Prevention effect of ulinastatin on radiation-induced lung fibrosis in rats

Objective To evaluate the effects of ulinastatin on radiation-induced pulmonary fibrosis in Sprague-Dawley(SD) rats and changes of laminin (LN) and hydroxyproline (Hyp) in radiation-induced pulmonary fibrosis. Methods One hundred female SD rats were randomly divided into three groups:group without irradiation or ulinastatin(group C), group treated with ulinastatin after radiation(group U), group only received thoracic irradiation(group R). Whole lungs of rats in group R and group U were irradiated with a total dose of 25 Gy by linear accelerator. The rats were sacrificed on 7, 15,30, 60, 90,150 days after irradiation. Radioimmunity was used to determine LN. Colorimetric assay was used to detect the protein level of Hyp. Results Hyp and LN levels significantly increased, severe inflammatory reaction and pulmonary fibrosis developed in rats only receiving thoracic irradiation,however,administration of ulinastatin prevented the inflammatory process and pulmonary fibrosis. Conclusions LN and Hyp play an important role in radiation-induced lung fibrosis,which could be prediction of radiation-induced lung fibrosis. Ulinastatin plays a protective and regulative role on pulmonary fibrosis of rats, which may serve as a novel therapeutic strategy. Key words: Laminin; Hydroxyproline; Ulinastatin; Lung; Radiation