钙对出生前后低水平铅暴露大鼠学习记忆的影响

目的:观察钙对出生前后低水平铅暴露大鼠学习记忆的影响,探讨低铅暴露早期干预的有效手段.方法:将成年Wistar孕大鼠随机分为正常组、染铅对照组和染铅加钙组,自母鼠孕15 d至幼鼠7 w龄各组喂以相应饲料和饮水.实验大鼠4 w龄时进行跳台试验,6 w龄时进行Y迷宫试验,7 w龄时检测全血铅、血清钙含量以及大脑、海马重量.结果:实验大鼠血铅含量染铅对照组最高,染铅加钙组次之,正常组最低,血清钙含量正常组与染铅加钙组均高于染铅对照组;学习记忆成绩染铅加钙组好于染铅对照组,但低于正常组;实验未发现低铅染毒对实验大鼠大脑、海马重量的影响.结论:低铅暴露尚不足以引起机体器官组织重量的改变,但生理功能已明显受到伤害,增加钙补充可明显改善铅暴露大鼠的学习和记忆能力,同时降低血铅含量.

Effects of calcium on ability of learning and memory in rats exposed to low level lead before and after birth

Objective: To investigate the effects of calcium on learning and memory ability of rats exposed to low level lead before and after birth. Methods: Wistar dam rats were randomly divided into normal group,lead-conta-minated group and lead with Ca group. Corresponding food and water were given to pregnant rats from d15 of gestation and to young rats till 7 w after birth. The weight of brain and hippocampus,blood lead content,serum cal-(cium) content,learning and memory ability of young rats were tested. Results: The blood lead concentrations: lead-contaminated group was the highest,lead with Ca group the second and normal group the lowest. Serum calcium concentrations: normal group and lead with Ca group were both higher than lead-contaminated group. Ability of learning and memory: lead with Ca group was better than lead-contaminated group,but poorer than normal group. No differences were found upon the weight of brain and hippocampus in all groups. Conclusion: The exposure to low-level lead may not change the weight of brain or hippocampus,but affect the ability of learning and memory of young rats. Supplement of calcium in food and water may reduce the blood lead levels and improve learning and memory ability of rats.