Effects of Ischemic Postconditioning on Myocardial Apoptosis in Non-infarct Zone in Pigs with Myocardium

［Abstract］Objective　To investigate the effect of ischemic postconditioning on myocardial apoptosis in non-infarct zone in pigs with myocardium．Methods　Fifteen Diannan small-ear pigs were divided into three groups（n＝5 pre group） randomly：（1）Sham-operated（S）group：A balloon catheter was positioned in the mid-distal left anterior descending（LAD）via right femoral artery under fluoroscopic guidance，without ischemia；（2）Ischemia-reperfusion （I/R） group: the balloon was inflated and occluded the LAD for 60 minutes；（3）ischemic postconditioning（Postcond）group: pigs were treated the same as I/R group and 8 cycles of 30 s R and 30 s I before reperfusion. After 72 h of reperfusion，infarction size were measured by 2，3，5－triphenyltetrazolium chloride（TTC）staining．The apoptotic cells in the non-infarct zone myocardium was determined with terminal deoxynucleotidyl transferase-mediated dUTP-fluorescence in nick end（TUNEL） method，and apoptosis-related molecules were studied by immunohistochemical analysis. Result　After 72h of reperfusion，the infarction size，apoptotic index（AI）of non-infarcted zone，the levels of Bax protein expression，and Bax/Bcl-2 ratio were significantly lower in Postcond group than those in I/R group（P＜0.05）．Conclusion　Ischemic postconditioning can reduce myocardial apoptosis in non-infarct zone and maybe play a myocardial protection effect.