中文摘要：

目的探讨黄芪多糖（APS）对阿尔茨海默病（AD）大鼠海马超微结构和低密度脂蛋白受体相关蛋白1（LRP1）水平的影响。方法 Wistar大鼠随机分成对照组,模型组,治疗组（吡拉西坦0.5 g/kg）,APS高、中、低剂量组（APS 0.8、0.4、0.2 g/kg）。采用Aβ1-42双侧脑室注射大鼠诱导建立AD模型。给予APS连续灌胃治疗30 d后取材,观察大鼠海马镜下超微结构、计算脾和胸腺脏器指数。采用酶联免疫吸附法检测海马Aβ_（1-40）和LRP1,血清Aβ_（1-40）水平。采用RT-PCR法检测海马LRP1 mRNA的含量。结果与模型组比较,APS高、中剂量组脑海马形态明显改善,脾和胸腺脏器指数明显增加（P〈0.05）,海马组织Aβ_（1-40）水平明显降低（P〈0.05）,海马组织LRP1和血清Aβ_（1-40）水平明显增加（P〈0.05）。结论 APS能改善AD大鼠海马形态结构,增加海马LRP1水平、脾和胸腺脏器指数。

英文摘要：

Objective Effects of astragalus polysaccharides（ APS） on ultrastructure and lipoprotein receptor-related protein 1（ LRP1） of hippocampus in Alzheimer＇s disease（ AD） rat. Methods Wistar rat were randomly divided into control group,model group,treatment group（ Piracetam 0. 5g / kg）,APS high-dose group（ APS 0. 8 g / kg）,APS medium-dose group（ APS 0. 4 g / kg）,APS low-dose group（ APS 0. 2 g / kg）. Aβ1-42 was injected into the bilateral hippocampus of rat to induce AD models. The rat were killed after 30 days continuous treating. After the treatment all animals were sacrificed,ultrastructure of hippocampus was observed,calculated the organ coefficients of splenic and thymus. The levels of Aβ_（1-40） and LRP1 in the hippocampus were measured by enzyme-linked immunosorbent assay（ ELISA）. The levels of Aβ_（1-40） in the serum were measured by ELISA. The content of LRP1 mRNA in the hippocampus was determined by reverse-transcription PCR（ RT-PCR）. Results Compared with the model group,the APS highdose group and APS medial-dose group brain maintain normal morphological structure of hippocampus was significantly increased,the organ coefficients of splenic and thymus significantly increased（ P 0. 05）,the levels of Aβ_（1-40） in the hippocampus were significantly decreased（ P 0. 05）,the levels of LRP1 in the hippocampus and the levels of Aβ_（1-40） in the serum were significantly increased（ P 0. 05）. Conclusion APS can maintain normal morphological structure of hippocampus of AD rat,increased LRP1 responses in the hippocampus tissue,organ coefficients of splenic and thymus.