ABSTRACT
Objective To investigate the therapeutic effects and mechanism of anti-radiation pneumonia decoction(ARPD) on radiation induced lung fibrosis in rats.Methods One hundred and five male SD rats in a SPF grade were divided into Chinese medicine group,single radiation group and control group by random digits table method,with 35 in each group.After anesthetization,rats in Chinese medicine and single radiation groups were exposed to 6 MV X-rays at the dose of 15Gy.Rats in Chinese medicine group were treated with ARPD at the dosage of 10 ml·kg-1 ·d-1 once a day,but rats in single radiation group did not receive ARPD treatment.Rats in control group were treated with neither irradiation nor drugs.Five rats of each group were killed and the lung tissues and blood samples were collected at 15,30,60,75,90,105 and 140 d.The pathological changes of lung tissues were observed and the tissue protein and gene expressions of TGF-β1,PAI-1 and collagen type Ⅲ(C Ⅲ) were assayed by Western blot and RT-PCR.ELISA was used to detect serum TGF-β1 and plasma PAI-1.Tissue and serum HYP were determined by acid hydrolysis and alkaline hydrolysis methods respectively.Results Inflammation was found in the lung tissues of all the exposed rats.Obvious pathological lung fibrosis was found at 60 d,the inflammation and the fibrosis in treated group were slighter than those in single radiation group.In Chinese medicine group,the protein and gene expression levels of TGF-β1,PAI-1,C Ⅲ 30 d(Protein:t =2.49-3.74,t =2.63-4.57 and t =2.76-3.83;Gene:t =2.59-4.33,t =2.83-4.62 and t =2.83-3.96,P＜0.05),serum TGF-β1 and plasma PAI-1 15 dlater (t =2.85-6.27 and t =3.69-5.27,P＜0.05),and the levels of tissue and serum HYP60 dlater (t=3.65-4.40 and t =6.56-3.75,P＜0.05),all of them were lower than those in single radiation groups.There were significant positive correlations between tissue TGF-β1 and PAI-1 as well as C Ⅲ (Protein expression:r =0.604,0.759,P ＜0.05;Gene expression:r=0.519,0.816,P＜0.05).Conclusions ARPD may inhibit the pulmonary fibrosis by decreasing the levels of TGF-β1,PAI-1 and C Ⅲ.