中文摘要：

目的观察颅脑创伤（TBI）大鼠脑海马组织β-淀粉样蛋白前体蛋白（APP）的表达以及亚低温干预对APP表达的影响。方法30只Wistar大鼠按随机数字表法分为对照组、TBI常温组[（37．0±0．5）℃]和TBI亚低温组[（32．0±O．5）℃]，每组10只。用液压冲击致伤法建立中度TBI动物模型，常温或亚低温干预6h后，观察大鼠神经功能行为学变化，苏木素-伊红（HE）染色观察海马组织病理学改变，逆转录-聚合酶链反应（RT-PCR）检测海马区APPmRNA表达，组织免疫荧光和蛋白质免疫印迹法（Western blotting）检测APP、β-淀粉样蛋白（Aβ）蛋白表达。结果与对照组比较，TBI常温组神经功能行为评分（分）明显降低（26．08±1．23比35．00±0．00），脑海马组织存活的神经元数量减少，APP阳性神经元数量明显增加，APPmRNA及相关蛋白表达均明显升高（APPmRNA：1．491±0．122比0．711±0．082，APP蛋白：1．782±0．034比0．763±0．023，Aβ蛋白：1．321±0．240比0．092±0．002，均P〈0．05）。与TBI常温组比较，TBI亚低温干预能显著提高大鼠TBI后神经功能行为评分（32．29±1．31比26．08±1．23），增加脑海马区存活的神经元数量，减少APP阳性神经元细胞数，APPmRNA及其相关蛋白表达均显著降低（APPmRNA：0．733±0．084比1．491±0．122，APP蛋白：0．653±0．026比1．782±0．034，Aβ蛋白：0．123±0．003比1．321±0．240，均P〈0．05）。结论大鼠TBI后的APP蓄积可能是发生继发性脑损伤（SBI）的机制之一，亚低温可通过减少APP的生成来减轻SBI的程度，起到神经保护作用。

英文摘要：

Objective To observe the effects of mild hypothermia on expression of β-amyloid protein precursor （APP） in bippocampus of rats following traumatic brain injury （TBI）. Methods Thirty Wistar rats were randomly divided into three groups ： control group without TBI but with normothennia, TBI with normothermia [ （37.0±0.5 ）℃ 3 group and TBI with mild hypothermia[ （32.0 ＋ 0.5 ） ℃ 3 group （each n= 10）, the thermal treatment being for 6 hours in the three groups respectively. The TBI rat model was established by a fluid percussion device. The behavior scales of nerve function were estimated, then rats were sacrificed and the brain hippocampus tissues were prepared for hematoxylin and eosin （HE） staining to observe the changes of histopathology. The level of APP mRNA in the hippocampus was examined by reverse transeription-polymerase chain reaction （RT-PCR）, and protein expressions of APP and β-amyloid protein （A β ） were analyzed by immunofluoreseence and Western blotting, respectively. Results Compared with controls, the neural function behavior score was reduced significantly （ 26.08 ±1.23 vs. 35.00 ±0.00, P 〈 0.05 ）, the number of survival neurons of hippocampus was decreased, the number of positive neurons of APP was increased, and APP mRNA and related protein of APP also increased obviously in the TBI normothermia group （APP mRNA ： 1.491±0.122 vs. 0.711±0.082, and APP protein ： 1.782±0.034 vs. 0.763±0.023, Aβ protein ： 1.321 ± 0.240 vs. 0.092±0.002, all P〈0.05）. Compared with the TBI normothermia group, the neural function behavior score was improved significantly （32.29 ± 1.31 vs. 26.08 ±1.23 ）, the number of survival neurons of hippocampus was increased, and the number of positive neurons of APP, the expressions of APP mRNA and Aβ were decreased significandy in the TBI group treated with mild hypothermia （APP mRNA： 0.733 ±0.084 vs. 1.491±0.122, APP protein ：0.653±0.026 vs. 1.782±0.034, Aβ protein ：0.123±0.003 vs. 1.321±0.2