ObjectiveTo explore the effects of different concentrations of sevoflurane on hyperoxia-induced lung injury in rat.MethodsThe 72 SD rats were randomly divided into control group C (n=12); sevoflurane inhalation group S, group S contains 5 subgroups (n=12) S0, S1.0, S1.5, S2.0, S2.5. Group C wasn’t given any treatment, rats in group S were inhaled 95% oxygen for 48 hours to establish a hyperoxia-induced lung injury model. then rats in each subgroup inhaled sevoflurane at different concentrations of 0%, 1.0%, 1.5%, 2.0% and 2.5% for 1 h respectively, rats in group C were breathe air freely. At the two time points which include inhaled 95% oxygen for 48 hours, and sevoflurane was inhaled for 1 h, blood was collected by the abdominal aorta, then arterial blood was used for blood gas analysis; using enzyme linked immunosorbent assay for the detection of serum tumor necrosis factor (TNF) -α and interleukin (IL) -8 and IL-6 concentration; HE staining was carried out in the right lung, and the pathological changes of lung tissue were observed under light microscope; Wet to dry ratio (W/D) of the left lung was taken.ResultsAfter inhalation of 95% oxygen for 48 hours (T1): compared with the group C, group S of arterial blood gas results suggested that the PaO2 value decreased, PaCO2 value increased. The degree of lung tissue injury and the pathological score, TNF-α, IL-8 and IL-6, W/D content increased significantly (P < 0.05), there was no significant difference between the S0 to S2.5 groups; After treatment with sevoflurane for 1 h (T2): compared with the group C, group S of arterial blood gas results suggested that the PaO2 value decreased, PaCO2 value increased. the degree of lung tissue injury and the pathological score, TNF-α, IL-8 and IL-6, W/D content increased significantly (P < 0.05); Compared with before sevoflurane treatment, the PaO2 value increased, PaCO2 value decreased, TNF-α, IL-8 and IL-6, W/D content decreased, pathological score decreased in group S1.0 to S2.5 (P <0.05), but there was no significant difference in group S0; After treatment with sevoflurane, compared with S2.0 group, the PaO2 value decreased, PaCO2 value increased, TNF-, IL-8 and IL-6, W/D content increased, pathological score increased in the group S1.0 and S1.5 (P < 0.05), but there was no significant difference in group S2.5.ConclusionSevoflurane can effectively reduce the degree of lung injury caused by hyperoxia in rats especially when the concentration is 2%.