摘要
目的探讨后适应对小鼠心肌再灌注损伤的影响以及不同缺血时间窗的后适应心脏保护作用的差异。方法96只成年C57/BL小鼠随机分为缺血时间30、45min和60min的三组,每组又分为后适应和缺血再灌注两种处理。通过开胸结扎左冠状动脉造成急性心肌梗死,在完全再灌注早期给予反复短暂再通/闭塞的缺血后适应。采用Evansblue和TTC染色的方法确定缺血心肌和梗死心肌面积,并测定血清的心肌酶含量、心肌超氧化物歧化酶(SOD)活性与丙二醛(MDA)水平以及血流动力学指标。结果缺血30min后适应组、缺血45min后适应组心肌梗死面积分别比相同缺血时间的再灌注对照组减少53.1%和31.2%,差异均具有统计学意义(P<0.01),缺血后适应可明显降低血清心肌酶、提高心肌SOD的活性以及改善血流动力学的恶化;缺血60min后适应组梗死心肌面积无明显降低,差异无统计学意义(P>0.05)。结论小鼠心肌处于轻中度水平的缺血损伤,在恢复冠脉血流的早期施行缺血后适应可以有效地减少心肌再灌注损伤,但随着缺血时间的延长,心肌保护作用就明显减弱或消失。
Objective To evaluate different cardioprotective effects of postconditioning of different ischemia duration on mouse healt during reperfusion. Methods 96 adult C57/BL mice were randomly divided into three groups according to myocardial ischeamia duration： 30 min,45 min and 60 min. The mice in each group underwent two different treatments： postconditioning or ischeamia reperfusion. Postconditioning group underwent open-chest surgery to induce left coronary artery （LCA） occlusion and reperfused for 3 h. After LCA occlusion, several cycles of 10-second reperfusion followed by 10-second LCA reocclusion were applied during the early minutes of reperfusion. The ischemic size and infarct size were measured by Evans blue and TTC staining, respectively. The level of plasma CK, levels of MDA and SOD activity in myocardium in different groups were evaluated by hemodynamic assessment. Result With 30 min occlusion and 45 min occlusion, the infarct sizes were significantly reduced in IPC1 and IPC2 groups （by 53.1% and 31.2%, respectively, P 〈 0.01 ）. Meanwhile, the level of plasma C K and the level of MDA in myocardium were decreased, the level of SOD was increased, and the hemodynamics was improved by postconditioning. But there was no significant reduction in infarct size in the group of 60 min ischemia duration posconditioning （P 〉 0.05）. Conclusions Ischemia postconditioning at onset of reperfusion obviously reduces myocardial injury in mice model. The cardioprotection afforded by postconditioning is limited to mild to moderate myocardial injury and the cardioprotection is lost in mice with severe myocardial injury and longer ischemia duration.
出处
《中国实验动物学报》
CAS
CSCD
2008年第2期127-131,共5页
Acta Laboratorium Animalis Scientia Sinica
基金
新疆高校科研计划创新研究群体基金(编号:XJEDU2005G03)
新疆教委内科重点学科基金(编号:200501)
关键词
缺血时间窗
缺血后适应
再灌注损伤
小鼠心肌
Ischemia duration
Ischemia-reperfusion injury
Postconditioning
Mice
myocardium
