蛋白摄入水平对早产大鼠学习记忆能力及mTOR表达的影响  

Influence of protein intake in learning and memory capabilities and mammalian target of rapamycin expression in premature rats

作　　者：崔其亮[1] 张慧[1] 苏志文[1] 孙卫文[2] 谭小华[1] 范茜[1] 陈盛强[2] 

机构地区：[1]广州医学院第三附属医院儿科,广州510150 [2]广州医学院神经科学研究所,广州510260

出　　处：《中华神经医学杂志》2015年第1期22-27,共6页Chinese Journal of Neuromedicine

基　　金：2011年广东省第三批科技计划项目（粤科技规划字（2011197号）;广州市医药卫生科技项目（201102A213149）;广州市科技计划项目应用基础研究专项重点项目（2011J4100046）

摘　　要：目的探讨蛋白摄入水平对早产大鼠学习记忆能力及哺乳类动物雷帕霉素靶蛋白（mTOR）表达的影响。方法断奶后的早产仔鼠按随机数字表法分为3组：早产标准蛋白组、早产低蛋白组、早产高蛋白组，从第22日龄起分别予标准蛋白饲料（蛋白质含量18％）、低蛋白饲料（含8％蛋白质1、高蛋白饲料（含30％蛋白质）喂养至实验结束。各组大鼠分别在第6周和第8周进行Morris水迷宫实验．检测早产大鼠学习记忆能力的改变；同期行免疫组织化学染色和Western blotting观察海马mTOR阳性细胞分布及蛋白表达。结果6周龄早产大鼠的逃避潜伏期在第3天和第4天的差异不明显，各组早产大鼠的穿越原平台次数差异无统计学意义（P〉0．051，海马CA1和CA3区mTOR阳性细胞计数差异均无统计学意义（P〉0．05）；8周龄早产大鼠的逃避潜伏期则随训练天数的增加逐渐缩短，早产高蛋白组大鼠的穿越原平台次数明显大于其余2组，同时其海马CA1和CA3区mTOR阳性细胞计数也显著增加，差异有统计学意义（P〈0．051；与6周龄早产高蛋白组大鼠相比较，8周龄早产高蛋白组大鼠的穿越原平台次数显著增加．海马CA1和CA3区mTOR阳性细胞数显著增加，差异有统计学意义（P〈0．05）；Western blotting检测显示各组早产大鼠6周龄时海马mTOR的表达水平差异不明显，8周龄时早产高蛋白组大鼠海马mTOR的表达水平均明显高于其余2组。结论在大脑早期生长发育过程中，早产可能抑制mTOR活性．从而导致早产大鼠学习记忆能力受损；长时间摄入高蛋白营养可显著改善早产大鼠学习记忆能力．其机制可能与上调mTOR表达有关。Objective To study the influence of protein intake in learning and memory capabilities and mammalian target of rapamycin （mTOR） expression in premature rats. Methods Premature rats were randomly divided into three groups after weaning： preterm standard protein group, preterm low protein group and preterm high protein group. After weaning, three groups were respectively fed with standard protein diets （18% protein）, low protein diets （8% protein） and high protein diets （30% protein） until the end of experiment. When rats were at the 6^th and 8^th weeks, they were performed Morris water maze test to assess the learning and memory abilities, and immunohistochemistry and Western blotting were used to observe the mTOR distribution and mTOR protein expression in the hippocampus. Results At the age of 6 weeks, the escape latencies of the premature rats did not change significantly on the 3^rd and 4^th day of the experiment; the frequency of crossing the platform and the mTOR-positive cells in hippocampal CA1 and CA3 regions of each group showed no significant differences （P〉0.05）. At the age of 8 weeks, the escape latencies in finding the platform were shortened with increased training times for premature rats; the frequency of crossing the platform of high-protein premature rats was significantly higher than that in the other two groups （P〈0.05）; and the mTOR expression in the hippocampal CA1 and CA3 regions of high-protein premature rats was also significantly increased as compared with the other two groups （P〈0.05）. High-protein premature rats at the age of 8 weeks had significantly higher frequency of crossing the platform and increased mTOR-positive cells in the hippocampal CA1 and CA3 regions than those at the age of 6 weeks （P〈0.05）. Western blotting also indicated that the hippocampal mTOR protein expression was not significantly different in each group at 6 week-old; the mTOR expression of high-protein premature rats was significantly higher than that in the other two g

关 键 词：蛋白摄入水平 学习记忆能力 哺乳类动物雷帕霉素靶蛋白 早产 

分 类 号：R722.6[医药卫生—儿科]