二氮嗪对冷保存诱导的大鼠供心Smac/DIABLO蛋白表达的抑制作用  

Inhibition of hypothermic preservation-induced Smac/DIABLO protein expression by diazoxide in donor rat myocardium

作　　者：郑鸣之[1,2] 蒋建平[1] 陈文良[2] 张小兵[2] 朱立[3] 沈岳良[3] 陈莹莹[3] 

机构地区：[1]浙江医学高等专科学校药理学教研室,浙江杭州310053 [2]浙江大学基础医学国家理科人才培养基地,浙江杭州310053 [3]浙江大学医学院生理学教研室,浙江杭州310058

出　　处：《中国病理生理杂志》2009年第9期1676-1680,共5页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.30470635)

摘　　要：目的:探讨线粒体ATP敏感性钾离子通道(mitoKATP)开放剂二氮嗪(DE)对离体大鼠供心不同时程冷保存时促凋亡蛋白Smac/DIABLO表达的影响及机制。方法:SD大鼠随机分为3组,包括空白对照组、单纯冷保存组、DE组(Celsior保存液中含30μmol/L DE),后2组又按冷保存时程不同,分别分为3、6、9、12 h组。实验结束后采用原位末端标记染色法(TUNEL)检测心肌细胞凋亡,采用Western blotting法检测心肌组织中caspase-3蛋白及胞浆Smac/DIABLO蛋白表达。结果:(1)在Celsior保存液中加入DE后,心肌细胞凋亡指数及caspase-3蛋白表达显著低于相应单纯冷保存组。(2)DE可使Smac/DIABLO蛋白表达高峰由冷保存6 h延迟至9 h。(3)DE的上述作用可被mitoKATP通道特异性阻断剂5-羟基葵酸盐(5-HD)所取消。结论:DE具有对抗冷保存诱导心肌细胞凋亡的作用,这种保护作用可能与其激活mitoKATP通道和减少促凋亡蛋白Smac/DIABLO表达有关。AIM ： To investigate the effect of a mitochondrial ATP - sensitive potassium channel （ mitoKATP ） opener diazoxide （ DE ） on Srnac/DIABLO protein expressions in rat heart suffered from different duration of hypothermic preservation. METHODS ： The Langendorff model of isolated rat heart was used. After stored in 4 ℃ Celsior solution with or without DE （30 μmol/L） for different time （0, 3, 6, 9 or 12 h）. Cell apoptosis was detected by TUNEL technique. The expression of Smac/DIABLO protein in cytoplasm and total caspase - 3 protein in myocardia tissue was also anaJyzed by Western blotting. RESULTS ： （ 1 ） Compared to the hypothermic preservation groups, DE reduced the percentage of apoptotie cells and the expression of caspase -3 protein in myocardia tissue. （2） The peak of Smac/DIABLO protein expression level appeared at 6 h after hypotherrnic preservation, and which was postponed to 9 h by DE. （3） The above effects of DE were attenuated by a mitoKATP channel inhibitor 5 - hydroxydeeanoate （5 - HD）. CONCLUSION： The findings indicate that in the isolated rat heart, DE protects myocardium against different duration of hypothermic preservation injury via opening of mitoKATP channel and inhibition of Smac/DIABLO protein expression.

关 键 词：心脏保存 线粒体ATP敏感性钾通道 二氮嗪 蛋白质Smac/DIABLO 

分 类 号：R363[医药卫生—病理学]