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

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

[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)PAS-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。

[ 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.