缺血预处理时内源性强啡肽与κ阿片受体对缺血再灌注心肌的保护作用  

Protective effects of endogenous dynorphin and kappa opioid receptor in ischemic preconditioning against myocardium ischemia/reperfusion injury

作　　者：叶明翔[1] 樊荣[2] 魏保真[2] 周京军[2] 胡玉珍[2] 王跃民[2] 裴建明[2] 

机构地区：[1]第四军医大学口腔医学系 [2]第四军医大学基础部生理学教研室,陕西西安710033

出　　处：《第四军医大学学报》2009年第17期1541-1544,共4页Journal of the Fourth Military Medical University

基　　金：国家自然科学基金(30770802);全军医药卫生科研基金(06MA203)

摘　　要：目的:研究缺血预处理(IPC)诱导下内源性强啡肽(Dyn)在血浆水平与心肌mRNA水平的变化以及κ阿片受体Dyn对心肌缺血再灌注损伤中的保护作用.方法:将48只大鼠随机分为6组.对照组,假手术组,缺血预处理组(IPC组),缺血再灌注组(I/R组),IPC+I/R组,选择性k阿片受体阻断剂Nor-BNI+IPC+I/R组.用放射免疫法和聚合酶链反应分别测定大鼠血浆Dyn与心肌DynmRNA表达水平,观察κ阿片受体阻断剂Nor-BNI对于大鼠心肌IPC保护作用的影响.结果:大鼠心肌IPC可以使血浆Dyn浓度明显增高(P<0.05),但心肌mRNA水平尚无明显变化.κ阿片受体阻断剂Nor-BNI能够阻断心肌IPC对于I/R组大鼠心肌收缩功能的改善作用.结论:IPC可通过增加血浆Dyn水平激活κ阿片受体产生对心脏功能的保护作用.AIM： To investigate the effects of ischemic preconditioning on endogenous dynorphin content of blood plasma and mRNA of ventricular myocytes in rats and the protective effects of dynorphin and kappa opioid receptor against myocardium ischemia/ reperfusion injury. METHODS： Forty-eight rats were randomly divided into 6 groups： control group, sham group, ischemic preconditioning group （ IPC ）, ischemia/reperfusion group （ I/R ）, IPC ＋ I/R group and Nor-BNI ＋ IPC ＋ I/R （ Nor-BNI, a selective kappa opioid receptor antagonist） （ n = 8, each）. Radioimmunoassay was employed to measure the dynorphin content of blood plasma and polymerase chain reaction（PCR） was used to measure mRNA of ventricular myocytes. The influence of pre-administration of a selective kappa opioid receptor antagonist before IPC was also observed. RESULTS： The level of dynorphin content of blood plasma significantly increased in IPC group compared with that in 30 min sham group（P 〈0.05） ,but mRNA of ventricular myocytes showed no significant difference. Left ventricular systole pressure （LVSP） and ＋ dp/dt max significantly decreased with administration of Nor-BNI （2 mg/kg ） at 10 and 30 min of ischemia as well as 30 min of reperfusion （ timing from 30 min of ischemia） compared with those in IPC ＋ I/R group （ P 〈 0.05 ）. CONCLUSION ： IPC promotes the release of endogeneous dynorphin and increases the level of dynorphin content of blood plasma in rats. Blockade of kappa opioid receptor blunts the protective effects of IPC on the recovery of cardiac function.

关 键 词：缺血预处理 心肌 心肌再灌注损伤 Κ阿片受体 Nor—BNI 血浆强啡肽水平 心肌mRNA 

分 类 号：R33[医药卫生—人体生理学]