Infiltration of inflammatory cells after instillation of ATP. A. Hematoxilin-eosin staining of the lung. The instillation of ATP increased the thickness of the alveolar walls, and caused alveolar hemorrhages and infiltration of neutrophils and macrophages in 24 h. These histological changes were not enough mitigated by the simultaneous administration of PPADS. Bars = 100 μm in the upper panels, and = 50 μm in the lower panels. B. Total and differential cells count in BAL fluid after instillation of ATP. The instillation of 100 mM ATP caused significant increase in total cells, macrophages and neutrophils in BAL fluid in 24 h. n = 8 mice in each group; *p < 0.05 vs. control.