孕期和哺乳期双酚A暴露对雄性子代小鼠学习记忆能力的影响

Effect of Bisphenol A Exposure during Pregnancy and Lactation on Learning and Memory Ability in Male Mice Offspring

目的探讨孕期和哺乳期双酚A(BPA)暴露对子代雄性小鼠学习记忆能力的影响。方法将妊娠母鼠随机分成对照组(0.1%无水乙醇)、低剂量BPA组(0.2 mg/L BPA)和高剂量BPA组(2 mg/L BPA),每组8只,单笼饲养。妊娠第6天至哺乳期结束,自由饮水方式进行染毒。采用Morris水迷宫实验对断乳后4周龄子代雄鼠进行学习记忆行为检测,Western blotting检测子代雄鼠海马组织中雌激素受体α蛋白表达情况。结果与对照组比较,低剂量BPA组雄性仔鼠搜索平台的距离在训练第4、5天时显著延长(均P<0.05),而搜索平台的时间在训练第5天时显著延长(P<0.05)。与对照组比较,高剂量BPA组雄性仔鼠搜索平台的距离和时间在训练第4、5天时显著延长(均P<0.05)。与对照组比较,BPA组雄性仔鼠在测试时穿过目标象限的次数和在目标象限的停留时间均显著缩短(P<0.05)。与对照组比较,BPA组雄性仔鼠海马中雌激素受体α蛋白表达水平下降(P<0.05)。结论孕期和哺乳期暴露BPA能够损伤雄性仔鼠的学习和记忆能力,这可能与海马内雌激素受体α表达下降有关。

Objective To explore the effect of exposure to bisphenol A(BPA)during pregnancy and lactation on learning and memory abilities in male mice offspring.Methods Pregnant mice were randomly divided into three groups,with eight in each group.Two groups were exposed to a low dose(0.2 mg/L)or a high dose(2 mg/L)of BPA in drinking water from gestational day 6 to the end of lactation,and the control group received 0.1%of anhydrous alcohol with water in their drinking water.The Morris water maze was used to test learning and memory abilities in male offspring.ERαprotein expression in the hippocampus was determined by Western blotting.Results The results showed that the distance travelled was significantly longer on the fourth and fifth day than in controls(P<0.05),and the escape latency time was significantly longer on the fifth day in the low dose group than in controls(P<0.05).The escape latency time and distance travelled in the high dose group were significantly longer than those in the control group on the fourth and fifth day of training(P<0.05).The frequency and time spent in target quadrants were significantly shorter in BPA exposure groups than in controls(P<0.05).The levels of ERαprotein expression were significantly lower in BPA exposure groups than in controls(P<0.05).Conclusion Exposure of BPA during pregnancy and lactation can affect learning and memory ability in male offspring,which might be associated with downregulated ERαprotein expression.