缺血后处理与缺血预处理联合应用对长时程心肌缺血/复灌损伤的保护作用  

Cardioprotective effect of ischemic postconditioning and preconditioning against prolonged ischemia and reperfusion indued injury in isolated rat heart

作　　者：叶挺梅[1] 高琴[2] 李艳芳[2] 王珏[3] 夏强[2] 

机构地区：[1]浙江丽水学院,浙江丽水323000 [2]浙江大学医学院生理学系,浙江杭州310058 [3]浙江医学高等专科学校,浙江杭州310053

出　　处：《浙江大学学报（医学版）》2007年第1期35-40,共6页Journal of Zhejiang University(Medical Sciences)

基　　金：浙江省科技厅基金资助(2005C30026)

摘　　要：目的:研究缺血后处理与缺血预处理联合应用对长时程缺血引起的缺血/复灌(I/R)损伤的改善作用及其作用机制。方法:采用离体大鼠心脏Langendorff灌流方法,全心停灌60 m in,复灌120 m in复制长时程心肌缺血的I/R模型,测定心室动力学指标和复灌各时间点冠脉流出液中乳酸脱氢酶(LDH)含量。实验结束测定心肌组织form azan含量的变化。结果:在长时程心肌缺血的I/R模型中,缺血后处理能提高心肌细胞的form azan含量,降低复灌期间冠脉流出液中LDH含量,但对心室血流动力学无明显改善。缺血后处理与缺血预处理联合应用不仅能提高心肌细胞的form azan含量,降低复灌期间冠脉流出液中LDH含量,而且能明显改善心室血流动力学各项指标。钙激活钾通道阻断剂pax illine减弱了两者联合应用的作用。结论:在大鼠离体心脏灌流模型上,缺血后处理与缺血预处理联合应用产生加强的心肌保护作用,其机制可能与激活钙激活钾通道的开放有关。Objective： To explore the cardioprotection effect of co-treatment with ischemic postconditioning and preconditioning in ischemia/reperfusion （I/R） injury and the related mechanism. Methods： Male Sprague-Dawley rats were used for Langendorff isolated heart perfusion. The hearts were subjected to global ischemia for 60 min followed by 120 min of reperfusion. The cardiomyocyte viability was measured by MTT-formazan method ,and the cardiac injury was evaluated by the levels of lactate dehydrogenase （LDH） in the coronary effluent. Ventricular hemodynamic parameters were also measured. Results： In 60 min of ischemia and 120 min of reperfusion group, ischemic postconditioning increased formazan content, reduced LDH release, but hemodynamic parameters did not improved. Co-treatment with ischemic postconditioning and preconditioning during the prolonged ischemia further improved the hemodynamic parameters. The calcium activated potassium channel antagonist paxilline attenuated the effect of co-treatment with ischemic postconditioning and preconditioning. Conclusion： Ischemic postconditioning and preconditioning may synergically protect myocardium from severe ischemia injury,which may be related to calcium-activated potassium channel.

关 键 词：心肌缺血 缺血预处理 心肌/预防和控制 心肌再灌注损伤/病理生理学 钾通道 钙激活/代谢 

分 类 号：R542.22[医药卫生—心血管疾病]