大鼠在体心脏缺血后处理模型的建立与优化

Establishment and Optimization of Ischemic Postconditioning Model in Rat Hearts in Vivo

目的建立并优化大鼠在体心脏缺血后处理(I-postC)模型。方法采用冠状动脉左前降支垫扎球囊法建立在体心脏I-postC模型,健康雄性SD大鼠随机分为7组(n=8):缺血/再灌注(I/R)组(冠状动脉左前降支缺血45min/再灌注2h)、缺血预处理(IPC)组(I/R前先行3轮缺血5min/再灌注5min处理)、I-postC组(包括4个亚组,于冠脉缺血45min后先进行3或4轮再灌注30s/缺血30s或再灌注60s/缺血60s后处理后再进行冠脉再灌注)以及假手术(sham)组。氯化三苯四氮唑(TTC)法测定心肌梗死面积,试剂盒检测血浆乳酸脱氢酶(LDH)和心肌组织超氧化物歧化酶(SOD)活性。结果I/R引起明显的心肌梗死和组织损伤,采用冠状动脉左前降支垫扎球囊法进行I-postC可以显著减少I/R后心肌梗死面积,尤以3或4轮再灌注30s/缺血30s组保护作用明显,其梗死区占缺血区百分比分别比I/R组下降30.26%和58.81%(P分别<0.05),与IPC保护效果相近。结论I-postC可以减轻心肌I/R损伤,其中4轮再灌注30s/缺血30s诱导的I-postC在限制心肌梗死面积方面作用最明显,是理想的大鼠在体心脏I-postC模型。

Objective To establish and optimize the ischemic postconditioning（I-postC） model in rat hearts in vivo. Methods The rats were divided into 7 groups as follows（n = 8） ： ischemic/reperfusion（I/R）, ischemic preconditioning（IPC）, I-postC（ including 4 subgroups） and sham groups. The I - postC models were established by repeatedly ligating of left coronary artery with capsule in rat hearts from male SD rats with different cycles and periods. Infarction size was measured by the triphenyhetrazolium chloride（TTC） staining method. Plasma LDH and SOD activity in myocardium were detected with assay kit. Results I-postC induced by repeatedly ligating of left coronary artery with capsule limited the infartion size resulted from I/R. The infarction size as a percentage of the risk zone reduced significantly by 30.26% and 58.81% in groups subjected to 3 and 4 cycles of 30s reperfusion followed by 30s ischemia respectively（P 〈 0.05）. Conclusion I-postC pro- tects myocardium from I/R injury. Among the four subgroups, 4 cycles of 30s reperfusion followed by 30s ischemia have the most optimal cardioprotective effect.