Figure 3

Histopathology. Lung sections from control rats showed normal histology (Figure 3A, inset) while lungs from rats exposed to barn and challenged with saline (Figure 3B and inset) and unexposed rats challenged with E. coli LPS (Figure 3C and inset) showed infiltration of neutrophils (arrows) and macrophages (arrowheads) into the lung septum. Lung sections from rats exposed to barn and challenged with E. coli LPS showed septal infiltration of neutrophils (D-F and insets; arrows), macrophages (D, arrow heads) and thickened septa (D, curved arrow), margination and attachment of leukocytes to the blood vessel wall along with perivascular infiltration (Figure 3E, thin arrows and inset) and damage to the bronchiolar epithelium (F, double arrows and inset). Original magnification (A-F): 400× and bar = 50 μm (A-F).