Pathology stained by Masson's trichrome stain was shown in different groups. A. The alveolar structure with some exudation in the right lower lung was shown in the Sham group. B. Some collapsed alveolar structures, atelectasis with thickened alveolar septa (white arrow), collagen fibers, and a few exudative cells in the alveolar space were shown in the Ischemia group. C. Incomplete and destructed alveolar structure with a large number of exudative cells and exudation (white arrow) were seen within the alveolar spaces in the Reperfusion group. D. Alveolar structures with exudative cells and exudation were shown in the Inhaled NO group, but less when compared with the Reperfusion group (white arrow).