不同浓度甲醛吸入对心肌缺血再灌注时脑组织氧化损伤的影响

Effects of inhaled formaldehyde at different concentrations on oxidative damage of brain tissues during myocardial ischemia-reperfusion

目的探究环境中不同浓度的甲醛吸入对心肌缺血-再灌注时远端脑组织的氧化损伤作用,以及静脉注射抗氧化剂还原型谷胱甘肽(GSH)是否能够有效减轻该损伤。方法大鼠经左冠状动脉前降支结扎缺血30 min后再灌注3 h,建立心肌缺血-再灌注模型,在缺血的同时开始吸入不同浓度甲醛进行染毒至再灌注结束。GSH(120 mg/kg)溶于1 ml 0.9%氯化钠注射液中于再灌注开始后1 min内静脉滴入。实验结束取脑组织,测定超氧化物歧化酶(SOD)活性、谷胱甘肽过氧化物酶(GSH-Px)活性以及丙二醛(MDA)含量变化。结果与缺血/再灌注组相比,甲醛21 mg组或甲醛42 mg组SOD及GSH-Px活性明显下降,MDA含量明显升高,差异有统计学意义(P<0.05)。注入GSH后,SOD及GSH-Px活性增加,MDA含量下降,组间比较差异具有统计学意义(P<0.05)。结论环境中不同浓度的甲醛吸入与心肌缺血/再灌注对脑组织造成的氧化性损伤具有协同效应。GSH可显著减少脑组织中因心肌缺血/再灌注产生的大量氧自由基,有效减轻甲醛吸入与心肌缺血/再灌注等造成的机体脂质过氧化损伤。

Objective To investigate the effects of inhaled formaldehyde at different concentrations on oxidative damage of the brain tissues during myocardial ischemia reperfusion,and determine whether intravenous injection of the antioxidant reduced glutathione(GSH)can effectively alleviate the damage.Methods The studied rats were ligated of the left anterior descending coronary artery for 30 minutes and then reperfused for 3 hours to establish a myocardial ischemia-reperfusion model.During the ischemia phase,inhalation of formaldehyde at different concentrations was started as an exposure to poison until the end of reperfusion.GSH(120 mg/kg)dissolved in 1 ml normal saline was irrigated intravenously within 1min immediately after the start of reperfusion.At the end of the experiment,the rat brain tissues were harvested for measuring superoxide dismutase(SOD)activity,glutathione peroxidase(GSH-Px)activity and the changes in malondialdehyde(MDA)content.Results Compared with the ischemia/reperfusion group,the SOD and GSH-Px activities were lowered,and the MDA content was increased in the formaldehyde 21 mg and 42 mg groups,with significant differences(P<0.05).After irrigation of GSH,the activities of SOD and GSH-Px increased and the MDA content was decreased,with significant differences between groups(P<0.05).Conclusion Inhalation of environmental formaldehyde at varying concentrations have synergistic effects with myocardial ischemia/reperfusion in oxidative damage of brain tissue.GSH can significantly reduce the massive production of oxygen free radicals in brain tissues caused by myocardial ischemia/reperfusion,and effectively ameliorate the lipid peroxidation damage of the body caused by formaldehyde inhalation and myocardial ischemia/reperfusion.