摘要
目的比较长期饮用纯净水和自来水对血脑铅蓄积以及铅神经毒性的差异。方法断乳雄性SD大鼠104只，计算机编程完全随机化实验设计分为4对8组，饮水分别为自来水、纯净水、自来水含铅（醋酸铅）50mg／L、纯净水含铅50mg／L、自来水含铅200mg／L、纯净水含铅200mg／L、自来水含铅800mg／L、纯净水含铅800mg／L。各组食物及其他处理因素完全一致。分别在12、24周时对大鼠进行Morris水迷宫实验中的定向航行、空间探索和可视平台实验。28周时处死大鼠取材，采用原子吸收分光一石墨炉法测定血铅和脑铅，采用RT—PCR法检测海马NMDA受体NR1、NR2A和NR2B亚基mRNA的表达。结果铅染毒剂量相同时，不同的饮水对大鼠血铅的影响未显示差异，但饮用纯净水的大鼠脑铅均高于饮用自来水的大鼠，其中对照组及高铅组的增高差异具有统计学意义；饮用纯净水的大鼠其NR1、NR2A、NR2B亚基mRNA的表达均低于饮用自来水的大鼠，其中低铅组的NR2A亚基表达差异具有统计学意义；24周水迷宫实验中，饮用纯净水的大鼠其定向航行实验的逃逸潜伏期长于自来水组，其中低、中铅剂量组差异都具有统计学意义，且差异来自于实验的前2d。结论与饮用自来水相比较，长期饮用纯净水可增加大鼠脑组织铅蓄积，降低NMDA受体NR1，NR2A，NR2B亚基mRNA的表达，同时迟滞其空间学习记忆能力。低剂量铅暴露下上述效应更为明显。
Objective To compare brain lead accumulation and neurotoxicity induced by lead under drinking purified water and tap water on rat. Methods All 104 male weaning SD rats were randomly divided into eight groups, matched-four pairs according to drinking water： tap water, purified water, tap water with lead 50 mg/L（ lead acetate water-solution） , purified water with lead 50 mg/L, tap water with lead 200 mg/L, purified water with lead 200 mg/L, tap water with lead 800 mg/L All were fed with normal food and environmental cognitions kept consistent. Morris water maze（ including Place Navigation, Spatial Probe Test, Visible Platform Trial） was measured to test rat spatial learning at the 12 and 24 week. At the end of the experiment （28 week） , rats were killed and the lead of brain and blood was measured by Graphite furnace atomic absorption spectrometric method; the NR1, NR2A, NR2B of NMDAR （N-methyl-D-aspartame receptor） in hippocampus were analyzed by RT-PCR. Results Under the same lead exposure, no significant differences were observed in blood lead, however, brain lead level showed higher in drinking purified water group than that in tap water group. Expression of NR1 ,NR2A and NR2B in hippocampus of the rats drinking purified water was lower than those drinking tap water, especially at low lead exposure （50 mg/L） （P 〈 0.05）. In the 24 week Morris water maze, place navigation test＇s escape latency showed significantly prolonged at the rats drinking purified water as compared with those drinking tap water on the pairs of 50 mg/ L and 200 mg/L pb^2＋ groups （ P 〈 0. 05 ）, and the differences occurred in early 1-2 days. Conclusion Compared with drinking tap water, drinking purified water might increase the accumulation of brain lead, lower NR1 ,NR2A,NR2B expression and delay the spatial learning and memory ability under chronic lead exposure in water.
出处
《中华预防医学杂志》
CAS
CSCD
北大核心
2008年第6期431-436,共6页
Chinese Journal of Preventive Medicine
基金
国家自然科学基金（59838300）
