中文摘要：

目的 探讨母鼠纳米铅暴露对出生后21天（PND21）和PND42仔鼠学习记忆以及大脑铁稳态的影响.方法 成年雌性SD孕鼠20只,随机分为对照组和暴露组.暴露组大鼠经口给予10 mg/kg纳米铅,对照组大鼠给予等量的生理盐水.仔鼠离乳后继续暴露相应剂量的纳米铅直至出生后42天.应用Morris水迷宫测试PND21和PND42仔鼠学习与记忆功能;获取PND21和PND42仔鼠海马和皮质,应用电感耦合等离子质谱（ICP-MS）法测定海马和皮质铅和铁含量.Perl＇s铁染色观察海马和皮质铅铁分布,酶联免疫吸附法（ELASA）检测海马和皮质中铁蛋白、膜铁转运蛋白（FPN1）、膜铁转运辅助蛋白（HP）、铜蓝蛋白（CP）的表达.结果 纳米铅暴露后,PND21和PND42仔鼠皮质中铁的含量分别为（32.63±6.03）和（46.20± 10.60） μg/g,高于对照组（27.04±5.82）和（36.61±10.23） μg/g,差异均有统计学意义（P＜0.05）;PND42仔鼠海马组织中铁含量为（56.92±4.37） μg/g,高于对照组（37.71±6.92） μg/g,差异有统计学意义（P＜0.05）;Perl＇s染色结果显示,暴露组皮质、海马均有大量铁沉积;纳米铅暴露组PND21仔鼠皮质FPN1含量为（3.64±0.23） ng/g,低于相应对照组（4.99±0.95） ng/g,差异有统计学意义（P＜0.05）;纳米铅暴露组PND42仔鼠海马FPN1含量为（2.28±0.51） ng/g,低于相应对照组（3.69±0.69） ng/g,差异有统计学意义（P＜0.05）.与对照组相比,暴露组PND21和PND42仔鼠逃逸潜伏期延长,分别为（15.54±2.89）和（6.16±1.42）s,高于相应对照组（9.01±4.66）和（4.26±1.51）s;穿越平台次数下降,分别为（7.77±2.16）和（8.12±1.51）次,低于相应对照组（11.27±1.61）和（13.00±2.21）次,差异有统计学意义（P＜0.05）.结论 纳米铅暴露可引起仔鼠海马和皮质中的铁稳态失调,并影响仔鼠学习记忆能力.

英文摘要：

Objective To investigate the effects of nano-lead exposure on learning and memory and iron homeostasis in the brain of the offspring rats on postnatal day 21 （PND21） and postnatal day 42 （PND42）.Methods Twenty adult pregnant female Sprague-Dawley rats were randomly divided into control group and nano-lead group.Rats in the nano-lead group were orally administrated 10 mg/kg nano-lead,while rats in the control group were administrated an equal volume of normal saline until PND21.On PND21,the offspring rats were weaned and given the same treatment as the pregnant rats until 42 days after birth.The learning and memory ability of offspring rats on PND21 and PND42 was evaluated by Morris water maze test.The hippocampus and cortex samples of offspring rats on PND21 and PND42 were collected to determine iron and lead levels in the hippocampus and cortex by inductively coupled plasma-mass spectrometry.The distributions of iron in the hippocampus and cortex were observed by Perl＇s iron staining.The expression levels of ferritin,ferroportin 1 （FPN 1）,hephaestin （HP）,and ceruloplasmin （CP） were measured by enzyme-linked immunosorbent assay.Results After nano-lead exposure,the iron content in the cortex of offspring rats on PND21 and PND42 in the nano-lead group was significantly higher than those in the control group （32.63±6.03 μg/g vs 27.04±5.82 μg/g,P〈0.05;46.20±10.60 μg/g vs 36.61 ±10.23 μg/g,P〈0.05）.The iron content in the hippocampus of offspring rats on PND42 in the nano-lead group was significantly higher than that in the control group （56.92± 4.37 μg/g vs 37.71 ±6.92 μg/g,P〈0.05）.The Perl＇s staining showed massive iron deposition in the cortex and hippocampus in the nano-lead group.FPN1 level in the cortex of offspring rats on PND21 in the nano-lead group was significantly lower than that in the control group （3.64±0.23 ng/g vs 4.99±0.95 ng/g,P〈0.05）.FPN1 level in the hippocampus of offspring rats on PND42 in the nano-lead group was significantly lower than t