环孢素A后处理对幼兔离体心脏缺血再灌注时心肌线粒体功能的影响

Effect of Cyclosporine A postconditioning on the mitochondria function after myocardial ischemia and reperfusion injury in young rabbits

目的探讨环孢素A(线粒体通透性转换孔的抑制剂)后处理对幼兔离体心脏缺血再灌注时心肌线粒体功能的影响。方法新西兰幼兔28只,体重300～350 g,建立离体心脏Langendorff灌注模型,随机分为4组(n=7)。对照组(Control组)用Krebs-Henseleit液(K-H液)灌注150 min。其他三组用K-H液配置的20 mmol/L高钾溶液5 ml,使心脏停跳,心肌缺血30 min。在恢复灌注的最初20 min内,缺血再灌注组(I/R组)仍灌注K-H液,环孢素A组(CsA组)灌注含0.2μmol/L环孢素A的K-H液,环孢素A加苍术甙(线粒体通透性转换孔的开放剂)组(CsA+Atr组)灌注含0.2μmol/L环孢素A和20μmol/L苍术甙的K-H液,此后三组继续用K-H液灌注100 min。于实验结束时取左心室心肌组织,测定心肌线粒体膜电位和线粒体腺苷酸含量。结果 I/R组和CsA+Atr组线粒体膜电位稳定性显著小于Control组(P<0.05),CsA组与Con-trol组没有显著差异。I/R组和CsA+Atr组的三磷酸腺苷(ATP)含量明显低于Control组(P<0.05),I/R组二磷酸腺苷(ADP)含量高于Control组(P<0.05),I/R组和CsA+Atr组的腺嘌呤核苷酸(AMP)含量也高于Control组(P<0.05),而CsA组的ATP、ADP、AMP含量与Control组之间的差异没有统计学意义。I/R组和CsA+Atr组的左室发展压、最大上升和下降速率均显著低于CsA组(P<0.05)。结论环孢素A后处理对幼兔离体心脏缺血再灌注时心肌线粒体功能具有保护作用,有利于减轻未成熟心肌缺血再灌注损伤。

OBJECTIVE To study the protective effects of cyclosporine A postconditioning on the mitochondrial function after myocardial ischemia and reperfusion injury in young rabbits.METHODS wenty-eight rabbits weighting 300 to 350 grams were sacrificed and the hearts were immediately loaded on the Langendorff apparatus.All hearts were randomly divided into 4 groups（n=7 each）.Control group underwent perfusion with Krebs-Henseleit solution for 150 minutes.The other three groups underwent myocardial ischemia for 30 minutes.During the first 20 minutes of reperfusion,,I/R group received reperfusion with Krebs-Henseleit solution.CsA group underwent reperfusion with Krebs-Henseleit solution and Cyclosporine A 0.2 μmol/L（inhibitor of MPTP）.CsA＋Atr group was reperfused with Krebs-Henseleit solution,Cyclosporine A 0.2 μmol/L and Atractyloside 20 μmol/L（activator of MPTP）.And then followed by reperfusion with K-H solution for 100 minutes.Mitochondrial membrane potential was assayed with Rhodamine 123 fluorescence methods and adenosine phosphates in mitochondria were quantified by high-pressure liquid chromatography.RESULTS Mitochondrial membrane potential in I/R group and CsA＋Atr group was more unstable compared with control group and CsA group（P〈0.05）.Mitochondrial ATP in I/R group and CsA＋Atr group was less than those in Control group（P〈0.05）.Mitochondrial ADP in I/R group and mitochondrial AMP in I/R group and CsA＋Atr group were less than those in control group（P〈0.05）.There were no differences between CsA group and control group in the metabolism of adenosine phosphates.The LVDP, ＋ dp/dtm~ and - dp/dt,,,ax of I/R group aJad CsA ＋Atr group were less than those of CsA group （ P 〈 0.05）. CONCLUSION Cyclosporine A postconditioning could protect the mitochondria function after myocardial ischemia and reperfusion injury in young rabbits.