Figure 1.

Tracheal instillation of bleomycin causes lung injury and increases lung weight. (A) Gross morphology and histology of right lung of a saline-treated mouse (left) and bleomycin-treated animal (right). Bleomycin instillation causes multifocal lesions on the lung, which are associated with infiltration of inflammatory cells, disruption of alveoli, thickening of the alveoli walls, and increased deposition of collagen. Note that gross lung images are not to scale. Hematoxylin, eosin, and picrosirius red staining; magnification, 400×. (B) Bleomycin instillation leads to doubling of lung wet weight, even when (C) expressed relative to body weight (BW). §, P < 0.0001.