双环醇减轻超氧阴离子诱导的大鼠胸主动脉舒张功能损伤

Bicyclol protects rat thoracic aorta from superoxide anion-induced inhibition of vascular relaxation

目的：探讨双环醇（bicyclol）对超氧阴离子（O2）诱导的血管舒张功能损伤的影响。方法：采用离体器官灌流技术,观察bicyclol对离体大鼠胸主动脉环张力的影响。采用焦酚（O2的供体）建立O2损伤模型,观察bicyclol预孵育对氧化应激损伤后血管内皮依赖性舒张功能的改善作用。结果：bicyclol（10-8~10-5mol/L）对由苯肾上腺素预收缩的内皮完整主动脉环产生舒张作用,该作用可被NO合酶抑制剂L-NAME和环氧化酶抑制剂吲哚美辛阻断。500μmol/L焦酚可引起乙酰胆碱诱导的主动脉环内皮依赖性舒张反应减弱,bicyclol（10-5mol/L）预孵育45 min可减轻焦酚的损伤作用。对于吲哚美辛处理的主动脉环,bicyclol（10-5mol/L）可抑制焦酚所致的血管舒张反应降低,但这一效应未见于L-NAME处理的主动脉环。结论：bicyclol具有内皮依赖性舒血管作用,并能对抗O2引起的血管舒张功能损伤,该作用通过NO途径介导。

Objective： To investigate the effect of bicyclol on vascular oxidative stress injury induced by superoxide anion.Methods： Rat thoracic aortic rings were isolated for isometric tension recording using organ bath technique.Superoxide arterial injury was induced by pyrogallol exposure,and the effect of bicyclol on endothelium-dependent relaxation was evaluated.Results： Bicyclol（10-8～10-5 mol/L） relaxed endothelium-intact aortic rings precontracted by phenylephrine.This effect was abolished by L-NAME,an inhibitor of nitric oxide synthase and indomethacin,an inhibitor of cyclooxygenase.Exposure to pyrogallol（500 μmol/L） resulted in decrease of acetylcholine（ACh）-induced endothelium-dependent relaxation in aortic rings,and pre-incubation of bicyclol（10-5 mol/L） for 45 min improved the relaxation attenuated by pyrogallol.In aortic rings pre-treated with indomethacin,bicyclol increased the ACh-induced relaxation that was inhibited by pyrogallol（500 μmol/L）.This effect was not found in aortic rings pretreated with L-NAME.Conclusion： Bicyclol has endothelium-dependent vasodilating effect on rat thoracic aorta and improves vascular function by attenuating oxidative stress.Nitric oxide from endothelium is involved in the anti-oxidative effect of bicyclol.