中文摘要：

目的 研究电刺激小脑顶核后脑缺血再灌注大鼠端粒酶逆转录酶（TERT）的表达及其对线粒体凋亡途径的影响.方法 Wistar雄性大鼠100只,随机分3组：（1）假手术组;（2）造模组;（3）预电刺激组,即电刺激小脑顶核1 h,24 h后制作右侧局灶脑缺血模型,缺血2 h后再灌注,按再灌注时间不同分24、48、72 h亚组.通过HE、TTC染色观察大鼠脑组织形态结构变化及测定脑梗死体积;免疫组化法、末端标记法检测TERT、Bax及TUNEL的表达;免疫荧光双重标记结合激光共聚焦显微镜检测TERT与Bax的细胞共定位情况.结果 预电刺激组脑组织细胞形态改变较造模组轻,且各亚组脑梗死体积（78.1±2.9,83.1±4.5,83.7±4.8）小于造模组（120.9±8.2,137.0±4.2,141.1±3.3）（P＜0.05）.预电刺激组各亚组TERT阳性细胞数（31.1±3.5,30.0±3.4,18.9±3.3）多于造模组（16.1±2.7,16.9±2.4,11.6±3.5）（P＜0.05）,而其TUNEL阳性细胞数（40.2±3.1,54.8±2.8,37.3±2.4）少于造模组（49.6±2.8,67.0±3.7,46.8±3.2）（P＜0.05）.预电刺激组各亚组Bax阳性细胞数与造模组比较差异无统计学意义（P＞0.05）.TERT与Bax部分共定位于胞质,预电刺激组各亚组TERT和Bax共定位阳性细胞数（14.1±1.3,12.9±2.4,9.0±2.0）多于造模组（8.2±1.1,6.3±2.4,6.0±2.9）（P＜0.05）.结论 电刺激小脑顶核可以促进TERT的表达,增加的TERT可能在胞质与Bax结合,阻止了Bax由胞质转位到线粒体膜,参与抑制线粒体凋亡途径.

英文摘要：

Objective To study the effects of cerebellar fastigial nucleus （FN） electrical stimulation on telomerase reverse transcriptase expression and mitochondrial apoptotic pathway in rats with focal cerebral ischemia and reperfusion.Methods A total of 100 adult male Wistar rats were randomly divided into 3 groups： sham operation group, modeling group （2-hour cerebral ischemia, followed by 24, 48 ＆ 72-hour reperfusion） and FN-stimulating group （electrical stimulation of FN for 1-hour one day before 2-hour cerebral ischemia, followed by 24, 48 ＆ 72 -hour reperfusion）.HE （hematoxylin and eosin） and TTC （triphenyl tetrazolium chloride） staining were used to observe the morphological changes in rat brain and measure the ischemic lesion volumes.The expressions of TERT （telomerase reverse transcriptase） and Bax were detected by immunohistochemical methods and apoptotic cells by TUNEL （terminal deoxynucleotidyl transferase dUTP nick end labeling）.The co-expression of TERT and Bax was detected by immunofluorescence double-labeling plus laser confocal microscopy.Results The morphological changes in rat brain were less greater in the FN-stimulating group than those in the modeling group. And the size of the cerebral infarct was significantly smaller in the FN-stimulating group（78.1±2.9, 83.1±4.5, 83.7±4.8）than that in the modeling group（120.9±8.2, 137.0±4.2, 141.1±3.3）（P〈0.05） at all reperfusion time points. As compared with the modeling group（16.1±2.7, 16.9±2.4, 11.6±3.5）, the FN-stimulating group（31.1±3.5, 30.0±3.4, 18.9±3.3）had a significantly larger number of TERT-positive cells （P〈0.05） and a significantly reduced number of TUNEL-positive cells （49.6±2.8, 67.0±3.7, 46.8±3.2 vs 40.2±3.1, 54.8±2.8, 37.3±2.4） （P〈0.05）. The number of Bax-positive cells at different reperfusion time points in the FN-stimulating group was not significantly different from those in the modeling group （P〉0.05）. TERT partially co-localized with Bax in the c