Objective: To investigate the role of lung fibroblast activation in radiation-induced lung injury.
Methods: Thirty-five male Wistar rats were exposed to a single-dose 30 Gy irradiation of the right hemithorax or sham right lung irradiation. At 1, 7, 14, 28, 56 or 84 days after the irradiation, the rats were sacrificed for examination of alpha-smooth muscle actin (alpha-SMA) expression in the bilateral lung tissues using immunohistochemistry.
Results: alpha-SMA expression in fibroblast increased significantly in the out-field and in-field lung tissues within 24 h after irradiation after the irradiation (P<0.001).
Conclusion: Activation of the lung fibroblasts occurred within 24 h after irradiation and found in ont-field and in-field lung tissues, suggesting that radiation-induced lung injury may not have an obvious latency.