Neutrophil recruitment and airspace enlargement in lung tissue. a) The right lower lobes of mice were dissected and stained with hematoxylin and eosin (×200 magnification). ST disturbed the neutrophil accumulation in the peribronchial airway. b) Mean alveolar airspace (MAA), a morphometrical analysis, was assessed using Image Pro-Plus 5.1 software as described in the Methods section. n = 5 in all groups. Data are shown as the mean ± S.E.M. Statistical analyses were conducted by one-way ANOVA followed by Newman-Keuls Multiple Comparison test; ###p < 0.001 vs. AIR, ***p < 0.001 vs. CS.