Prevention of LPS-induced lung injury in Cav1−/− mice and its reversal in DKO mice. A: Representative micrographs of H&E staining of lung sections from mice challenged with LPS (7.5 mg/kg BW). At 20 hours post-LPS challenge, lungs were fixed and processed for histological analysis. Cav1−/− lungs showed significantly less leukocyte infiltration at 20 hours post-LPS challenge compared with other lungs. Scale bar = 200 μm. B: Quantification of leukocyte infiltration in lungs. Lungs from mice challenged with either PBS (Basal) or LPS (7.5 mg/kg BW) for 20 hours were fixed and processed for H&E staining. Leukocytes were counted using a stereomicroscopy. Data are expressed as mean ± SD (n = 4 to 5). *P < 0.05 versus wild-type (WT), DKO, or NOS3−/−. C: MPO activities in lungs challenged with either PBS (Basal) or LPS (7.5 mg/kg BW, 20 hours). Data are expressed as mean ± SD (n = 4 to 5). *P < 0.05 versus wild-type, DKO, or NOS3−/−.