双酚A暴露对成年小鼠焦虑行为的影响

Effects of BPA exposure on anxiety-like behavior in adult mice

为研究双酚A（bisphenol-A,BPA）暴露可能对成年小鼠神经行为的影响,将成年小鼠暴露于BPA（0.04,0.4,4和40 mg/（kg·d）12周后,发现BPA（0.04～4 mg/（kg·d））可降低雄鼠血清和脑内的睾酮水平,但对雌鼠血清和脑内的雌二醇水平没有影响.旷场、明暗箱、镜子迷宫和高架十字迷宫等行为模型的检测结果显示,BPA暴露12周对小鼠的活动性和探究意愿没有显著影响,但明显增加雌鼠却减少雄鼠在高架十字迷宫中进入开放臂的次数和开放臂停留时间,表明成年期BPA暴露可加剧雄鼠而减轻雌鼠的焦虑情绪.这些结果提示,长期BPA暴露可性别特异性地影响成年小鼠的焦虑状态,脑内性激素水平的改变可能与此有关.

Bisphenol-A（ BPA）,an environmental endocrine disruptor,attracted attention because of its adverse effects on the brain and behavioral development. Previous evidence indicated that perinatal exposure to low levels of BPA affected anxiety- and depression-like behaviors in adult rodents. Because sex hormones played a critical role in neurobehavior in adulthood,it seemed possible that exposure to BPA would have widespread effects on these emotional behaviors in adulthood. In the present study,anxiety- and depression-like behaviors were tested after exposure the adult mice to BPA（ 0. 04,0. 4,4,40 mg /（ kg·d）） for 12 weeks by open field,elevated plus maze,light-dark transition task and mirrored maze. The results showed that,BPA reduced the number of open arm entries and the time spent in open arms in the elevated plus maze of males but increased those of females. These results suggested a BPA-induced enhancement of anxiety-like behavior in males and an anxiolytic effect of BPA in females. Furthermore,BPA（ 0. 04 ～ 4 mg /（ kg·d）） significantly decreased serum and brain levels of testosterone in males,but no significant influence was found in serum and brain levels of estradiol in females. These results suggested that long-term exposure to BPA affected anxietylike behavior in adult mice,and which might be generated by hormone levels changing.