自噬在二氮嗪减轻大鼠离体心脏缺血再灌注损伤中的作用  

Role of autophagy in attenuation of myocardial ischemia-reperfusion injury by diazoxide in isolated rat heart

作　　者：周海燕[1] 李剑[1] 杨礼[1] 王慧华[2] 

机构地区：[1]浙江大学医学院附属邵逸夫医院麻醉科,杭州市310016 [2]浙江大学医学院附属第二医院麻醉科

出　　处：《中华麻醉学杂志》2011年第3期357-359,共3页Chinese Journal of Anesthesiology

基　　金：浙江省科技厅基金（2008C23G2010214）

摘　　要：目的评价自噬在二氮嗪减轻大鼠离体心脏缺血再灌注损伤中的作用。方法清洁级健康雄性sD大鼠32只，体重220—250g，采用随机数字表法，将大鼠随机分为4组（n=8）：缺血再灌注组（I／R组）、二氮嗪组（D组）、自噬抑制剂渥曼青霉素十二氮嗪组（WD组）和渥曼青霉素组（w组）。WD组与w组腹腔注射渥曼青霉素15μg/kg，I／R组与D组给予等容量生理盐水，30min后处死大鼠，制备Langendorff灌流模型，I／R组和w组灌注K．H液、D组和WD组灌注含二氮嗪100μmol／L的K-H液10min，随后停灌20min，再灌注30min。于灌注二氮嗪前即刻、停灌前即刻、再灌注30min时记录心率（HR）、左室舒张末期压（LVEDP）、左心室发展压（LVDP），于再灌注30min时测定心肌组织SOD活性和MDA含量，检测自噬相关蛋白Beclin-1的表达，透射电镜下观察自噬小体形成情况。结果与I／R组比较，D组LVDP和HR、心肌SOD活性和心肌Beclin-1表达水平升高，LVEDP和心肌MDA含量降低（P〈0．05），WD组和w组心肌Beclin-1表达水平降低（P〈0．05），其余指标差异无统计学意义（P〉0．05）；与D组比较，WD组和w组LVDP和心肌Beclin-1表达水平降低，MDA含量升高，w组LVEDP升高，心肌SOD活性降低（P〈0．05）。D组可见大量自噬小体，WD组与I／R组可见少量自噬小体，w组见极少量自噬小体。结论自噬参与了二氮嗪减轻大鼠心肌缺血再灌注损伤的过程。Objective To evaluate the role of autophagy in attenuation of myocardial ischemia-reperfusion （I/R） injury by diazoxide in the isolated rat heart. Methods Thirty-two male SD rats were randomly assigned into 4 groups （ n = 8 each） ： I/R group, diazoxide group （group D）, an inhibitor of autophagy wortmannin ＋ diazoxide group （group WD） and wortmannin group （group W）. The animals were anesthetized with intraperitoneal pento- barbital sodium 40 mg/kg. Their hearts were excised and passively perfused in a Langendorff apparatus with an oxygenated （95% 02- 5% CO2 ） K-H solution at 37℃. The isolated hearts were made globally ischemic for 20 rain followed by 30 min reperfusion. In I/R and W groups, the isolated hearts were perfused with K-H solution for 10 min before ischemia, while the isolated hearts were perfused with K-H solution containing diazoxide 100/Lmol/L for 10 min before ischemia in D and WD groups. The HR, left ventricular end-diastolic pressure （LVEDP） and left ventricular developed pressure （LVDP） were recorded immediately before perfusion with diazoxide, immediately before the end of peffusiou and at 30 min of repeffusion. Myocardial tissues were obtained at 30 min of repeffusion for determination of SOD activity, MDA content and autophagy-related protein Beclin-1 expression （by immuno- histochemistry）. The formation of autophagosomes was observed by transmission electron microscopy. Results Compared with group I/R, LVDP, HR, SOD activity and Beclin-1 expression were significantly increased at 30 min of reperfusion, while LVEDP and MDA content were significantly decreased at 30 min of reperfusion in group D （P 〈 0.05）, and Beclin-1 expression was significantly decreased in WD and W groups （P 〈 0.05）. Compared with group D, LVDP and Beclin-1 expression were significantly decreased, and MDA content was significantly in- creased in WD and W groups, and LVEDP was significantly increased, while SOD activity decreased in group W （ P 〈 0.05）. Microscopic

关 键 词：自噬 二氮嗪 心肌再灌注损伤 

分 类 号：R285.5[医药卫生—中药学]