Abstract:Objective:To observe the effect of the Yiqi Huoxue recipe on the expression of endothelin(ET-1)/interferon-γ(γ-IFN) in radiation-induced lung injury model rats. Method: 66 Wister rats were randomly divided into irradion plus Chinese herbs group (Yiqi Huoxue Recipe group),the purely irrdiated group(model Group),normal contorl group. From the exposure day, the Yiqi Huoxue Recipe group received ig Yiqi Huoxue Recipe 10 g·kg-1, the model Group and the contorl group received ig distilled water 10 g·kg-1 everyday,utill the rats were killed. At the 4th , 6th, 8th, 12th, 26th weekend after irradiation, six rats were randomly selected from the Yiqi Huoxue Recipe group and model group. At the same time, six rats in normal group were executed at the 8th weekend. After executing the rats, the serum and right lung tissue were collected for examination. Result: The expression and serum levels of the ET-1 in Yiqi Huoxue Recipe group were lower than those in model Group(P<0.05). γ-IFN began to decrease at the 4th week, and drop at the 12th week and rose again by the 26th week. The expression and serum levels of γ-IFN in Yiqi Huoxue Recipe group were higher than those in model group(P<0.05). Conclusion: Yiqi Huoxue Recipe can regulate and control the expression and secretion of ET-1,γ-IFN, and has good effect on the prevention of radiation-induced lung injury.