Figure 1

Representative photomicrographs of lung tissue (H & E staining). (A) (10 × scale bar 100 μm) and (B) (20 ×, scale bar 50 μm)—Control group: thin alveolar septa and no significant inflammation. (C) (10 ×, scale bar ×100 μm) and (D) (20 ×, scale bar 50 μm)—PM group: perivascular and peribronchial inflammatory infiltration and mild inflammation in the alveolar septa. (E) (10 ×, scale bar 100 μm) and (F) (20 ×, scale bar 50 μm)—LPS5w group: perivascular and peribronchial inflammatory infiltration and mild inflammation in the alveolar septa, predominantly composed of mononuclear cells. (G) (10 ×, scale bar 100 μm) and (H) (20 ×, scale bar 50 μm)—LPS + PM group: inflammatory infiltration along the bronchovascular bundle and with moderate presence of inflammatory cells in the alveolar septa, predominantly mononuclear cells. In addition, the lung tissue of the LPS + PM group showed enlarged alveoli with irregular distribution. Blue arrows = infiltration of inflammatory cells in the peribronchial and perivascular areas. Red arrows = interalveolar inflammatory cells.