双下肢与心肌缺血后处理对缺血再灌注兔心肌细胞凋亡的影响

Effects of limb and myocardial ischemia postconditioning on Cardiac Myocyte Apoptosis after ischemic and reperfusion injury in rabbit heart

目的探讨双下肢与心肌缺血后处理对缺血再灌注兔心肌凋亡的影响。方法选择新西兰大白兔32只,建立兔心肌缺血再灌注模型,随机分为4组(每组8只):①S组,即假手术组,开胸后穿线套环,不收紧结扎线。②I/R组,结扎冠状动脉左前降支30 min,再灌注180 min。③缺血后处理组,④双下肢缺血后处理组。分别在实验结束后,用原位化学法(TUNEL)法观察各组心肌细胞凋亡,免疫印迹法(Western blotting)测各组心肌Bcl-2的表达。结果双下肢与心肌缺血后处理组细胞凋亡均明显小于I/R组,且心肌Bcl-2的表达明显高于I/R组。结论双下肢与心肌缺血后处理可能通过上调Bcl-2蛋白的表达,抑制心肌细胞的凋亡,对缺血再灌注兔心肌产生保护作用。

【Objective】To observe the effects of limb and myocardial ischemia postconditioning on Cardiac Myocyte Apoptosis after ischemic and reperfusion injury in rabbit heart.【Methods】In anesthetized open-chest rabbits,the left anterior descending artery（LAD） was occluded for 30 min,and reperfused for 3 hrs.All rabbits were randomly divided into four groups（n =8 in each group）： sham group;I/R group;myocardial ischemia postconditioniong group;remote postconditioning group.Cardiac myocyte apoptosis was determined by Terminal deoxynucleotidyl Transferase mediated dUTP nick-end labeling（TUNEL） methods.The levels of BCL-2 activity was determined by Western Blot analysis.【Results】In group 2,ischemia/reperfusion caused significant cardiac myocyte apoptotic death.Limb and myocardial ischemia postconditioning produced a significant anti-apoptotic effect as evidenced by a marked reduction of apoptotic index.（19±6%）,（18±7%） vs（28±7%） in I/R group（P 0.05）.The activity of BCL-2 in group 3 and 4 was higher than that of the other groups（P 0.05）.【Conclusion】Limb and myocardial ischemia postconditioning induced cardioprotection by decrease the extent of myocardial apoptosis against ischemia reperfusion injury in rabbits.