铅对仔鼠学习记忆及其海马中突触体相关蛋白-25基因和蛋白表达的影响  

Lead impairs ability of learning and memory and affects expression of synaptosomal-associated protein-25 in hippocampus of offspring

作　　者：李宁[1] 贾金霞[1] 郑艳涛[1] 刘欣欣[1] 朱明君[1] 时宝庆[1] 李文杰[1] 

机构地区：[1]郑州大学公共卫生学院,450052

出　　处：《中华劳动卫生职业病杂志》2010年第9期652-655,共4页Chinese Journal of Industrial Hygiene and Occupational Diseases

基　　金：高校博士点专项科研基金资助（20070459010）

摘　　要：目的 探讨母体铅染毒对仔鼠学习记忆及海马中突触体相关蛋白-25（SNAP-25）mRNA 表达的影响.方法 雌性小鼠自妊娠第1天开始经饮水染铅（0.3、1.0、3.0g/L）,对照组饮蒸馏水,至仔鼠出生后21 d断乳为止.随机抽取各组仔鼠,在出生后第7、14、21天分别测其血液和海马组织中铅的含量;在出生后第21天时,进行水迷宫试验,分别采用反转录-聚合酶链反应和免疫组化方法测定各组海马组织中SNAP-25 mRNA和蛋白的表达.结果 与对照组比较,各剂量染铅组血液、海马组织中铅含量均明显升高,差异均有统计学意义（P〈0.05）.仔鼠错误次数有随母鼠染铅剂量增加而增加的趋势,1.0、3.0g/L组错误次数分别为5.89±0.54、9.53±1.03,与对照组（1.73±0.07）比较,差异有统计学意义（P〈0.05,P〈0.01）.与对照组相比,染铅组海马中SNAP-25 mRNA和蛋白表达明显降低,差异均有统计学意义（P〈0.05）.结论 母体铅暴露可导致仔鼠学习记忆功能损害,铅下调SNAP-25 mRNA的表达,可能影响了突触前末梢神经递质的释放,造成神经系统的损害.Objective To find the effects of lead taken by pregnant mice on learning and memory and the expression of synaptosomal-associated protein（SNAP）-25 Mrna and protein, in order to reveal the mechanism of neurotoxicity induced by lead. Methods Lead exposure was conducted through freely drinking the corresponding lead acetate solutions with dosages of 0.3, 1.0, 3.0 g/L respectively. Each group was composed of 10 mice. 7, 14 and 21 days after their birth. The lead contents in blood and hippocampus of the offspring were determined. At the 21st day the expression of SNAP-25 Mrna and protein in hippocampus of all the offspring in various dosages groups were determined by RT-PCR and immunohistochemistry assay. Results The lead contents in blood and hippocampus of various lead exposed groups were significantly higher than those of the control group（P〈0.05 ）. The lead levels in blood and hippocampus changed accordingly to the days of growth. In Water Morris Maze experiment, the result of 0.3 g/L group was not significantly different from that of the control group （P〉0.05）, however, the results of 1.0, 3.0 g/L groups （5.89±0.54,9.53± 1.03 ） were significantly different from those of the control group （ 1.73±0.07 ） （P〈0.05 ,P〈0.01 ）. The expression of SNAP-25mRNA and protein was lower in lead exposed groups than that of the control group （P〈0.05）. Conclusion Maternal lead exposure may induce the damage in the ability of learning and memory of the offspring. The neurotoxicity of lead may be induced by decreasing the expression of SNAP-25 Mrna and protein so as to affect the release of neurotransmitter from presynaptic terminal resulted in nerve damages.

关 键 词：铅 基因 突触体 迷宫学习 记忆 

分 类 号：R686[医药卫生—骨科学]