中文摘要：

目的探讨Ⅱ型肺泡上皮细胞（AECⅡ）凋亡在被动吸烟肺气肿大鼠肺功能下降中的相关作用。方法选取907,清洁级雄性sD大鼠，完全随机平均分成6组，A组正常对照组，B、C、D、E、F组大鼠被动吸入不同浓度香烟烟雾。采用小动物肺功能仪测定各组大鼠肺功能、肺组织病理学检测、Real-timePCR测定肺泡表面活性蛋白A（SPA）和SPCmRNA水平、免疫组织化学法检测SPA和SPC蛋白表达水平，TUNEL与SPC双重免疫荧光染色分析AECⅡ凋亡情况。结果 当香烟烟雾中一氧化碳（CO）浓度达到（300±10）ppm以上时，大鼠肺功能中气道阻力（AR）明显增加、肺动态顺应性（Cdyn）及呼气峰值流速（PEF）降低（P〈0．05）；大鼠肺组织出现明显肺气肿样表现，肺泡平均内衬间隔（MLI）和平均肺泡面积（MAA）显著增加（P〈0．05）；肺组织中SPA和SPCmRNA及蛋白表达水平明显下降（P〈0．05），AECⅡ凋亡百分比显著增高（P〈0．05）。结论AECII凋亡在被动吸烟建立的大鼠肺气肿发生发展过程中起重要作用。

英文摘要：

Objective To study the effects of type II alveolar epithelial cells apoptosis on pulmonary function decline in rats with emphysema. Methods Ninety SPF-grade male Sprague-Dawley rats were randomly sorted into six groups. A group was control group; rats form B, C, D, E and F groups were exposed to different passive smoking concentrations. Small animal lung function instrument was used to analyze the pulmonary function of each rat. Histological changes of rats were analyzed by H＆E staining, and surfactant protein A （ SPA ） and SPC mRNA expressions were detected by Real-time PCR; SPA and SPC protein expressions were measured by immunohistochemical analysis. TUNEL/SPC immunofluorescence staining was used to analyze the apoptosis of type II alveolar epithelial cells （ AEC Ⅱ ） . Results When the concentration of carbon monoxide （ CO ） in cigarette smoke was above 300 ＋ 10 ppm, the airway resistance （ AR ） from rats was increased significantly, and the pulmonary dynamic compliance and peak expiratory flow were obviously decreased in lung function （ P〈0.05 ） . Enlargement of airspace was observed and the amount of alveoli was decreased in the lung tissues, and the mean linear intercept and mean alveolar airspace from rats were significantly increased （ P〈0.05 ） ; SPA and SPC mRNA and protein expressions were markedly decreased （ P〈0.05 ） ; and the percentage of AEC Ⅱ apoptosis was significantly increased （ P〈0.05 ） . Conclusions AEC Ⅱ apoptosis plays an important role in the development of emphysema in rats induced by passive smoking.