叶酸缺乏与学习记忆及海马突触体膜流动性相关性研究  

STUDY ON RELATIONSHIP BETWEEN THE FOLATE DEFICIENCY ON LEARNING AND MEMORY AND THE HIPPOCAMPAL SYNAPTOSOMAL MEMBRANE FLUIDITY

作　　者：杨慧敏[1] 林茹珠[2] 廖国仪[1] 周冬[1] 孙轶[3] 黄云祖[1] 

机构地区：[1]暨南大学医学院第一附属医院儿科,广州510632 [2]中山市人民医院儿科,528400 [3]广州医学院第一附属医院儿科,广州510260

出　　处：《营养学报》2002年第4期357-362,共6页Acta Nutrimenta Sinica

基　　金：广东省自然科学基金资助项目 ( No.980 70 0 )

摘　　要：目的 :　探索叶酸缺乏对离乳大鼠学习记忆能力与海马突触体膜流动性的影响。方法 :　 5 4只刚离乳的健康雄性 SD大鼠 ,随机分成三组 :实验组 (FD)、对饲组 (PF)和对照组 (AL)。实验组饲去叶酸的 RHAA配方饲料 ,另二组饲以添加叶酸 8mg/ kg的 RHAA饲料 ,对饲组按实验组的进食量加以控制 ,对照组不控制进食。分别于饲养第 2和第 6 w末测定血清叶酸 (SFA)浓度和进行 Morris水迷宫测试大鼠的学习记忆能力 ,记录平均逃避潜伏期和分析原平台象限游泳距离占游泳总距离的百分比 ,分离海马突触体 ,透射电镜作形态学证实 ,用荧光物质 DPH标记突触体后测定荧光强度 ,后者反映突触体膜流动性。结果 :　实验第 2 w FD血清叶酸浓度降低 (P<0 .0 1 )。FD及 PF第 6 w时 SFA浓度明显低于 AL和 PF(P<0 .0 1 ) ,平均逃避潜伏期明显延长 ,原平台象限游泳距离百分比及海马组织突触体膜流动性均明显下降。与对照组比较 ,对饲组上述指标的改变不明显 (P>0 .0 5 )。相关分析结果 :海马结构分离突触体膜 r值与血清叶酸浓度、平均逃避潜伏期及原平台象限游泳距离百分比显著相关 (r=- 0 .5 2 7,P<0 .0 5 ;r=- 0 .45 1 ,P<0 .0 5 ;r=- 0 .5 79,P<0 .0 5 )。结论 :　 1 .叶酸缺乏可损害离乳大鼠的空间学习记忆能力和降低海马突触体膜?Objective: The relationship of hippocampal synaptosomal membrane fluidity and the effect of the folate deficiency on weanling rats' learning and memory was studied. Methods: 54 male weanling Sprague-Dawley rats were divided into three groups. The folate deficient group received an amino acid-defined diet(RHAA), the ad libitum control group had the same diet supplemented with 8 mg folate per kg diet, and the pair-fed control group received the folate supplemented diet, but was individually pair-fed to the folate deficient group. At the end of the 2nd and 6th week of the experiment, 27 rats,9 from each, were trained for Morris Water Maze behavioral test for 5 days, An auto-video system recorded the escape latency and the swimming pattern. The serum folate concentration and the fluorescence intensity of the hippocampal synaptosomal membrane(r value) marked by a fluorescent substance DPH, which reflected the membrane fluidity, were also assayed . Correlation analysis was proceeded among serum folate concentration and fluorescence intensity and the percentage of swimming distance in the platform quadrant. Results: Decreased serum folate occurred at the end of the 2nd week of the experiment, without alteration of the other parameters. At the end of the 6th week, FD group rats had very low serum folate concentration (P<0.01), with the mean escape latency lengthened and the percentage of swimming distance in the platform quadrant decreased. The fluorescence intensity of the hippocampal synaptosomal membrane increased, which implied reduced membrane fluidity (P<0.01). Correlation analysis results showed that the fluorescence intensity of the hippocampal synaptosomal membrane(r value)and the serum folate concentration, mean escape latency and the percentage of swimming distance in the platform quadrant were highly correlated(r=-0.527, P<0.05; r=-0.451, P<0.05; r=-0.579, P<0.05). Conclusion: 1. Folate deficiency can impair learning and memory of weanling rats and can reduce the hippocampal synaptosomal membrane fluidity. 2

关 键 词：叶酸缺乏 学习记忆 突触体膜流动性 离乳大鼠 

分 类 号：R591.424[医药卫生—内科学]