Studying the influence of Candesartan cilexetil on the lung fibrosis in rats exposed to silica

Objective To explore the effects of Candesartan cilexetil on the rats exposed to silica.Method Ninety-six wistar rats were randomly divided into model-group,intervention-group and control-group (32 rats a group).The intervention-group,model-group and control group were orally exposed to Candesartan cilexeti ( 10 mg/kg) and normal solution for a week,respectively.Then the model and intervention groups were exposed to silica by intratracheal infusion of silica dust suspension (50 mg/ml),the control group was exposed to 0.5 ml normal solution for 2 days.On the 3rd,7th,14th and 28th days after exposure to silica,8 rats of each group were sacrificed,respectively.The samples of lung tissues were collected.The lung/body coefficients were detected.The pathological examinations were performed by HE and Masson staining.The levels of ACE in the lung tissues were observed by immunochemistry staining.The levels of TGF-β1 and Ang Ⅱ in the BALF were examined by ELISA.Results On the 3rd,7th,14th and 28th days after exposure,the levels of alveolitis and pulmonary fibrosis in the intervention group were significantly alleviated as compared with model group,and the lung/body coefficients in the intervention group,which were significantly lower than those in model group respectively (P＜0.01).As compared with control group,the levels of TGF-β1 and Ang Ⅱ of the BALF in the model and intervention groups significantly enhanced (P＜0.01).As compared with model group,the levels of TGF-β1 and Ang Ⅱ of the BALF in the intervention group significantly decreased (P＜0.01).As compared with control group,the levels of ACE of the lung tissues in the model and interventiou groups significantly increased (P＜0.01 ).But the level of ACE of the lung tissues in the intervention group was significantly lower than that in the model group (P＜0.01).Conclusion The early Candesartan cilexetil intervention could significantly decrease the levels of alveolitis and lung fibrosis,declined the levels of TGF-β1 and Ang Ⅱ of BALF and downregulated the expression level of ACE in lung tissues in rats exposed to silica. Key words: Silicosis;  Candesartan cilexetil;  Transforming growth factor beta;  Angiotensins