锌对染铅大鼠海马一氧化氮合酶的保护作用(英文)  

Protection of zinc on hippocampal nitric oxide synthase in lead-exposed rats

作　　者：闫蓓[1] 李积胜[1] 刘亚华[1] 杨烽[1] 

机构地区：[1]武警医学院军事预防医学研究所,天津300162

出　　处：《武警医学院学报》2005年第3期157-161,共5页Acta Academiae Medicinae CPAPF

基　　金：国家自然科学基金项目(39870689)

摘　　要：【目的】探讨铅对海马长时程增强(LTP)的影响与海马不同亚区一氧化氮合酶(NOS)变化的关系以及锌的拮抗作用。【方法】采用反映学习记忆功能的Y迷宫法测试大鼠神经行为的改变;用NADPH黄递酶(NADPH d)组化法和神经元型NOS(nNOS)的免疫组化法研究大鼠海马不同亚区NOS的活性及表达情况。【结果】染铅组大鼠的学习记忆能力比铅锌组和对照组明显下降(P<0.05),铅锌组与对照组之间无差别;组化及免疫组化显示:染铅组大鼠海马CA1区和齿状回的NOS和nNOS阳性神经元明显少于铅锌组和对照组(P<0.05),在CA3区无差别,铅锌组与对照组各亚区均无差别。【结论】铅可损伤大鼠学习记忆能力,鉴于NOS参与LTP这一代表学习记忆的电生理指标的形成和维持,推测铅对学习记忆和海马LTP的影响可能与染铅后海马各区NOS的不同变化有关。锌对铅引起的学习记忆损伤和NOS的影响有拮抗作用。To investigate the relationship between the effects of lead on long term potentiation(LTP) in hippocampus and changes of nitric oxide synthase(NOS) in subfields of hippocampus, and the antagonistic role of zinc.Y-maze test was applied to study the effects of lead on learning and memory ability in rats; NADPH-d histochemistry and nNOS immunohischemistry were used to investigate the activity and protein expression of NOS in different hippocampal subfields in lead-exposed rat.Compared with the control and lead-zinc group, the learning and memory ability of lead-exposed rats was significantly decreased(P<0.05); the number of NOS positive neurons and neuronal nitric oxide synthase(nNOS) positive neurons in CA_1 and dentate gyrus of lead-exposed rats were significantly decreased(P<0.05), but no significant changes in CA_3; no difference was found between the control and lead-zinc groups in CA_1, CA_3 and dentate gyrus.[Conclusion]Lead may damage the learning-memory ability of the rats; the effects of lead on LTP in hippocampus might be related to the changes of NOS in different subfields of hippocampus in lead-exposed rats; zinc might play an important role in preventing lead-induced damages.

关 键 词：铅 锌 一氧化氮合酶 海马 

分 类 号：R151.2[医药卫生—营养与食品卫生学]