Fig. 1

Intratracheal bleomycin-induced pulmonary fibrosis. Representative optical microscopy images of mouse lungs. Hematoxylin-eosin stain for saline (a) and bleomycin-treated lungs at day 7 (b), day 14 (c), day 21 (d) and day 28 (e). Scale bars indicate 500 μm (100 μm in inset). Masson’s trichrome stained saline (f) and bleomycin-treated lungs at day 7 (g), day 14 (h), day 21 (i) and day 28 (j). Scale bars indicate 200 μm. k Total and differential cell counts in bronchoalveolar lavage (BAL) fluid from saline and bleomycin-treated mice. BAL fluid was collected at days 7, 14, 21 and 28 after intratracheal bleomycin administration. Total cell numbers and lymphocyte counts in BAL fluid from bleomycin-treated lungs were significantly higher than in controls. Neutrophils in BAL fluid from bleomycin-treated lungs tended to be increased on day 7. l Total protein concentration in BAL fluid from saline and bleomycin-treated mice. BAL fluid was collected at days 7, 14, 21 and 28 after intratracheal bleomycin administration. Total protein concentrations in BAL fluid from bleomycin-treated lungs were significantly higher compared with that in controls. m Hydroxyproline content in lungs from saline and bleomycin-treated mice. Lung homogenates from saline and bleomycin-treated mice (n = 3 per group) were analyzed for hydroxyproline with a colorimetric assay. Hydroxyproline content was higher in the bleomycin-treated lungs. Results are means ± standard error, from three to seven mice. *p < 0.05, compared with saline-treated mice; **p < 0.05, compared with bleomycin-treated mice on day 7