目的 探讨17α雌二醇（ESUB>2/SUB>α）对稳定表达人β-淀粉样前体蛋白（APP）/早老因子-1（PS1）即APP /PS1基因的神经母细胞瘤细胞株（Neuro-2a）（APP/PS1 NSUB>2/SUB>a）β-淀粉样蛋白（Aβ）产生的影响及可能机制。方法 将APP/PS1 NSUB>2/SUB>a细胞用10×10SUP>-9/SUP> mol/L E2α预处理2d，更换培养液后，分别进行如下处理：1.加入不同浓度ESUB>2/SUB> a（25nmol/L、50nmol/L、100nmol/L、200nmol/L）和溶媒（对照组），用免疫印迹法(Western blotting)检测APP/PS1 NSUB>2/SUB> a细胞内和细胞外的Aβ蛋白水平及细胞BACE1蛋白水平；2.加入 100nmol/L ESUB>2/SUB>α、20nmol/L葡萄糖和5mIU葡萄糖氧化酶（GOX）。24h后，进行二氢乙啶(DHE)染色观察APP/PS1 N2a细胞中活性氧（ROS）含量的变化。结果 不同浓度E2α（25nmol/L、50nmol/L、100nmol/L、200nmol/L）处理后，细胞外Aβ蛋白水

Objective To investigate the effects of 17α-estradiol (ESUB>2/SUB>α) on the release of β-amyloid protein (Aβ) with the transgenic cells β-amyloid precursor protein（APP）/ presenilin-1（PS1）Neuro-2a (NSUB>2/SUB>a), and explore the potential mechanism of such effect. Methods APP/PS1 NSUB>2/SUB>a cells were pretreated with 10×10SUP>-9/SUP> mol/L Eα for 2 days, then changed the culture medium, and treated with different methods: 1. Cells were treated with either E2α（25 nmol/L, 50 nmol/L, 100 nmol/L, 200 nmol/L）or vehicle, the protein level of Aβ and β-secretase-1（BACE1) both intracellular and extracellular of APP/PS1 N2a cells were detected by Western blotting. 2. Cells were treated with 100 nmol/L E2α, 20 nmol/L glucose and 5 IU glucose oxidase(GOX), followed by exposure to the glucose oxidase (G/Gox) to induce oxidative stress. After 24 hours, the change of the Reactive oxygen species（ROS）contents in APP/PS1 NSUB>2/SUB>a cells was observed for dihydroethidium(DHE). Results The extracellular level of Aβin APP/PS 1 NSUB>2/SUB>a cells treated with various concentration (25 nmol/L,50 nmol/L,100 nmol/L,200 nmol/L/L)ESUB>2/SUB>α were significantly decreased(EM>P/EM> <0.05). There was no change in the intracellular levels of Aβ and the levels of BACE1(EM>P/EM> >0.05). ESUB>2/SUB>α reduced the ROS produced by APP/PS1 NSUB>2/SUB>a cells after G/Gox treatment. Conclusion ESUB>2/SUB>α may reduce the production of extracellular Aβ and its mechanism may be related