Effect of recombinant human tumor necrosis factor-O receptor on tumor necrosis factor in rats with radiation-induced lung injury

Objective To observe the effect of recombinant human tumor necrosis factor-O receptor(rhTNFR:Fc)on tumor necrosis factor(TNF-α)and interleukin-6(IL-6)in radiation-induced lung injury,thus to find out a novel therapeutic strategy.Methods Seventy-two female SD rats were divided into 3 groups:control group,irradiation group and treatment group administered with rhTNFR:Fc.Rats in the irradiation group and treatment group were irradiated with linear accelerator at a single dose of 25 Gy.After irradiation rats in the treatment group were intraperitoneal injected with rhTNFR:Fc at a dose of 5 mg·kg-1 twice in the first week while rats in the control group and irradiation group were injected with the same volume of saline.Rats were killed in the 1,4,8 and 24 weeks.Samples of lung tissues were observed by using HE staining.Expression of TNF-α in lung was determined by immunohistochemistry while TNF-α in serum was determined by ELISA.Data were analyzed by SPSS software.Results Expressions of TNF-α in lung and serum increased significantly after irradiated in the irradiation group compared with the control group and reached the peak in the 4 weeks(P0.01,q=5.63,q=6.21);Though expressions of TNF-α in the treatment group also increased compared with the control group,the difference between the irradiation group and treatment group was statistic significantly(P0.01,q=4.97,q=7.42).Conclusion TNF-α plays an important role in radiation-induced lung injury.RhTNFR:Fc could suppress the inflammatory response and radiation-induced lung injury effectively by decreasing the levels of TNF-α.