中文摘要：

目的探讨预电刺激小脑顶核对大鼠脑缺血再灌注后端粒酶逆转录酶（TERT）蛋白表达水平的影响及其抗细胞凋亡作用的可能机制。方法将Wistar雄性大鼠150只采用完全随机数字表法分为单纯造模组及预电刺激组（即电刺激小脑顶核lh，24h后制作右侧局灶性脑缺血模型）。2组均缺血2h后行再灌注，并按再灌注时间不同分为24h、48h、72h亚组（各25只）。分别用TTC染色测定脑梗死体积，Westernblotting检测TERT与Bax蛋白的表达，TUNEL组化染色检测凋亡细胞数．透射电镜观察线粒体超微结构的变化。结果单纯造模组再灌注24h、48h、72h各亚组的脑梗死体积均明显大于预电刺激组相应亚组，差异均有统计学意义（P〈0．05）。预电刺激组再灌注24h、48h、72h各亚组TERT蛋白的相对表达值（0．87±0．51、0．91±0．40、0．80±0．24）较单纯造模组相应亚组（0．73±0．37、0．80±0．51、0．64±0．33）明显增加，TUNEL阳性细胞数（53．60±5．18、64．00±2．37、49．83±4．26）较单纯造模组相应亚组（63．57±3．74、75．40±5．55、60．00±2．37）明显减少，差异均有统计学意义（P〈0．05）。预电刺激组再灌注24h、48h、72h各亚组Bax蛋白水平与单纯造模组相应亚组比较差异无统计学意义（P〉0．05）。预电刺激组冉灌注24h、48h、72h各亚组线粒体损伤级别（1．50±0．41、1．75±0．52、1．33±0．52）均较单纯造模组相应亚组（2．50±0．63、3．08±0．58、2．33±0．411明显减轻，差异有统计学意义（P〈0．05）。结论电刺激小脑顶核可以促进TERT蛋白表达的增加，增加的TERT可能通过保护线粒体来减少缺血区神经元的凋亡。

英文摘要：

Objective To study the effect of electrical pre-stimulation of cerebellar fastigial nucleus （FN） on protein expression of telomerase reverse transcriptase （TERT） in rats with focal cerebral ischemia and reperfusion and its mechanism of mitocbondrial protection. Methods Adult male Wistar rats （n=150） were randomly divided into a vehicle group （2-hcerebral ischemia, followed by 24, 48 and 72 h of reperfusion） and a FN stimulation group （electrical stimulation of the FN for 1-h daily before 2-h cerebral ischemia, followed by 24, 48 and 72 h of reperfusion）. TTC staining was employed to measure ischemic lesion volumes. Western blotting was used to observe TERT and Bax protein expressions. The apoptotic cells were detected by TUNEL assay. Transmission electron microscopy was employed to detect the changes of mitochondrial ultrastructure. Results The size of the cerebral infarct in the vehicle group was significantly larger than that in the FN stimulation group at all reperfusion time points （P〈0.05）. The relative value of TERT protein expression in the FN stimulation group （0.87±0.51, 0.91 ± 0.40 and 0.80±0.24） was also obviously higher than that in the vehicle group （0.73±0.37, 0.80±0.51 and 0.64 ±0.33） at all reperfusion time points （P〈0.05）; however, a significantly reduced number of TUNEL-positive cells in the FN stimulation group （53.60±5.18, 64.00±2.37 and 49.83±4.26） was notedas compared with that in the vehicle group （63.57±3.74, 75.40±5.55 and 60.00±2.37） at all reperfusion time points （P〈0.05）. No significant difference on Bax protein expression was noted between the vehicle group and FN stimulation group （P〉0.05）. The degree ofmitochondrial damage in the FN stimulation group （1.50±0.41, 1.75±0.52 and 1.33±0.52） was also significantly lower than that in the vehicle group （2.50±0.63, 3.08±0.58 and 2.33±0.41） at all reperfusion time points （P〈0.05）. Conclusion TERT protein expression is significantly increased following