Study of leukotrienes inhibitor on bleomycin-induced pulmonary fibrosis in rats

Abstract

Objective To investigate the effect of zileuton, leukotrienes inhibitor, on pulmonary fibrosis induced by bleomycin(BLM) in the rats. Methods Fifty-four adult male Sprague-Dawley rats were divided randomly into three groups: BLM group (M group), control group (C group) and leukotriene inhibitor group(S group). Each group contained eighteen mice. S group was treated with zileuton everyday at a dose of 100 mg/kg after a single intratracheal instillation of BLM at a dose of 5 mg/kg; M group was treated with saline instead of zileuton after instillation of bleomyein;C group was treated with saline instead of zileuton and BLM. Six rats in each group were killed on 7,14 and 28 days after instillation. The rat lungs were harvested for HE and Masson trichrome stain, hydroxyproline content was determined, immunohistochemistry was used to detect the expressions of α-SMA and TGF-β1 in the lung tissues. Results The hydroxyproline content of M group was significantly higher than that of S group, the degree of alveolitis in S group was ameliorated as compared with that in M group(P＜0.05);a significantly reduced fibrosis was observed in S group compared with that in M group. The expression of TGF-β1 and α-SMA in lung tissue of S group was significantly lower than that of M group. Conclusions Leukotriene inhibitor could reduce the degree of bleomycin-induced pulmonary fibrosis in rats. It may inhibite the proliferation of fibroblasts by inhibiting the expresson of TGF-β1 in lung tissue. Key words: Leukotrienes inhibitor; Pulmonary fibrosis; Bleomycin