饮水砷暴露对大鼠血液和脑组织砷蓄积及学习与记忆能力的影响

Effect of Arsenic Exposure through Drinking Water on the Levels of Blood Arsenic and Brain Arsenic,Learning and Memory of Rats

目的研究饮水砷暴露对大鼠学习与记忆能力的影响。方法将48只雄性健康断乳 SD 大鼠随机分为4组,每组12只。对照组饮用自来水,砷暴露组分别饮用2.72、13.6和68 mg/L 亚砷酸钠溶液。饮水砷暴露12周后,用 Morris水迷宫检测大鼠的学习记忆能力,水迷宫实验完成后用氢化物发生-原子荧光光谱法测定大鼠血砷和脑砷含量。结果血砷含量随饮水砷浓度升高而升高,与对照组相比,差异有统计学意义(P<0.05)。脑砷含量随饮水砷浓度升高而升高,13.6mg/L 和68mg/L 组与对照组相比,差异有统计学意义(P<0.05)。在定向航行实验中,与对照组相比,68mg/L 组大鼠逃逸潜伏期显著延长(P<0.05)。在空间探索实验和可视平台实验中,各组间差异没有统计学意义。结论相对较高剂量的饮水砷暴露能降低大鼠的学习能力。

Objective To investigate the effect of arsenic exposure on learning and memory ability of rats. Methods Fourtyeight weaned SD rats were randomly divided into four groups,12 in each. The control group drank tap water, the other three groups treated with sodium arsenite at doses of 2.72 mg/L, 13.6 mg/L and 68 mg/L for 12 weeks. Morris water maze was used to test the spatial learning and memory ability of rats. Arsenic level in the blood and brain was assessed after Morris water maze test. Results Arsenic contents in the blood of arsenic exposed rats were significantly higher than that in control rats （P〈0.05）. Arsenic contents in the brain of 13.6 mg/L and 68 mg/L groups were significantly higher than that in control rats （P〈0.05）. In the place navigation, rats exposed to 68 mg/L solution of sodium arsenite needed longer time to find the hidden platform （P〈0.05）. There were no significant differences among the four groups in spatial probe test and visible platform trial. Conclusion Arsenic exposure can damage the spatial learning ability in rats, but this damage did not correlate with content of arsenic in the brain.