Changes of Lung Injury Indices and Serum Inflammatory Factors in Mice with Endotoxemia Induced by Lipopolysaccharide

Objective To establish the endotoxemia model induced by lipopolysaccharide(LPS) in mice,and to observe the changes of lung injury indices and serum inflammatory factors.Methods The BALB/c mice were divided into two groups randomly,normal control group and LPS-induced model group.Each group was further divided into four subgroups by time control point.General symptoms were recorded.Histopathological changes in lung was observed and lung wet/dry weight were measured.Serum TNF-α and NO were measured by using radio immunoassay and nitrate reductase method.Results(1) Symptoms appeared at 30min after LPS injection on mice in LPS-induced model group and continued within 24h;pathological change was distinct in every time-control-point.The lung tissue pathological changes aggravated at 6h and continued within 24h.Lung wet/dry weight significantly increased in model group compared to that in controls.The levels of serum TNF-α and NO increased at 2h after LPS administration,peaked at 6h and 12h,then declined.The levels of serum TNF-α and NO sustained higher in model group than those in control group at 24h(P0.01).Conclusion 7mg·kg-1 LPS with intravenous injection can establish an ideal animal model of acute lung injury;uncontrolled expression of inflammatory mediators is one of an important mechanism in LPS-induced acute lung injury.