下肢缺血预处理对未成熟心肌的保护作用  

Experimental Study of Cardioprotection and Its Mechanisms for Immature Myocardium with Limbs Ischemic Preconditioning

作　　者：杨铁南[1] 孙忠东[1] 尹志伊[1] 胡波[1] 

机构地区：[1]青岛大学医学院附属青岛市立医院胸心外科,山东青岛266011

出　　处：《中国胸心血管外科临床杂志》2010年第1期46-49,共4页Chinese Journal of Clinical Thoracic and Cardiovascular Surgery

摘　　要：目的探讨下肢缺血预处理(LIP)对未成熟心肌保护作用的机制。方法采用下肢缺血预处理动物Langendorff离体心脏灌注模型,将30只日本长耳大白兔采用随机数字表法分为5组:缺血-再灌注损伤(I/R)组(n=6),建立灌注模型,灌注KH液15min转为工作心15min,全心停灌45min,恢复灌注15min改为工作心30min;E1组(n=6),动物麻醉后反复3次阻断双下肢血流5min,松开5min,建立模型,灌注15min转为工作心15min,全心停灌45min,恢复灌注15min改为工作心30min;E2组(n=6),双下肢缺血预处理前静脉注射超氧化物歧化酶至双下肢缺血预处理完毕,重复E1组方法;E3组(n=6),静脉注射蛋白激酶C(PKC)阻滞剂polymyxin(PMB),时间10min,重复E1组方法;E4组(n=6),静脉注射三磷酸腺苷(ATP)敏感性钾通道(mitoKATP)阻滞剂5-HD,时间10min,重复E1组方法。观察左心室功能恢复、心肌含水量(MWC)、血清肌酸激酶(CK)和乳酸脱氢酶(LDH)漏出率、心肌组织ATP和丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、超氧阴离子自由基(O2.-)等指标。结果E1组的左心室功能恢复优于I/R组、E2组、E3组、E4组(P<0.05),ATP含量、SOD活性均优于其它各组(P<0.05),心肌含水量低于其它各组(P<0.05),MDA含量、CK、LDH漏出率低于其它各组(P<0.05);I/R组、E2组、E3组、E4组的以上指标比较均差异无统计学意义(P>0.05)。预处理前、后E1组、E3组、E4组的O2.-差异有统计学意义(P<0.05)。结论下肢缺血预处理对未成熟心肌具有明显的保护作用,其机制是通过PKC通路和mitoKATP通道起作用。Objective To determine the protection effects and mechanisms for immature myocardium with limbs ischemic preconditioning （LIP）. Methods Using the Langendorff perfusion apparatus to perfuse isolated hearts, we randomly divided 30 Japanese long-eared white rabbits into 5 groups, each having 6 rabbits. For the I/R group,after the perfusion model was established, the isolated hearts underwent 15 min of perfusion with KH solution before working for another 15 min . Then perfusion was stopped to cause ischemia for 45 min before reperfusion for 15 min and working for another 30 min. For E1 group, the model was established by 3× LIP （double limbs obstructed for 5 min followed by 5 min reperfusion for 3 times） and then procedures of the I/R group were carried out. For E2 group, before procedures of the Elgroup were done, superoxide dismutase （SOD） was injected till LIP was completed. For E3 group, intravenous protein kinase C （PKC） polymyxin （PMB） was injected for 10 minutes before E1 procedures were repeated. For E4 group, intravenous mitochondrial ATP-sensitive K＋ channels （ mitoKATP ） blocker 5 hydroxydecanoate was injected for 10 min before E1 procedures were carried out. The left ventricular function recovery, myocardial water content （MWC）, creatine kinase （CK） and lactate dehydrogenase （LDH） leakage, malondialdehyde （MDA） and ATP content, SOD activity and superoxygen negative ion （O2- ） content were tested. Results Left ventricular recovery in E1 group was better than other groups （P〈0. 05）. ATP content and SOD activity in E1 group were also better than all other groups （P〈0.05）. MWC in E1 group was lower than other groups （P^0.05）. MDA content, CK and LDH leakage in E1 group were also lower than other groups （P〈0.05）. There was no significant difference of the above indications among I/R,E2,E3 and E4 groups, while the difference of O2- content in El, E3 and E4 groups before and after preconditioning was significant. Conclusion LiP has obvious pro

关 键 词：下肢缺血预处理 未成熟心肌 心肌保护 

分 类 号：R541[医药卫生—心血管疾病]