PAS-Na对染锰大鼠学习记忆及海马神经微丝蛋白表达的影响

目的]探讨对氨基水杨酸钠（PAS．Na）对染锰大鼠学习记忆功能及神经微丝蛋白（NF）表达的影响。方法]将48只雄性sD大鼠随机分为对照组、染锰组、PAS—Na低、高剂量治疗组（L—PAS、H．PAS）四组，染锰组、L-PAS组、H—PAS组大鼠每日腹腔注射（ip）氯化锰（MnCl2·4H2O，15mg／kg），每周5d，共3周。然后，L-PAS、H—PAS组大鼠每日分别于背部皮下注射（sc）PATS．Na100mg／kg、200mg／kg，持续5周。采用Morris水迷宫检测大鼠学习记忆能力，免疫组织化学方法检测海马齿状回颗粒细胞下层微丝蛋白（NF）阳性细胞数。结果]染锰组逃避潜伏期、游泳总路程均比正常对照组长（P〈0．05）；H．PAS组逃避潜伏期和游泳总路程比染锰组缩短（P〈0．05）。染锰组NF阳性细胞数比正常对照组减少（P〈0．01），H．PAS组NF阳性细胞数较染锰组增多（P〈0．01），但是仍达不到正常对照组水平（P〈0．01）。结论]高剂量PAS—Na对锰致学习记忆能力及海马颗粒细胞受损可能有作用。

Effects of Sodium Para-aminosalicylic Acid on Learning,Memory and Neurofilament Expression in Hippocampus of Manganese-exposed Rats

Objective ] To explore the effects of sodium para-aminosalicylic acid on learning, memory and expression of nurofilament in hippoeampus of manganese-exposed rats. Methods ] Forty-eight male Sprague-Dawley rats were randomly divided into the control, manganese-exposed, L-PAS and H-PAS groups. The rats were intraperitoneally given manganese chloride （MnC12-4H20 15 mg/kg ）daily for 3 weeks （5 days/week ）and treated with PAS-Na at 100 or 200 mg/kg by subcutaneous injection on back in the following 5 weeks （ 7 days/week ）. The ability of learning and memory was tested by Morris Water Maze （ MWM ）and the expression of neurofilament protein in hippocampal subgranular zone of dentate gyms was examined by immunohistochemical technique. Results ] The escape latency and swimming distance were obviously prolonged in the manganese-exposed group as compared with that of the control group（ P〈0.05 ）. The escape latency and swimming distance of the rats in the H-PAS group were significantly shorter than that in the manganese-exposed group （ P 〈 0.05 ）. NF positive cells in the manganese-exposed group were distinctly less than that in the control group, and the number of NF was evidently incereased in the H-PAS group, but still not recovered to the level of control group （ P〈0.01）. Conclusion ] H-PAS may be an antagonist to manganese exposure by showing reduce the adverse effects on learning, memory and neurons in hippocampal subgranular zone of dentate gyms in the manganese-exposed rats.