Mito-K_(ATP)在七氟醚延迟预处理减轻大鼠心肌缺血再灌注氧化损伤中的作用

Role of Mito-K_(ATP) in Delayed Sevoflurane Preconditioning on Reducing Oxidative Injury Induced by Myocardial Ischemia-Reperfusion in Rats

目的:探讨线粒体ATP敏感性钾通道(mito-KATP)在七氟醚延迟预处理减轻大鼠心肌缺血再灌注(IR)氧化损伤中的作用。方法:健康雄性SD大鼠60只随机分为5组(n=12),假手术(Sham)组、IR组、七氟醚预处理(SPC)组、七氟醚预处理+5-羟基癸酸(SPC+5-HD)组和5-羟基癸酸(5-HD)组。灌注结束时检测血清肌钙蛋白(IcTnI)水平,氯化三苯四氮唑(TTC)染色确定心肌梗死面积。检测心肌丙二醛(MDA)、Ca2+含量、超氧化物歧化酶(SOD)、谷胱甘肽硫转移酶(GST)活性以及谷胱甘肽硫转移酶Mu(GSTM)表达。结果:IR组较Sham组心肌梗死面积和cTnI释放增加,心肌MDA含量和Ca2+浓度增加,SOD、GST活性和心肌GSTM表达降低(P<0.01);SPC组较IR组心肌梗死面积和cTnI释放减少,心肌MDA含量和Ca2+水平也减少,SOD和GST活性以及心肌GSTM增加(P<0.01);SPC+5-HD组较SPC组心肌梗死面积和cTnI释放增加,心肌MDA含量和Ca2+浓度增加,SOD、GST活性和心肌GSTM表达降低(P<0.01)。结论:七氟醚延迟预处理能减轻大鼠心肌缺血再灌注所致氧化损伤,mito-KATP在其中起调节作用。

Objective：To investigate the role of mitochondrial ATP-sensitive potassium channel（mito-KATP） in delayed sevoflurane preconditioning on reducing oxidative injury induced by myocardial ischemia-reperfusion in rats.Methods：Sixty healthy male SD rats were randomly divided into 5 groups（n=12）,the sham group（Sham）,the ischemia-reperfusion group（IR）,the sevoflurane preconditioning group（SPC）,the sevoflurane preconditioning ＋ 5-hydroxydecanoate group（SPC ＋5-HD）and the 5-hydroxydecanoate group（5-HD）.The level of serum troponin I（cTnI） was detected at the end of reperfusion,and the myocardial infarct size（IS） was measured by triphenyltetrazolium chloride（TTC）staining.The levels of Ca2 ＋,malondialdehyde（MDA）,superoxide dismutase（SOD）,glutathione S-transferase（GST）and glutathione S-transferase Mu（GSTM） in the myocardium were determined.Results：After ischemia-reperfusion,there were significant increases in infarct size,serum cTnI release,myocardial MDA and Ca2＋ content in IR group compared with those of Sham group（P 0.01）.But there were decreased infarct size,serum cTnI release,myocardial MDA and Ca2＋ content,and up-regulated activity of SOD,GST and myocardial GSTM expression in SPC group than those of IR group（P 0.01）.Also there were increased infarct size,serum cTnI release,myocardial MDA and Ca2＋ content,and down-regulated activity of SOD,GST and myocardial GSTM expression in SPC＋5-HD group than those of SPC group（P 0.01）.Conclusion：The delayed preconditioning with sevoflurane can reduce oxidative injury induced by myocardial ischemia-reperfusion,in which mito-KATP is an important regulator.