银杏叶片对衰老大鼠大脑皮层环腺苷酸反应元件结合蛋白表达的影响

Effects of EGb on expression of CREB and pCREB in cortex of aging rats

目的研究银杏叶片对衰老大鼠皮层核转录因子cAMP反应元件结合蛋白（CREB）、磷酸化CREB（pCREB）表达的影响。方法雄性Wistar大鼠分为青年对照组、老年对照组和银杏叶组。银杏叶组大鼠每日灌胃银杏叶片，其余两组动物灌胃等量蒸馏水，共8周。Morris水迷宫实验观察大鼠空间记忆变化，western blot检测皮层CREB、pCREB表达。结果（1）与青年对照组（9．6±2．88，41．55±6．30）比较，老年大鼠逃避潜伏期延长，穿越平台次数（6．8±2．49）、平台象限停留时间（34．92±4．56）减少（P〈0．05）；与老年对照组比较，EGb组大鼠逃避潜伏期缩短，穿越平台次数和平台象限停留时间（9．4±2.63，41．0±6．68）延长（P〈0．05）。（2）老年对照组大鼠皮层CREB、pCREB表达水平分别为（0．70±0．21，0．13±0．05），低于青年对照组（1.07±0．33，0．26±0．04），差异具有显著性（P〈0．05）；与老年对照组比较，银杏叶组大鼠皮层CREB、pCREB表达升高（1．02±0．18，0．18±0．02）（P〈0．05）。结论银杏叶片可能通过上调老年大鼠大脑皮层CREB、pCREB表达改善空间学习和记忆功能。

Objective To investigate effects of Ginkgo biloba extract（EGb） on expression of CREB and pCREB in cortex of aging rats. Methods Male Wistar rats were divided into three groups：young control group, old control group and EGb group. Rats in EGb group were treated with intragastric administration of EGb, while rats in the other two groups were treated with distilled water. The spatial learning and memory were evaluated by Morris water maze, and the expression of CREB,pCREB were detected by western blot. Results （ 1 ） Compared with young control group（9.6 ± 2.88,41.55 ± 6.30）, the swimming time and times through platform in the target quardrant of rats in old control group（6.8 ± 2.49,34.92± 4.56 ） were reduced （P 〈 0.05 ）. The times passing through the platform and the time exploring the target quadrant were more and longer in EGb group（9.4 ± 2.63, 41.0 ± 6.68） than those in old control group（P 〈 0.05 ）. （2）Compared with rats in young control group （1.07 ＋ 0.33,0.26 ＋ 0.04）, relative contents of CREB and p-CREB proteins in cortex （0.70 ±0.21,0.13 ± 0.05 ）were decreased in old control group（P 〈 0.05 ）. CREB and p-CREB Levels were higher in EGb group （1. 02 ± 0.18,0. 18±0.02） than those in old control group （P 〈 0.05 ）. Conclusion EGb can ameliorate spatial learning and memory of rats by increasing the expression of CREB and p-CREB in cortex.