大鼠脑铅和血铅含量对学习记忆的影响与硒锌的保护作用

目的　探讨食物铅进入机体后对记忆功能的影响以及补充锌和硒对铅致损伤的保护作用。方法　将Wistar大鼠按体重随机分为 10组 ,在基础饲料里分别添加不同剂量的亚硒酸钠、乳酸锌及醋酸铅 ,实验期为 12周。结果　染铅各组大鼠的脑和全血中铅含量均显著高于对照组。在染铅各组中 ,从低硒缺锌到高硒高锌组大鼠的脑铅含量呈下降趋势 ,对照组大鼠的脑铅含量未检出。染铅各组大鼠血铅含量也不同程度地受饲料中硒和锌水平的影响 ,硒和锌对降低脑铅含量有协同作用 (P <0 0 0 1)。各组大鼠发生错误次数和到达终点所需时间明显不同 ,缺锌低硒染铅组发生的错误次数和所需时间显著高于其他染铅各组和对照组(P <0 0 5 ) ;补硒可显著改善染铅大鼠水迷宫实验所需时间和降低错误次数 (P =0 0 0 2和P =0 0 0 7)。大鼠水迷宫试验中随着脑铅和血铅含量的增加 ,到达终点所需时间延长和发生的错误次数增加。结论　良好的锌和硒营养状况有助于降低组织中铅的水平 ,提示可能具有拮抗铅毒性的作用

Protection of zinc and selenium content of brain and blood on learning and memory exposed to lead in growing rats

Objective The purpose of this paper was to explore the relations between lead levels of brain and blood on learning and memory, and to determine the antagonization of selenium and zinc on lead toxicity in brain and blood. Methods The growing rats were fed with diet added with different levels of selenium, zinc and lead for 12 weeks. Results (1) The lead levels of brain and blood of rats exposed to lead was higher than that of the control group; the lead levels of brain and blood administrated lead decreased following the increased in selenium and zinc levels in the diet. (2)Error frequencies and total time in water maze significantly reduced in the groups exposed to lead. (3)Error frequencies and total time in water maze and lead levels of brain and blood presented positive relation. Conclusion The present study indicated that supplementary suitable zinc or/and selenium could alleviate the lead toxicity on the brain and blood of rats.