无创肢体缺血预处理对兔心肌电稳定性的影响及机制  

Effects and mechanism of non-invasive limb ischemic preconditioning on electrical stability of rabbits myocardium

作　　者：侯丽芳[1] 冯志强[1] 肖业伟[1] 冉兵[1] 余广[1] 盘强文[1] 

机构地区：[1]泸州医学院生理学教研室,四川泸州646000

出　　处：《中国心脏起搏与心电生理杂志》2011年第5期422-425,共4页Chinese Journal of Cardiac Pacing and Electrophysiology

基　　金：四川省卫生厅资助项目(项目编号:川卫办发[2006]437号)

摘　　要：目的探讨无创肢体缺血预处理(LIP)对兔心肌电稳定性的影响及其机制。方法取兔27只,随机分为:单纯缺血对照组(Ctr组),LIP组,LIP+ATP敏感的钾通道(KATP)抑制剂格列苯脲组(LG组),LIP+丝裂素活化的蛋白激酶(p38MAPK)抑制剂SB203580组(LSB组),闭胸状态下同步记录体表ECG及心内、外膜单相动作电位。分析心肌缺血背景下单相动作电位振幅(MAPA)、单相动作电位复极90%时间(APD90)、0期去极化最大速率(Vmax)和心率、心律失常的类型、发生率及持续时间的变化,实验结束后取心肌组织检测其中超氧化物歧化酶(SOD)、丙二醛(MDA)及一氧化氮(NO)含量。结果缺血后,四组的平均心率、MAPA、Vmax均不同程度地减小,APD90不同程度地延长;LIP能抑制心律失常的发生,使心律失常持续时间缩短。LG组心律失常发生降低,持续时间缩短,LSB组结果与Ctr组相近。与Ctr组比较,LIP组SOD活力升高;其余三组的MDA含量降低;LIP组NO含量升高,而LG组及LSB组亦低于LIP组(P均<0.05)。结论无创肢体缺血预处理具有增强兔心肌电稳定性、减轻心肌氧化损伤的作用,p38MAPK可能为其发挥保护作用的重要途径,KATP则可能仅在抗氧化和改善供血等方面发挥了作用。Objective To investigate the effects and mechanism of non-invasive limb ischemic preconditioning（LIP） on electrical stability of rabbits myocardium. Methods Twenty-seven rabbits were randomly divided into： ischemia control group （Ctr group）, LIP group, LIP ＋ KATP inhibitor glibenclamide group （LG group）, LIP ＋ p38MAPK inhibitor SB203580 group （LSB group）. Surface ECG , endocardium and epicardium MAP were recorded simultaneausly in closedchest state. In the context of myocardial ischemia, the monophasic action potential amplitude （MAPA）, action potential duration of 90% （ APD90）, maximal rate of depolarization （ Vmax） heart rate, the type of arrhythmia, incidence and duration of changes were analysed, and at the end of the experiment, to take detection of superoxide dismntase （ SOD ）, malondialdehyde （MDA） and nitric oxide（NO） levels in myocardial tissue. Result In four groups after ischemic, the average heart rate, MAPA, Vmax were reduced to varying degrees, APD90 prolonged to varying daegrees; LIP could inhibit the occurrence of arrhythmia, and shorten duration of arrhythmia. LG group could reduce the rate of occurrence and duration of arrhythmia, LSB group was similar to Ctr group. SOD in LIP group was significantly higher than that in Ctr group. MDA in other three group were significantly lower than that in Ctr group. NO in LIP group were significantly higher than that in Ctr group, and NO in LG and LSB group were significantly lower than that in LIP group （ all P 〈 0.05）. Conclusion Non-invasive limb ischemic preconditioning could enhance electrical stability of myocardium, reduce myocardial oxidative damage, in which p38MAPK may play a key protective role, but KATP may play a role only in the anti-oxidation and improving the blood supply.

关 键 词：心血管病学 无创肢体缺血预处理 心肌缺血 心律失常 心肌电稳定性 单相动作电位 

分 类 号：R541.7[医药卫生—心血管疾病] R540.41[医药卫生—内科学]