中文摘要：

本文旨在探讨亚硝酸钠对大鼠海马Tau蛋白、神经细丝（neurofilament，NF）磷酸化水平及空间学习记忆的影响。大鼠饮用水中溶入亚硝酸钠粉剂，连续饮用60d（每天100mg／kg），通过Morris水迷宫检测大鼠的空间学习记忆能力，免疫印迹和免疫组织化学检测海马Tau和NF磷酸化水平与分布、蛋白磷酸酯酶2A（protein phosphatase 2A，PP2A）催化亚单位蛋白水平与分布。结果显示：与对照组相比，连续饮用亚硝酸钠的大鼠空间学习记忆能力下降（P〈0．05），Tau蛋白Ser396／404和Ser199／202位点及NF的磷酸化水平明显升高（P〈0．05），PP2A的催化亚单位蛋白水平下调（P〈0．05）。结果提示，亚硝酸钠可以导致大鼠空间学习记忆能力下降，PP2A催化亚单位蛋白水平下调，PP2A活性抑制及骨架蛋白发生过度磷酸化。

英文摘要：

The present study was aimed to explore the effect of sodium nitrite on cytoskeletal protein phosphorylation and spatial learning and memory in rats. Rats were served with drinking water containing sodium nitrite （100 mg/kg） for 60 days, then, the ability of spatial learning and memory of the rats was measured by Morris water maze. Phosphorylation level of tau and neurofilament, and the expression of protein phosphatase 2A （PP2A） catalytic subunit in the hippocampus were detected by immunohistochemistry and Western blot. In comparison with the rats served with normal tap water, the rats served with sodium nitrite water showed significantly longer latency to find the hidden platform in Morris water maze （P 〈 0.05）, elevated phosphorylation level oftau and neurofilament, and decreased expression of PP2A catalytic subunit （P 〈 0.05）. These results indicated that administration of sodium nitrite could impair the spatial learning and memory of the rats, and the hyperphosphorylation of cytoskeletal proteins and the down-regulation of PP2A might be underlying mechanisms for the impairment.