【摘要】 目的:检测不同运动负荷对老龄大鼠认知能力的影响并探讨其可能的机制。方法:40只16月龄雄性Wistar大鼠随机分为4组:即对照组(不游泳)、小负荷组(游泳15 min)、中负荷组(游泳30 min)和大负荷组(游泳60 min)。各负荷组大鼠经8周无负重游泳训练后,进行八臂迷宫实验观察各组大鼠的行为学表现;运用实时定量PCR和免疫组化实验检测各组大鼠海马神经组织(VEGF)、血管内皮生长抑制因子(VEGI)的表达情况。结果:(1)与对照组相比,大负荷组大鼠的参考记忆错误次数和工作记忆错误次数均显著增多(P <0. 05,P <0.01);中负荷组大鼠各检测指标与对照组相比无统计学差异(P> 0. 05);小负荷组大鼠的工作记忆错误次数和觅食完成时间均显著降低(P <0. 05)。(2)与对照组相比,小负荷组大鼠海马组织VEGF mRNA和蛋白表达水平均显著上调(P <0. 01),VEGI mRNA和蛋白表达水平均显著下调(P <0. 05,P <0. 001);大负荷组大鼠海马组织VEGF mRNA和蛋白表达水平均显著下调(P <0. 01,P <0. 001),VEGI mRNA和蛋白表达水平均上调(P <0. 01,P <0. 001);中等负荷组大鼠海马神经组织VEGF和VEGI mRNA和蛋白的表达水平与对照组相比无统计学差异(P> 0. 05)。结论:小负荷运动有利于改善老龄大鼠的认知能力,中等负荷对此改变不大,而大负荷运动则对于老龄大鼠的认知能力具有损伤作用。其机制可能为小负荷运动能够上调老龄大鼠海马神经组织VEGF表达、下调VEGI表达,促进血管的新生,进而改善海马神经元的增殖;大负荷运动组则表现出了相反的影响趋势。更多还原

【Abstract】 Objective: Effects of different exercise loads on cognitive ability in aged rats and its mechanisms.Methods: Forty male Wistar rats aged 16 weeks were randomly divided into 4 groups: control group( no swimming),low load group( 15 min swimming),medium load group( 30 min swimming) and high load group( 60 min swimming).After8 weeks no-weight swimming training in each load group,eight-arm maze test was performed to observe the behavioral performance of each group.Real-time quantitative PCR and immunohistochemistry were used to detect the expression of vascular endothelial growth factor( VEGF) and vascular endothelial growth inhibitory factor( VEGI) in hippocampal neurons in each group.Results:( 1) Compared with control group,the number of reference memory errors and working memory errors in high load group increased significantly( P < 0.05,P < 0.01); There was no statistical significance in medium load group( P > 0.05).The number of working memory errors and the completion time of foraging in low load group weresignificantly decreased( P < 0.05).( 2) Compared with control group,the expression of VEGF mRNA and protein in hippocampus of low load group were significantly up-regulated( P < 0.01),and the expression of VEGI mRNA and protein were significantly down-regulated( P < 0.05,P < 0.001).The expression of VEGF mRNA and protein in hippocampus of rats in high load group were significantly down-regulated( P < 0.01,P < 0.001),and the expression of VEGI mRNA and protein were up-regulated( P < 0.01,P < 0.001).The expression of VEGI and VEGF mRNA and protein in hippocampus of medium load group had no significantly differences( P > 0.05).Conclusion: Low load exercise is beneficial to improve the cognitive ability of aged rats.The medium load has little change,while the high load has a damaging effect.The mechanism may be that low load exercise can up-regulate the expression of VEGF and down-regulate VEGI in hippocampal neurons of aged rats,promote the regeneration of blood vessels,and then improve the proliferation of hippocampal neurons.The high load exercise group shows the opposite trend.更多还原