[The role of pulmonary epithelial cells in lung cellular reaction to asbestos exposure].

The damage of pulmonary alveolar epithelial cells occurs in many inflammatory conditions caused by various agents, e.g. asbestos, that involve interstitial lung disease in experimental animals and in humans. After exposure to asbestos alveolar epithelial cells contain significant amount of asbestos fibers and show histologic changes which indicate a marked epithelial injury. The alveolar epithelial injury is manifested by swelling, debris and patchy necrosis of type I cells partly detached from its basement membrane. Besides, regenerative hyperplasia of type II pneumocytes with ultrastructurally cisternal dilation of the rough endoplastic reticulum and significantly greater number of lamellar bodies are found. Following the cessation of exposure, epithelial cells are cleared out of asbestos fibers and return to the normal condition. These data provide insight into pathogenesis of diffuse lung disease and the role of alveolar cells in early and late phases of asbestosis.