摘要目的 研究哺乳期母鼠接触氯氰菊酯对子代成年雌鼠学习记忆能力的损害作用及其可能机制.方法 12只ICR母鼠随机分成对照组、6.25和25.00 mg/kg染毒组(每组4只母鼠,每窝10只仔鼠,雌雄各半,即每组20只雌鼠),于子代雌鼠出生后第1～21天(PNDl～ PND21),每天经口灌胃给予母鼠氯氰菊酯(6.25和25.00 mg/kg)染毒1次,对照组母鼠给予玉米油.染毒后39d,采用六臂放射状水迷 宫检测PND60雌鼠的学习记忆能力.检试结束后,称体重,处死动物取脑称重并分离海马组织,用蛋白质免疫印迹(Western blotting)法检测海马中N-甲基-D-门冬氨酸(NMDA)受体NR1亚单位蛋白表达水平.结果 各组子代雌鼠体重和脑重的差异无统计学意义(P＞0.05).经重复测量资料方差分析显示,在学习期,25.00 mg/kg染毒组子代雌鼠潜伏期[(31.3±17.0)s]长于对照组[(21.0±14.0)s]；在记忆期,25.00 mg/kg染毒组子代雌鼠潜伏期[(24.6±21.1)s]较对照组[(14.1±16.3)s]延长,差异均有统计学意义(P＜0.05).各组子代雌鼠在学习期和记忆期的错误数比较,差异均无统计学(P＞0.05).与对照组相比,25.0 mg/kg染毒组子代雌鼠海马组织NR1蛋白表达水平明显降低,差异有统计学意义(P＜0.01).结论 哺乳期母鼠接触氯氰菊酯在一定程度上损伤子代成年雌鼠学习记忆能力,可能与海马组织中NR1亚单位蛋白表达水平下降有关.

abstractsObjective To explore the effect of maternal cypermethrin exposure during lactation on learning and memory ability in adult female offspring,as well as the possible mechanism.Methods Twelve maternal mice were randomly divided into 6.25 mg/kg cypermethrin,25.0 mg/kg cypermethrin and control groups (four dams each group,ten pups each dam,half male half female,twenty female pups each group).Maternal mice were orally administered with different doses of cypermethrin (6.25 and 25 mg/kg/d) once daily from postnatal day 1 (PND1) to PND21.Maternal mice in control group were treated with corn oil.The learning and memory ability of female offspring were observed by using water labyrinth task for continuously seven days on PND60.All the female offspring were killed and the brain and hippocampus were detached after the test.The expression level of NMDA receptor NRl protein in hippocampus was detected by Western-blotting.Results There were no statistically significant in the difference in weight of body and brain among three groups (P＞ 0.05).Through the Repeated one way ANOVA,the learning time of latence in the 25.0 mg/kg cypermethrin group [(31.3±17.0) s]were significantly longer than that in the control group [(21.0±14.0) s](P＜0.05).The memory time of latence in the 25.0 mg/kg cypermethrin group[(24.6±21.1) s]were significantly longer than that in the control group [(14.1±16.3) s](P＜0.05).However,the difference of the wrong number among groups was not statistically significant in the test (P＞0.05).Conclusion Maternal cypermethrin exposure during lactation disturbs learning and memory ability in adult female offspring in a degree,which maybe caused by the reduction of protein level of hippocampus NR1.