Effect of ulinastatin on tumor necrosis factor and interleukin-6 in rats with radiation-induced lung injury

Objective To observe the effect of ulinastatin on tumor necrosis factor(TNF-α)and interleukin-6(IL-6)in radiation-induced lung injury.Methods Severity-two female SD rats were randomly divided into 3 groups as control group,irradiation group and treatment group(administered with Ulinastatin).Rats in irradiation group and treatment group were irradiated with linear accelerator at a single dose of 25 Gy.After irradiation rats in treatment group were injected daily with ulinastatin at a dose of 100000 U-kg-1·d-1 for 7 days through caudal vein while rats in control group and irradiation group were injected with the same volume of saline.Rats were killed at 2 h,4,8 and 24 weeks.Samples of lung tissues were observed by using HE staining.Expression of TNF-α in lung was determined by Western blot and expression of IL-6 in serum was determined by ELISA.Data were analyzed by SPSS software.Results Expressions of TNF-α in lung and IL-6 in serum increased significantly after irradiated in irradiation group compared with control group,and it reached the peak at 4 weeks(q=5.63、6.21,P＜0.01).Though expressions of TNF-α and IL-6 in ffeatment group also increased compared with control group,the difference between irradiation group and treatment group was statistic significantly(q=4.97、7.42,P＜0.01).Conclusions TNF-α and IL-6 play an important role in radiation-induced lung injury.Ulinastatin could suppress the inflammatory response and radiation-induced lung injury effectively by decreasing the levels of TNF-α and IL-6. Key words: Ulinastatin; TNF-α; IL-6; Lung; Radiation