【摘要】 目的研究褪黑素(MT)对Alzheimer病(AD)模型大鼠认知功能和海马tau蛋白过度磷酸化的影响。方法给大鼠海马内注射凝聚态β-淀粉样蛋白(Aβ)25-35制作AD模型;MT组大鼠从制模前7d至制模后19d每日腹腔注射MT,AD组大鼠制模后腹腔注射生理盐水;用Morris水迷宫试验检测大鼠的认知功能,银染法观察海马神经元形态,免疫组化法观察过度磷酸化tau蛋白的表达,并与正常对照组比较。结果MT组大鼠Morris水迷宫试验结果明显好于AD组(均P<0.001);海马CA1区磷酸化tau蛋白阳性细胞数(60.0±2.3)明显少于AD组(98.4±3.0)(P<0.001),与正常对照组比较差异无统计学意义;海马CA1区神经元纤维形态较AD组规则。结论MT可明显改善AD大鼠的认知功能,并且抑制海马tau蛋白的过度磷酸化。更多还原

【Abstract】 Objective To sdudy the effects of Melatonin(MT)on cognition and tau hyperphosphorylation in hippocampus of Alzheimer’s disease(AD)model rats.Methods Aβ25-35 was injected into the hippocampus to make AD model rat.MT was injected intraperitoneully into rats of MT group 7 days before and 19 days after modeling.Normal saline(NS)was injected intraperitoneully into rats of AD group after modeling.The cognition was tested by Morris water maze.The pathological changes of hippocampus was observed by Bielschowsky staining and the tau hyperphosphorylation was detected by immunohistochemistry staining.The results were compared with normal control group.Results In MT group,the results of Morris water maze were significant better than those in AD group(all P<0.001);and the amount of P-tau positive cells(60.0±2.3)was remarkable decrease than that in AD group(98.4±3.0)(P<0.001);but there was no difference between MT group and normal control group.The neurofibrils in hippocampus of MT group were more regular than that in AD group.Conclusions MT improves cognition of AD-rats and inhibits hyperphosphorylation of tau in hippocampus.更多还原