Rho激酶在远距缺血后处理抗心肌缺血/再灌注损伤中的作用

Role of Rho-kinase in remote ischemic postconditioning against myocardial ischemia/reperfusion injury

目的探讨Rho激酶在远距缺血后处理(remote ischemic postconditioning,RIPost C)中的作用及其可能的作用机制。方法 30只♂SD大鼠随机分为假手术组(Sham)、缺血/再灌注组(I/R)、远距缺血后处理组(RIPost C)、缺血/再灌注+Rho激酶阻断剂法舒地尔组(I/R+Fas),远距缺血后处理+Rho激酶激动剂溶血磷脂酸组(RIPost C+LPA),每组6只。全程监测动脉血压和Ⅱ导联心电图,实验结束后测定血浆肌酸激酶(CK)、乳酸脱氢酶(LDH)活性变化,HE染色观察心肌组织形态学变化,TTC染色法评价心肌梗死面积,Western blot测定磷酸化肌球蛋白轻链(p-MLC)蛋白表达。结果与Sham组相比,其余各组MAP、HR均下降,ST段增高;与I/R组相比,RIPost C和I/R+Fas组MAP、HR升高,ST段降低,心肌组织病理形态有明显改善,炎性细胞浸润减轻,心肌梗死面积降低,CK、LDH释放减少,p-MLC表达降低;与RIPost C组相比,RIPost C+LPA组减弱了RIPost C的作用,抑制了上述指标的恢复。结论 Rho激酶信号通路可能参与了远距缺血后处理抗心肌缺血/再灌注损伤的作用。

Aim To explore the role of Rho-kinase in remote ischemic postcondi-tioning and its possible mechanism. Methods Thirty male Sprague-Dawley rats were divided into five groups（ n = 6） ： sham group（ Sham）,ischemia/reperfusion group（ I/R）,remote ischemic postconditioning group（ RIPost C）,I/R with Rho-kinase inhibitor fasudil group（ I/R ＋ Fas） and RIPost C with Rho-kinase activator lysophosphatidic acid group（ RIPost C ＋ LPA）. Throughout the whole process of experiment,mean arterial pressure（ MAP）,heart rate（ HR） and Ⅱ lead electrocardiogram were continuously monitored. At the end of the reperfusion,plasma creatine kinase（ CK） and lactate dehydrogenase（ LDH） were measured. Myocardial histopathologic changes were observed by hematoxylin and eosin（ HE）staining. Infarct size was measured using 2,3,5-triphenyltetrazolium chloride（ TTC） staining. The expressions of phospho-myosin light chain（ p-MLC） were detected with Western blot analysis. Results Compared with Sham group,the MAP and HR of other groups decreased,while the amplitude of ST segment increased.Compared with I/R group,MAP and HR increased,the amplitude of ST segment decreased,plasma CK and LDH activity decreased,myocardial pathological morphology and infarct size were improved significantly,infiltration of inflammatory cells was reduced,and the expression of p-MLC decreased in RIPost C and I/R＋ Fas group. Compared with RIPost C group,RIPost C＋ LPA group attenuated the effects of RIPost C,and the recovery of the above indicators were inhibited.Conclusion Rho-kinase signaling pathway might mediate remote ischemia postconditioning against myocardial ischemia/reperfusion injury.