ABSTRACT
Aim To investigate the effect of magnesi-um isoglycyrrhizinate (MgIG)on radiation -induced pulmonary fibrosis in mice and the mechanism.Meth-ods Fifty female C57BL/6 mice were randomly divid-ed into control group,irradiation (RT)group,MgIG group,RT +MgIG group and RT +dexamethasone (DXM)group,with 1 0 mice in each group.Except for control group and MgIG group,the remaining mice were given a single 1 5Gy 60 Co γray on whole lung. The mice in each group were administered 2 h before irradiation and each day after irradiation:MgIG group and RT +MgIG group were administered with MgIG (1 00 mg·kg -1 )by intraperitoneal injection;control group and RT group were administered with normal sa-line (20 mL·kg -1 )by intraperitoneal injection;RT+DXMgroup was administered with DXM(0.5 mg· kg -1 )by intraperitoneal injection.After 1 2 weeks,the mice were sacrificed and lung tissues were taken out. The degree of alveolitis and pulmonary fibrosis were observed by HE staining and Masson staining.The ex-pressions of type Ⅰ collagen,type Ⅲ collagen and TGF-β1 protein were detected by immunohistochem-isty.Results The alveolitis,pulmonary fibrosis and expressions of type Ⅰ collagen,type Ⅲ collagen, TGF-β1 ,p-Smad2,p-Smad3 increased significantly in RT group compared with control group (P <0.05 ), and were significantly lower in RT +MgIG group and RT +DXMgroup than those in RT group(P <0.05). Conclusion MgIG can improve radiation-induced pulmonary fibrosis in mouse lung tissue,and its mech-anism may be related to the influence of MgIG on TGF-βsignaling pathway.
ABSTRACT
Objective To explore the protectional function of CpG ODN 1826 against radiation pulmonary fibrosis in rats.Methods The rat left lung was exposed to 20 Gy of 6 MV X-rays for establishing a radiation pulmonary fibrosis model.SD rats were randomly divided into control group,irradiated group and intervention group,with 30 rats in each group.CpG ODN 1826 was intraperitoneally injected into rats at 0,1,2,5 and 7 d post-irradiation.The rats were terminated at 5,15,30 and 90 d post-irradiation,and the lung indexes were recorded.Paraffin sections of the radiated lung were conducted with HE staining and Masson staining,the pulmonary fibrosis scores were recorded.The serum concentrations of TGF-β1 and hydroxyproline (Hyp) were measured.Results The radiation pulmonary fibrosis rat model was successfully established.The lung indexes of the control group were lower than those of the irradiated and intervention groups at 5 d post-irradiation (t =3.046,2.252,P ＜ 0.05).The lung indexes of the intervention group were lower than those of the irradiated group (t =4.120,5.226,5.719,P ＜ 0.05).Pulmonary fibrosis scores of intervention group were lower than those of irradiated group (t =3.212,4.959,P ＜ 0.05).The serum concentrations of TGF-β1 of irradiated group were higher than those of the intervention group (t =4.138,5.924,4.138,5.924,P ＜ 0.05).The Hyp in the lung of irradiated group was higher than that of intervention group (t =7.527,8.416,P ＜ 0.05).Conclusions CpG ODN1826 will not worse the radiation pulmonary fibrosis,on the contrary,it could reduce the serum concentrations of TGF-β1 and the lung content of Hyp in radiation pulmonary fibrosis,and protects rat against radiation pulmonary fibrosis.