摘要
目的探讨宫内暴露甲基汞对子代大鼠神经行为发育、学习记忆及海马区叉头框P2(FOXP2)表达的影响。方法将24只妊娠SD大鼠随机分为对照组(生理盐水)、0.6、1.2、2.4 mg/kg甲基汞染毒组,从受孕当天灌胃染毒至分娩,共染毒21 d;检测母鼠血液、小脑、肾脏等总汞含量;观察仔鼠神经行为发育情况;采用Morris水迷宫、穿梭实验检测仔鼠学习记忆能力;以免疫组化法检测仔鼠海马FOXP2蛋白表达情况。结果各剂量染毒组母鼠各脏器总汞含量均高于对照组,且各脏器总汞含量与血总汞含量呈正相关(P<0.05)。随染毒剂量的增加,仔鼠身长、体重均降低(均P<0.05)。各染毒剂量组仔鼠平面翻正反射时间、负趋地性反射时间均长于对照组。2.4 mg/kg剂量染毒组仔鼠定位航行潜伏期[M(P25~P75):58.10(32.89~101.36)s]长于对照组[M(P25~P75):19.29(11.95~26.19)s],差异有统计学意义(P<0.05);各剂量染毒组穿台时间较对照组延长(均P<0.05),2.4 mg/kg剂量染毒组穿台次数明显少于对照组(P<0.05);与对照组相比,2.4 mg/kg剂量染毒组穿梭实验正确次数降低,错误次数增加(均P<0.05)。免疫组化结果显示,各剂量染毒组海马组织FOXP2蛋白表达组间差异有统计学意义(F=11.24,P<0.05);与对照组相比,1.2、2.4 mg/kg剂量染毒组仔鼠FOXP2蛋白表达水平升高,差异均有统计学意义(均P<0.05)。结论宫内甲基汞暴露可抑制仔鼠神经行为发育、学习记忆能力,仔鼠海马组织FOXP2蛋白可能是甲基汞致神经损伤的分子靶点。
Objective To preliminarily explore the effects of intrauterine exposure to methylmercury on the neurobehavioral development,learning and memory and FOXP2 expression in hippocampus among offspring rats.Methods A total of 24 pregnent SD rats were randomly divided into control group(normal saline),0.6,1.2,2.4 mg/kg methylmercury exposure groups,and were given by gavage from the day of conception to delivery for a total of 21 days;The total mercury content in blood,cerebellum,and kidney of the female rats were determined,the neurobehavioral development of the offspring were measured;Morris water maze and shuttle-box test were used to detect the learning and memory ability of offspring;Immunohistochemical method was used to detect the expression of FOXP2 protein in the hippocampus of offspring.Results Compared with the control group,the total mercury content of each observed organ in exposure groups were higher,which was positively correlated with the total mercury content in blood(P<0.05).With the increase of the exposure doses,the body length and weight of offspring both were reduced(all P<0.05).The plane-righting reflex time and the extension time of negative geotaxis of offspring in each exposure dose group were longer than those in the control group.The incubation period of positioning navigation among offspring in 2.4 mg/kg methylmercury exposure group[M(P25-P75):58.10(32.89-101.36)s]was significantly higher compared with the control group[M(P25-P75):19.29(11.95-26.19)s],the difference was statistically significant;The periods of crossing the platform of offspring in each exposure group were longer than the control group(P<0.05),the times of crossing the platform of offspring in 2.4 mg/kg methylmercury exposure group was significantly less than that of the control group(P<0.05);Less number of avoidances and more number of non-responses in shuttle-box test were observed in 2.4 mg/kg methylmercury exposure group compared with the control group(P<0.05).Based on immuno-histochemical staining,FOXP2 protein expression in the hippocampus of offspring revealed significant difference among methylmercury exposure groups(F=11.24,P<0.05);Compared with the control group,the expression levels of FOXP2 protein in the hippocampus of offspring in 1.2 and 2.4 mg/kg methylmercury exposure groups increased with statistically significant difference(all P<0.05).Conclusion Intrauterine exposure to methylmercury can inhibit the neurobehavioral development and the ability of learning and memory of offspring,FOXP2 protein in the hippocampal of offspring may be a key molecular target of methylmercury-induced nerve injury.
作者
邓彩云
孙宝飞
黎健
王雪
张爱华
王文娟
DENG Cai-yun;SUN Bao-fei;LI Jian;WANG Xue;ZHANG Ai-hua;WANG Wen-juan(Environmental Pollution and Disease Monitoring Key Laboratory of Ministry of Education,Guizhou Medical University,Guizhou,Guiyang 550025,China;不详)
出处
《环境与健康杂志》
CAS
北大核心
2020年第7期585-589,共5页
Journal of Environment and Health
基金
国家自然科学基金(81703191,U1812403,81760573)
黔科合LH字[2016]7352
关键词
甲基汞
宫内暴露
大鼠
仔鼠
神经行为
学习记忆
FOXP2
Methylmercury
Intrauterine exposure
Offspring rats
Neurobehavior
Learning and memory
FOXP2
