Pathological Effects of Formaldehyde Inhalation on Lung of Rats
气态甲醛对大鼠肺组织影响的病理学观察

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.