Figure 5

Pathological changes in the lungs from BO groups and NC groups. (A,B) HE staining shows obvious obstruction in small airways, with significant infiltration of inflammatory cells in the surrounding and luminal areas of affected small airways. (C,D) Mason’s trichrome staining shows more obvious fibrotic changes in the bronchi, with blue staining around the trachea indicating increased deposition of collagen protein and obvious narrowing and deformation of the tube wall. Tissues for A and C were obtained from 2, 3-butanedione-induced BO mice and their control group. Tissues for (B) and (D) were obtained from nitric acid-induced BO mice and their control group. In the HE-stained images, the scale bar represents a unit of 200 μm, while in the Masson-stained images, the scale bar represents a unit of 100 μm.