胸主动脉环收缩张力的作用及其可能作用途径。方法采用累积加药法,检测芦丁对去氧肾上腺素(PE)预收缩的胸主动脉环收缩张力的影响,研究芦丁对血管张力的影响及其机制。结果芦丁(10～160μmol·L^-1)对内皮完整的离体大鼠胸主动脉环具有浓度依赖性舒张作用。芦丁对内皮完整的胸主动脉环的最大舒张反应(R_max)为(44.28±7.48)%。用一氧化氮合酶抑制剂左旋硝基精氨酸甲酯(L-NAME,0.1 mmol·L^-1)、鸟苷酸环化酶抑制剂亚甲蓝(10μmol·L^-1)和环氧合酶抑制剂吲哚美辛(10 mmol·L^-1)预处理后,均可明显减弱芦丁诱导的舒张血管作用;用β受体阻断剂普萘洛尔(10μmol·L^-1)预处理后,芦丁的血管舒张作用不能被阻断。结论芦丁可能是通过NO-鸟苷酸环化酶途径和前列腺素介导机制产生内皮依赖性的血管舒张作用。

Vasodilatation Effects of Rutin in Isolated Thoracic Aorta Rat and Its Underlying Mechanism

OBJECTIVE To determine the possible mechanism in the vasodilatation of rutin on the isolated rat thoracic aorta rings.METHODS Effects of rutin on the contraction of phenylephrine(PE) preconstricted rat thoracic aorta with or without endothelium were determined by organ bath technique.To explore the mechanism,nitric oxide synthase inhibitor L-N(G)-nitroarginine methyl ester(L-NAME),guanylyl cyclase inhibitor methylene blue,cyclooxygenase inhibitor indomethacin,ATP-sensitive K⁺ channel blocker glibenclamide and β-adrenoceptor antagonist propranolol were used.RESULTS Rutin at 10～160 μmol·L^-1 caused dose-dependent vasorelaxation in endothelium-intact rings preconstricted with PE,but had no effect on aorta rings without endothelium.The maximal response(R_max) values calculated from vasorelaxation curves of rutin were(44.28±7.48)%.Pretreatment with L-NAME(0.1 mmol·L^-1) or methylene blue(10 μmol·L^-1) or indomethacin(10 mmol·L^-1) attenuated the vasorelaxation by rutin in endothelium-intact rings.Administration of propranolol(10 μmol·L^-1) did not block the vascular effect of rutin.CONCLUSION The results indicate that the vasodilatation of rutin is via nitric oxide-guanylyl cyclase pathway and prostaglandin-mediated mechanism.