Effect of interferon-γ on bleomycin-induced pulmonary fibrosis in rats

Objective To observe the effects of interferon-γ (IFN-γ) on lung injury induced by bleomycin and its mechanism. Methods Sixty-six SD rats were randomly divided into three group: the normal control group (group N, n=24), the bleomycin group (group B, n=24) and IFN-γ treatment group (group I, n=18). The degree of lung injury and the concentrations of tumor necrosis factor-α (TNF-α) and IFN-γ in bronchoalveolar lavage fluid (BALF) and serum were measured. Results The degree of lung injury in group I was severer than group B, but with no significant difference. The concentration of TNF-α in BALF on 17, 21, 28 days and in serum on 21 and 28 days were significantly increased after IFNγ administration compared with group N and group B (all P0.05). The concentration of IFN-γ in BALF and serum increased on 21 and 28 days in group I (all P0.05). Conclusion IFN-γ might aggravate lung injury induced by bleomycin, and it might attribute to an increase in TNF-α.