Cellular and molecular mechanisms of asbestosis.

O and experimental exposure to asbestos is associated with the development of peribronchiolar and interstitial pulmonary fibrosis.1 L ike other asbestosassociated diseases of the respiratory tract (ie, mesothel ioma and bronchogenic carcinoma), asbestosis appears to involve alterations in differentiation and proliferation o f affected cel l types. W h e t h e r the disease process involves e i ther an increase in replication o f fibroblasts in the lung or an enhanced ability o f individual fibroblasts to produce more collagen or both is uncertain. To address this question, we used a combination o f in vitro and in vivo approaches.