Effect of rapamycin on pulmonary fibrosis in rats / 中国医师杂志

ABSTRACT

Objective To explore the effect of rapamycin on pulmonary fibrosis in rats and its mechanism.Methods Pulmonary fibrosis model was induced by intratracheal instillation of bleomycin (5mg/kg).Control group was treated by intratracheal instillation of saline (1.25 ml/kg) to obtain the negative control.The rats of the rapamycin-treated group were given rapamycin (1 mg/kg per day) by gastric perfusion for consecutive 10 days beginning on the third day after intratracheal instillation of bleomycin.On the 28th day,all rats were sacrificed and the peripheral blood and the lung tissues were harvested.Lung tissues were performed hematoxylin-eosin (HE) staining.The severity of pulmonary fibrosis in rats was assessed by Ashcroft score.Lung tissues were performed immunohistochemical staining to detect the expression of transforming growth factor beta (TGF-beta).The expression level was judged by integrated optical density.Results The severity of pulmonary fibrosis was improved in rats of rapamycin-treated group compared with the rats of bleomycin-treated group.A significant difference in Ashcroft score was found between rapamycin-treated group and bleomycin-treated group(2.92 ± 0.64 vs 5.76 ± 1.76,P ＜ 0.01).The expression level of TGF-β was increased in rapamycin-treated group compared with the normal control group (5520.00 ± 1614.20 vs 3370.00 ± 1478.14,P ＜0.01).The expression level of TGF-β was decreased in rapamycin-treated group compared with the bleomycin-treated group (5520.00 ± 1614.20 vs 7772.00 ±1526.46 P ＜0.01).Conclusions Rapamycin can prevent bleomycin-induced pulmonary fibrosis.