【摘要】 目的探讨线粒体缝隙连接蛋白43(Cx43)和活性氧及蛋白激酶Cε(PKCε)信号通路在缺血后处理中的心脏保护作用。方法将40只雄性SD大鼠建立心脏缺血再灌注(IR)损伤模型,随机分为假手术组(Sham组)、IR组、IPC组和IPC+N-乙酰半胱氨酸(NAC)组(腹腔注射NAC 150mg/kg,15min后IPC处理),每组10只。应用伊文思蓝/TTC双染色检测心肌梗死面积,检测乳酸脱氢酶(LDH)及肌酸激酶同工酶(CK-MB)活性,TUNEL检测心肌细胞凋亡,荧光探针测定心肌线粒体活性氧水平,Western blot检测心肌线粒体总Cx43、磷酸化Cx43和PKCε蛋白表达。结果与IR组比较,IPC组心肌梗死面积显著降低[(27.97±4.26)%vs (46.78±3.32)%],心肌酶LDH及CK-MB、心肌细胞凋亡率及线粒体活性氧生成下降;上调线粒体总Cx43、磷酸化Cx43和PKCε蛋白表达。IPC+NAC组大鼠心肌梗死面积、LDH及CK-MB、心肌细胞凋亡较IPC组显著升高(P<0.05),心肌线粒体PKCε蛋白表达较IPC组显著下调(P<0.05)。结论活性氧信号介导IPC心脏保护,该保护作用与线粒体Cx43及PKCε密切相关,Cx43和活性氧及PKCε信号通路在IPC的心脏保护中发挥重要作用。更多还原

【Abstract】 Objective To study the role of mitochondrial Cx43/ROS/PKC signaling pathway and IPC in protecting heart against IR injury.Methods A rat cardiac IR injury model was established and IPC and NAC(150 mg/kg)were administered.Fourty male SD rats were divided into sham operation group,IR injury group,IPC group,and IPC+NAC group(10 in each group).The size of myocardial infarction(MCI)was measured with Evans blue/TTC staining.The activity of LDH and CK-MB was assayed using a biochemical analyzer.The apoptosis of cardiomyocytes was detected with TUNEL staining.Results The size of MCI was significantly smaller,the activity of LDH,CK-MB and mitochondrial ROS and the apoptosis rate of cardiomyocytes were significantly lower while the protein levels of mitochondrial total and phosph Cx43 and PKCεwere significantly higher in IPC group than in IR injury group.The size of MCI was significantly larger,the activity of LDH,CK-MB and mitochondrial ROS and the apoptosis rate of cardiomyocytes were significantly higher while the protein level of mitochondrial PKCεwas significantly lower in IPC+NAC group than in IPC group(P<0.05).Conclusion The Cx43/ROS/PKCεsignaling pathway plays an important role in IPC protecting heart against IR injury.更多还原