Study on Rat Small Airway Epithelium Injury Induced by Lipopolysac-charide and Its Pathogenesis

To study rat small airway epithelium injury induced by lipopolysaccharide(LPS) . SD rats were randomly divided into three groups: LPS injection group (group L1, inject 100 fig/100 /ul LPS into rat airway); LPS injection group (group L2, inject 50 ug/100 ul LPS into rat airway) and control group (group C, inject 100 ul physical saline into rat trachea) .Observed dynamically rat small airway epithelium injury changes under LM and TEM. Analysed rat small airway epithelium cell TNFαmRNA and TNF receptor mRNA expression level changes by hybridizationin situ. Results showed that Group L1 and group L2' s pathologic changes were almost same. 2 days after LPS injection small airway epithelium cell were slight degeneration, 4 days after LPS injection, epithelium cells demonstrate obvious necrosis and small airway inflammation also became severe. Group L1 rat small airway epithelium cells TNF am RNA and TNF receptor mRNA were higher(P 0.01) than that of control group rats. In group L1 ,TNFαmRNA of 8 day were higher than that of 4 days( P 0.01), and TNF receptor mRNA of 4 days were higher than that of 2 days( P 0.01) .1. LPS can induce rat small airway epithelium cells obvious injury in vivo. 2. Small airway epithelium cells TNFαmRNA expression increase play a important role in epithelium cell injury induced by LPS.