Fig. 1

Hyperoxia induces acute lung injury. Mice were exposed to over 90% oxygen for 12, 24, 48, 72 h respectively as indicated. Sham mice were included as controls. a Representative H&E- and Masson trichrome-stained lung sections. Morphology was examined using light microscopy. Scar bar = 20 μM. b Histopathological scoring of lung injury was analyzed in each group. c Lung wet/dry weight ratio was analyzed at varying times exposure to over 90% oxygen. d TEM images of AECII both in sham and hyperoxia (24 h) groups. The white arrow indicates lamellar body. The black arrows indicate mitochondria. Images are representative of three independent experiments. Data are shown as mean ± SEM. n = 3 per group. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001. ^*Compared with the sham group