Figure 7

Assessment of airway mucus and respiratory fibrosis following hyperoxia. A. Representative images of periodic acid-Schiff’s reagent staining of normoxic and hyperoxic lung airways, counterstained with Mayer’s hematoxylin (blue). Mucin-secreting cells are stained purple and are marked with arrows. No mucus deposits are present in the airways (aw) of either normoxic or hyperoxic mice. Scale bar = 100 μm. B. Representative images of Masson’s trichrome staining of normoxic and hyperoxic lungs. A collagen layer (stained blue) around the airways (aw) and blood vessels (bv) is present in both normoxic and hyperoxic lungs and is marked with black arrows. Nuclei are stained purple, cytoplasm is stained red. No abnormal collagen deposits (i.e. thickening of lung tissue area) are observed in hyperoxic lungs at any stage. Scale bar = 100 μm.