ObjectiveTo investigate the effects of short-time hyperoxia ventilation on lung tissue and pulmonary surfactant proteins C and D (SP-C and SP-D) in rats.MethodsSixteen male Sprague-Dawley rats were randomly divided into two groups (n=8): hyperoxia group (FiO2=0.90), air group (FiO2=0.21). Tracheal intubations were administrated after anesthesia, and rats in two groups were exposed hyperoxia or air ventilation for 4 h. At the same time, carotid artery blood gas was analyzed after 2 h and 4 h of ventilation, then oxygenation index (OI) was calculated. Four hours later, the anterior lobe of right lung was taken to observe the pathological change and the injury level was scored. The middle lobe of right lung was prepared for making tissue homogenate, and the remaining part of the lung was used to measure the wet/dry weight (W/D) ratio. The bronchoalveolar lavage fluid (BALF) was prepared in left lung. The content of SP-C and SP-D were detected in lung tissue homogenate and BALF by ELISA.ResultsComparing with hyperoxia group, the arterial partial pressure of oxygen, lung histopathology score and lung W/D ratio in air group were significantly increased (P<0.05), but OI, the content of SP-C and SP-D in lung tissue homogenate and BALF were significantly decreased (P<0.05).ConclusionHyperoxia ventilation for 4 h in rats can cause lung injury histologically, and reduce the concentration of SP-C and SP-D apparently in the lungs.