非创伤缺血预处理对大鼠缺血再灌注心肌的作用

Effects of non-wounded ischemic preconditioning on myocardium ischemic reperfusion injury in rats

目的：确定非创伤性缺血预处理对大鼠缺血／再灌注（Ｉ／Ｒ）心肌损伤是否具有对抗作用，以扩展缺血预处理的实际应用。方法：采用非创伤性下肢缺血预处理及经典缺血预处理的动物模型，比较两种处理方法对Ｉ／Ｒ心肌损伤的效应。实验动物分４组：正常对照组（ＮＣ，ｎ＝８），开胸旷置５０ｍｉｎ；缺血／再灌注组（Ｉ／Ｒ，ｎ＝１２），结扎冠脉３０ｍｉｎ，再灌注２０、１８０ｍｉｎ；经典缺血预处理组（Ｃ－ＩＰＣ，ｎ＝１２），按经典Ｍｕｒｙ法复制；非创伤性下肢缺血预处理组（Ｎ－ＷＩＰＣ，ｎ＝１２），捆绑双下肢５ｍｉｎ，松开５ｍｉｎ，反复４次后，阻断冠脉３０ｍｉｎ，再灌２０、１８０ｍｉｎ。以左室功能，心肌梗塞范围，血清肌酸激酶（ＣＫ）及心肌组织丙二醛（ＭＤＡ）含量、超氧化物歧化酶（ＳＯＤ）活性为观察指标。结果：与Ｉ／Ｒ组相比，Ｎ－ＷＩＰＣ组与Ｃ－ＩＰＣ组均显著缩小Ｉ／Ｒ后的心肌梗塞范围（Ｐ＜００１）；明显恢复Ｉ／Ｒ后的左室功能（Ｐ＜００５，００１）；减轻自由基对心肌的损害：血清ＣＫ，心肌ＭＤＡ含量显著降低（Ｐ＜００１）。Ｎ－ＷＩＰＣ组还使心肌ＳＯＤ活性增高（Ｐ＜００５）。结论：非创伤性下肢缺血预处理与经典缺血预处理可诱发同等强度的?

AIM:To determine whether the non-wounded legs repeated-brief ischemic preconditioning has protective effects to extend the further application of IPC.METHODS:Two animal models which were the non-wounded legs repeated-brief ischemic preconditioning and the classical ischemic preconditioning,were produced to be compared with their protective effects on myocardial ischemic-reperfusion injury.Rats were divided into four groups:normal control group (NC, n =8),ischemic-reperfusion group (I/R, n =12), calssical ischemic preconditioning(C-IPC, n =12), and non-wounded legs ischemic preconditioning group(N-WIPC, n =12).Changes in left ventricular functions,myocardial infarct size,creatine kinase(CK) in serum and MDA,SOD of myocardium were investigated. RESULTS:Compared with I/R group, non-wounded legs ischemic preconditioning and classical ischemic preconditioning could: (1)Reduce the myocardial infarct size( P <0 01);(2)Improve the left ventricular function;(3)Decrease the content of MDA of myocardium and CK in serum( P <0 01).Besides, the activity of SOD of myocardium increased in non-wounded legs ischemic preconditioning group. CONCLUSION:Non-wounded legs ischemic preconditioning has protective effects on the I/R myocardium approximating to classical ischemic preconditioning.