气态甲醛对大鼠肺组织影响的病理学观察

Pathological Effects of Formaldehyde Inhalation on Lung of Rats

为了研究大鼠吸入甲醛后其肺组织病理结构的改变并探讨其损伤机理,以雌性Wisar大鼠为实验材料,采用动式吸入方式染毒15d(暴露组甲醛浓度32～37mg·m-3,每日暴露4h)后,取肺组织进行光镜及透射电镜观察.光镜观察结果表明,甲醛暴露后,大鼠肺组织主要表现为间质性肺炎和肺泡性肺炎的病理学特点,肺泡壁毛细血管扩张、充血、出血严重,个别区域可见大量炎细胞浸润,肺内细支气管和肺泡腔内见大量血细胞,部分肺泡腔内有透明膜形成,内含脱落的肺泡上皮细胞.电镜观察结果表明,甲醛暴露后,大鼠肺泡上皮细胞损伤严重,线粒体嵴断裂、肿胀、空泡化,部分肺泡上皮细胞胞膜溶解,细胞器丢失,细胞坏死、脱落.推测甲醛吸入可致大鼠肺病理损伤,损伤机理可能与自由基损害和醛糖还原酶(AR)表达变化有关.

In order to study pathological changes of lung in rats that have inhaled formaldehyde and investigate rat lung lesion mechanism, female Wistar rats were exposed to FA for 15 days （FA concentration was 32～37mg·m^-3, 4h·d^-1）in dynamic inhalation mode, after that, lung tissue was obtained and observed by light microscope and transmission electron microscope. Light microscope showed that the main pathological features of lung tissue were interstitial inflammation and alveolar inflammation with angiotelectasis, congestion and bleeding in alveolar wall, a lot of inflammatory cells infiltrate, a great quantity blood cells in bronchioles and alveolar spaces, hyaline-membrane formation and containing caducous alveolar epithelial cells in some alveolar spaces. Transmission electron microscope showed that there were obvious injuries in alveolar epithelial cells with mitochondria cristae break, swelling and even vacuolization. Cytomembrane dissolving, organelle loss, cell necrosis and ablate were observed in some alveolar epithelial cells. It can be concluded that FA can induce pathological damage to rat lung, and its mechanism can be related to free radical lesion and Aldose Reductase（AR）expression change.