缺血预处理对心瓣膜置换术中心肌细胞Bcl-2及线粒体的影响  

Effect of ischemic preconditioning on myocardial Bcl-2 expression and mitochondrial structure during heart valve replacement surgery

作　　者：雷艺炎[1] 陈振光[1] 鲁建军[1] 刘晓冰[2] 庄梅[3] 苏春华[1] 罗红鹤[1] 

机构地区：[1]中山大学附属第一医院胸心外科,广东广州510080 [2]深圳市孙逸仙心血管医院,广东深圳518001 [3]中山大学附属第一医院保健科,广东广州510080

出　　处：《中国病理生理杂志》2010年第4期686-689,共4页Chinese Journal of Pathophysiology

摘　　要：目的:研究体外循环下(CPB)心瓣膜置换术中缺血预处理(IP)对心肌细胞Bcl-2及线粒体的影响。方法:取2004年4月-2004年12月我院接受心脏瓣膜置换手术治疗的患者54例,随机分成2组,IP组(n=22):主动脉阻断前实行单次缺血2min和开放3min的IP方案,阻断主动脉后采用冷晶体心脏停搏液心肌保护进行手术;对照组(n=32):未进行IP方案,余步骤同IP组。比较2组术前和术后射血分数(EF)、短轴缩短百分率(FS)及每搏心输出量(SV)变化,观察肌钙蛋白T(c-TnT)、Bcl-2蛋白表达以及电镜下心肌细胞线粒体的改变。结果:对照组术后EF、FS及SV均较术前降低,P<0.05;IP组术前后EF、FS及SV变化不明显,IP组术后6h、24h、48h、72h及第5dc-TnT水平均低于对照组,且随时间呈下降趋势;2组术前Bcl-2表达无显著差异(P>0.05),术后IP组为19.85±5.88,较术前显著上升(P<0.05);对照组为14.17±3.39,与术前无明显差别(P>0.05)。术后2组Bcl-2表达具有显著差异(P<0.05)。电镜观察:对照组心肌细胞线粒体肿胀,线粒体膜模糊不清,部分线粒体膜破裂;线粒体嵴明显疏松溶解,大量空泡形成;IP组心肌细胞线粒体膜基本完整,线粒体嵴密集,电子密度增高,无空泡形成。结论:IP可能上调心肌抗凋亡蛋白Bcl-2的表达,对心肌细胞线粒体起保护作用,减轻缺血再灌注对心肌细胞的损伤作用,一定程度上维护心脏功能。AIM：To investigate the effect of ischemic preconditioning （IP） on myocardial Bcl-2 expression and mitochondrial structure during heart valve replacement surgery under cardiopulmonary bypass. METHODS： Fifty-four patients were prospectively randomized to receive or not ischemic preconditioning （IP） before cold cardioplegic arrest. Ischemic preconditioning in the IP patients （n=22） was induced by a single 2-min ischemia followed by 3-min reperfusion just before aortic clamping and cold crystalloid cardioplegia for myocardial protection. The control group （n=32） received no ischemic preconditioning before cold cardioplegic arrest. The levels of ejection fraction （EF）,fractional shortening（FS） and stroke volume （SV） in both groups were measured and compared. troponin T （c-TnT） level,Bcl-2 protein expression and microscopic changes of myocardial mitochondrial structure were recorded for each group before and after surgery. RESULTS： The level of EF,FS and SV in IP group was higher than those in control group （P〈0.05）. No significant difference in preoperative c-TnT levels between two groups was observed. The level of c-TnT in IP group was lower than that in control group and with a declining trend over time of 6 h,24 h,48 h,72 h and 5 d after surgery,respectively. The preoperative positive unit of Bcl-2 expression between two groups showed no statistical difference （P 0.05）. Postoperatively,the positive unit of Bcl-2 expression in IP group was 19.85±5.88,significantly increased as compared to the preoperative value （P〈0.05）. In control group,the positive unit of Bcl-2 expression was 14.17±3.39,showed no statistically significant difference to the preoperative value （P〉0.05）. Postoperative Bcl-2 expression between two groups showed a significant difference （P〈0.05）. In the control group,microscopic observation revealed swollen mitochondrion,with a hardly visible or disrupted membrane for some mitochondrion; mitochondrial crista were obviously dissolved a

关 键 词：缺血预处理 蛋白质BCL-2 线粒体 心脏手术 

分 类 号：R542.5[医药卫生—心血管疾病]