围生期喂饲母鼠磺胺二甲嘧啶对F1代仔鼠空间辨别能力和大脑ChAT活性的影响

Effect of Perinatal Feeding Sulphamethazine on Spatial Learning and ChAT Activity in Brain of Rats

[目的 ]了解妊娠中晚期和哺乳期母体接触磺胺二甲嘧啶对子代大鼠空间辨别能力及脑内胆碱乙酰转移酶(ChAT)活性的影响。 [方法 ]SD大鼠在受孕第 7天起至哺乳期结束分别每日给予磺胺二甲嘧啶 0、5 0、10 0和 2 0 0mg/kg ,用水迷宫实验检测各组 2 0～ 3 0日龄仔鼠的空间辨别能力 ,同时取 3 0日龄仔鼠的大脑进行免疫组化染色 ,观察脑内ChAT的表达。 [结果 ]染毒组仔鼠出现空间辨别能力障碍 ,尤其是 10 0、2 0 0mg/kg剂量组与对照组相比到达终点时间显著延长 ,错误次数显著增多 (P <0 .0 5 )。大脑的免疫组化分析发现 ,染毒组仔鼠大脑皮质和海马区ChAT的表达降低 ,尤其是10 0、2 0 0mg/kg剂量组与对照组相比差异有统计学意义 (P <0 .0 5 )。 [结论 ]给围生期母鼠喂饲磺胺二甲嘧啶可能通过降低大鼠体内的甲状腺素浓度 ,影响脑内ChAT的水平 。

Objective To study the effect of perinatal exposure to sulphamethazine on spatial learning and choline acetyltransferase(ChAT) activity in brain of rats. Dams were fed sulphamethazine 0,50,100 and 200 mg/kg per day respectively from gestational day 7 to postpartum day 21.The function of spatial learning of pups was measured by water maze test.Brain of pups of postnatal day 30 was used to observe ChAT expression by immunohistochemistry staining. Significant deficiency on spatial learning was observed in offsprings exposed to sulphamethazine in water maze test(P<0.05).The expression of ChAT significantly decreased in cerebral cortex and hippocampus of rats in the 100 and 200 mg/kg groups(P<0.05). [Conclusion] Perinatal exposure to sulphamethazine may affect the ChAT activity and spatial learning by disrupting thyroxine.