能量限制对APP/PS1双转基因大鼠脑内Aβ的影响

摘要

目的 探讨能量限制(CR)对APP/PS1双转基因大鼠脑内Aβ的影响,并探讨其可能的机制.方法 将24只5月龄APP/PS1双转基因痴呆大鼠随机分为对照组、CR-1组、CR-2组,分别给予自由进食、正常进食量的80%及70%饲养4w,通过Morris水迷宫测试认知能力及免疫组织化学染色观察脑内Aβ阳性细胞数.结果 在Morris水迷宫测试在定位航行实验第5天,CR-2组大鼠的逃避潜伏期较对照组明显缩短(P<0.05),穿越平台次数明显增多(P<0.05);而CR-1组较对照组无显著差异(P>0.05).CR-2组海马区的Aβ阳性细胞数低于对照组,差异有统计学意义(P<0.05);而CR-1组较对照组差异无统计学意义(P>0.05).结论 70%的CR可以改善APP/PS1双转基因大鼠的认知能力,其机制可能与减少大鼠脑内Aβ的沉积有关.%Objective To discuss the impact of calorie restriction(CR)on β-amyloid protein(Aβ) of APP/PS1 double transgenic mice, and investigate the probable mechanism.Method Twenty-four 5-month old APP/PS1 double transgenic mice were divided into three groups randomly: control, CR-1 and CR-2 group,feeding the normal, 80% and 70% calorie diets respectively for 4 weeks. After that, Morris water maze was taken to evaluate the memory performance and immunochemistry staining was used to observe the Aβ deposition in hippocampus.Results On the fifth day of goal-oriented navigation in Morris water maze, the escape latency was shorter compared CR-2 group with the control(P<0.05), while the platform crossing frequency increased(P<0.05), with statistic differences. But no statistic differences showed between the CR-1 and control groups(P>0.05). Immunohistochemistry showed that Aβ positive cells at hippocampus in CR-2 group were fewer than the control with statistic difference(P<0.05), but no difference existed between CR-1 and control group(P>0.05).Conclusion 70% CR could improve the cognition of APP/PS1 transgenic mice,which probable mechanism involves in decreasing the Aβ deposition in the brain of mice.