Effect of gefitinib on bleomycin-induced pulmonary fibrosis and pulmonary expression of HSP70.

Wild-type mice (A, B, E, G, H) and transgenic mice expressing HSP70 (C, D, F, G, J) were orally administered gefitinib (200 mg/kg) or vehicle once per day for 3 days (from day 0 to day 2), then treated once only with or without 1 mg/kg (for wild-type mice) or 2 mg/kg (for the transgenic mice) bleomycin (BLM) (day 3). Mice were then orally administered gefitinib (200 mg/kg) or vehicle once per 2 days for 14 days (from day 3 to day 17). Sections of pulmonary tissue were prepared at day 17 and subjected to histological examination (H & E staining (A, C) or Masson's trichrome staining (B, D)) (scale bar, 50 µm) (A-D). Pulmonary hydroxyproline levels at day 17 were determined (E, F). Total protein was extracted from pulmonary tissues at day 17 and analyzed by immunoblotting with an antibody against HSP70 or actin (G, H, J). The intensities of the HSP70 bands were determined (one of the gels is shown in H) and are expressed relative to the control (I). Values are mean ± S.E.M. *P<0.05; **P<0.01; n.s., not significant.