中文摘要：

目的 探讨慢性铝暴露对大鼠学习记忆能力及脑源性神经生长因子的影响.方法 32只雄性SD大鼠按照体重随机分为4组,每组8只,染毒组分为高、中、低3个剂量组（120.0、12.0、1.2mg/kg）,染毒组将AlCl3混入饲料中喂养,对照组每日正常饲养.喂饲6个月后采用电感耦合等离子质谱法测定脑铝含量,Morris水迷宫检测大鼠的认知功能,免疫印迹法和ELISA法检测脑组织脑源性神经生长因子.结果 高、中剂量组大鼠脑组织铝含量高于对照组,差异有统计学意义（P＜0.05）；Morris水迷宫试验中,高、中剂量组寻找平台的潜伏期较对照组延长,差异有统计学意义（P＜0.05）,第1次到达目标区域的时间与对照组相比明显延长,差异有统计学意义（P＜0.01）,穿越平台次数与目标象限停留时间与对照组相比明显减少,差异有统计学意义（P＜0.05）；免疫印迹和ELISA法结果显示,随着染铝剂量的增加,大鼠脑组织脑源性神经生长因子的表达和含量降低,高、中剂量组明显低于对照组,差异有统计学意义（P＜0.05）.结论 在本研究所采用的中、高剂量（12.0,120.0 mg/kg）铝暴露下可以导致大鼠脑组织脑源性神经生长因子表达明显降低,这可能是引起学习记忆受损的机制之一.

英文摘要：

Objective To investigate the effects of chronic aluminum exposure on the learning and memory abilities and brain-derived nerve growth factor （BDNF） in Sprague-Dawley （SD） rats.Methods Thirty-two male SD rats were randomly and equally divided into 4 groups：control group and high-,middle-,and low-dose exposure groups.The rats in high-,middle-,and low-dose exposure groups were fed with the feed mixed with AlCl3 （120.0,12.0,and 1.2 mg/kg,respectively）,while the rats in control group were fed conventionally.After 6 months of feeding,brain aluminum levels were determined by inductively coupled plasma mass spectrometry; Morris water maze was employed to test the learning and memory abilities; the expression and content of BDNF in brain tissue were measured by Western blot and enzyme-linked immunosorbent assay （ELISA）.Results The high-and middle-dose exposure groups had significantly higher brain aluminum levels than the control group （P＜0.05）.The Morris water maze test showed that the high-and middledose exposure groups had significantly prolonged escape latency （P＜0.05）,significantly prolonged time taken to first reach the target quadrant （P＜0.01）,and significantly decreased number of platform crossings and time spent in the target quadrant （P＜0.05）,as compared with the control group.The Western blot and ELISA showed that the expression and content of BDNF in brain tissue decreased as the dose of AlCl3 increased,and they were significantly lower in the high-and middle-dose exposure groups than in the control group （P＜0.05）.Conclusion Chronic aluminum exposure （12.0 and 120.0 mg/kg） can lead to cognitive dysfunction in rats,and the decreased expression of BDNF may be one of the mechanisms of learning and memory deficits induced by aluminum.