ObjectiveTo establish paraquat (PQ)-induced acute respiratory distress syndrome (ARDS) mice model via gavage, in order to simulate oral adminitration in clinical situations.MethodsSeventy-eight 6-8-week-old, specific pathogen free female C57 mice were chosen in this study. The mice were randomly divided into the control group (n=6) and the PQ model group(n=36); the mice in the latter group were randomly divided into 6 poisoning model subgroups further, with 6 mice in each, to find out the suitable concentration of PQ to establish stable ARDS model. The mice in the control group were given phosphatebuffer saline (PBS) by gavage, 200 μL per mouse; while the mice in the 6 poisoning model subgroups were given PQ with varies doses of 3, 10, 30, 100, 150, 300 mg/kg respectively by gavage. The clinical manifestations were observed for 7 days, and the ratio of lung wet/dry (W/D) was measured. After the suitable concentration of PQ for stable ARDS mice model was found, the other 36 mice were randomly divided into the controlgroup and the poisoning model group, both were divided into 4 subgroups, according to different observation point in time (1 day and 2, 3, 4 days after PQ gavage). The mice in the 4 control subgroups (n=3) were given PBS by gavage, 200 μL per mouse; while the mice in the 4 poisoning model subgroups (n=6) were given PQ with the suitable concentration for ARDS mice model by gavage. Pathological manifestations by Haematoxylin-Eosin staining and lung injury score were observed and analyzed.ResultsThe mice began to die at the PQ dosage of 150 mg/kg; while the death rate was stable at 300 mg/kg. On the 2nd and 4th day after PQ gavage, lung W/D was 5.335, 6.113, and 5.525, and 6.403, respectively in the mice in 150 and 300 mg/kg subgroup, which differed much from those in the control group (P<0.001). Congestion, edema, hemorrhage, alveolar structure damage, inflammation cells infiltration of lung tissue were observed, and lung injury score increased.ConclusionPQ-induced ARDS mice model by gavage is established successfully.