ABSTRACT
Objective: To investigate the effect of angiotensin-converting enzyme inhibitors (ACEI), captopril (Cap), on the serum levels of transforming growth factor β1 (TGF-β1) and tumor necrosis factor α (TNF-α) in mice after lung irradiation injury. Methods: Male C57/BL mice were divided into three groups: control group, right lung single irradiation group (10 Gy), and right lung single irradiation (10 Gy) plus Cap administration group. The blood samples were collected at 36 h, 7 d, 15 d, and 30 d after irradiation. The levels of TGF-β1 and TNF-α were evaluated with ELISA method. The right lungs were isolated and stained with HE for pathological examination at the same time points. Results: The average serum levels of TGF-β1 and TNF-α in single 10-Gy irradiation group were significantly increased at different time points compared with the control group. But they were significantly decreased at different time points in 10-Gy radiation plus Cap group compared with the control group. The results of analysis of variance showed that there was a significant difference among the factor of time, the factor of treatment, and the factor of interaction (P < 0.05). Pathological examination showed that acute inflammation was aggravated in single 10-Gy irradiation group. But there was no significant difference in lung injury score between 10-Gy irradiation plus Cap group and control group. Conclusions: Cap reduces the serum levels of TGF-β1 and TNF-α and prevents lung against radiation-induced injury.