Production of Superoxide and Nitric Oxide by Alveolar Macrophages in the Bleomycin-Induced Interstitial Pneumonia Mice Model

To elucidate the potential role of superoxide (O2-) and nitric oxide (NO) in the pathogenesis of interstitial pneumonia, the quantity of O2- and NO produced by the alveolar macrophages (AM) were determined in the bleomycin (BLM)-induced interstitial pneumonia mouse model. The production of O2- and NO increased on days 7, 14 and 21 after BLM injection. Strong expression of peroxynitrite (ONOO-) was seen in AM by using immunostaining for nitrotyrosine. The hydroxyproline contents increased on day 21 after BLM injection. O2- and NO are thought to play an important role in the pathology of fibrosis.