大鼠局灶性脑缺血再灌注早期DNA修复功能的研究  

DNA-repairing function at early stage of focal cerebral ischemia-re perfusion in rats

作　　者：万群[1] 万琪[1] 王颖[2] 张光运[1] 张志军[1] 魏东[1] 

机构地区：[1]解放军第四军医大学西京医院神经内科,陕西省西安市710032 [2]解放军第四军医大学神经科学研究所,陕西省西安市710032

出　　处：《中国临床康复》2004年第13期2472-2473,共2页Chinese Journal of Clinical Rehabilitation

摘　　要：目的:探讨大鼠脑缺血再灌注不同时相DNA修复酶Ku70的表达变化及其意义。方法:采用免疫组织化学方法检测大鼠大脑中动脉阻塞(MCAO)2h再灌注不同时间点缺血脑组织区Ku70的表达情况。结果:正常对照组、假手术组、手术组非缺血侧大脑半球Ku70广泛表达,定位于细胞核;手术组缺血侧尾壳核于再灌注0.5h、额顶叶皮质于再灌注2hKu70阳性细胞数开始减少犤分别为(83.3±5.3)及(105.5±5.1)个/视野,t=2.561及14.934,P均<0.05犦,于再灌注6h,上述区域Ku70表达水平显著降低犤分别为(23.8±3.8)及(37.8±4.3)个/视野,t=3.149及20.771,P均<0.01犦,并持续至再灌注48h。结论:大鼠局灶性脑缺血再灌注早期,DNA修复酶Ku70在损伤区域的表达水平降低,提示再灌注早期DNA修复功能降低,在促进缺血再灌注区域细胞损伤中可能起有重要作用。AIM:To study the expressions of DNA repair protein Ku70 at different intervals following focal cerebral ischemia-reperfusion in rats. METHODS:Immunohistochemical method was used to evaluate the expression of Ku70 protein at different reperfusion time 2 hours after middle cerebral artery occl usion(MCAO) in the rats. RESULTS:Immunohistochemical staining showed that the expressions of Ku70 prote in in the nuclei were found widely in the normal control group, sham operation g roup and controlateral nonischemic hemisphere.In the ischemic hemisphere of the operation group,the number of Ku70 positive cells began to decrease 0.5 hour aft er reperfusion in the caudate putamen and in the cortex 2 hours after reperfusio n, which were(83.3±5.3) and (105.5±5.1) per visual field respectively(t=2.561, 14.934,P< 0.05). The number of Ku70 positive cells was decreased remarkably in t he entire damaged area as early as 6 hours after reperfusion, which were(23.8±3 .8) and(37.8±4.3) per visual field(t=3.149,20.771,P< 0.01), and remained to be reduced until 48 hours. CONCLUSION:At early stage of focal cerebral ischemia,the expression of DNA rep air enzyme Ku70 in the damaged area were reduced remarkably,suggesting that DNA -repairing function is weakened at early stage and may play an important role i n accelerating cell death in the damaged regions.

关 键 词：大鼠 局灶性脑缺血 再灌注损伤 早期DNA修复 免疫组织化学 检测 

分 类 号：R743.31[医药卫生—神经病学与精神病学]