Abstract: BACKGROUND ＆ AIM: To investigate the changes of semicarbazide- sensitive amine oxidase(SSAO) activity in lipopolysaccharide-induced pulmonary inflammation. MATERIALS AND METHODS: 15 adult male New Zealand white rabbits were randomly divided into three groups with 5 rabbits in each, two model groups (A and B) and one negative control group.The rabbit pulmonary inflammation model was developed by inhalation of lipopolysaccharide (2 mg/kg). Group A and the control were sacrificed after 48 hours, HE-stained sections of the lung were examined for histopathological changes.Group B was monitored by clinical features, WBC, and the fluctuation of plasma SSAO activity was measured and a comparison was made on the indexes before and after the treatment with LPS. RESULTS: Based on the number of WBC in peripheral blood and lung tissue HE stain after the treatment, LPS induced significant acute lung injury. The SSAO activity fluctuated and correlated with pathological change. After the treatment, the SSAO activity peaked at 16 hour and then decreased to the lowest level at 48 hour. The peak and trough activities were significant ly/different compared to 0 hour before treatment(P<0.05 or P<0.01). CONCLUSION: LPS administered through trachea cannula could reliably lead to acute lung injury and induce regular fluctuation of plasma SSAO activity.

Key words: lipopolysaccharide, pulmonary inflammation model, semicarbazide-sensitive amine oxidase