Changes of IL-8 Levels in Alveolar of Hyperoxic Lung Injury in Premature Rats

Objective To investigate the content of interleukin-8(IL-8)in pulmonary alveoli in preterm rats with hyperoxia-induced lung injury.Methods 120 preterm SD rats(6 hours after delivery)were divided randomly into two group: hyperoxia group(n=60)and air group(n=60).Pups in hyperoxia group were exposed to hyperoxia(FiO2900 ml/L)and those in air group were raised normally inhaling room air.Histological changes of the lungs were observed and the contents of IL-8 in bronchoalveolar lavage fluid(BALF)were measured by ELISA on day 1,3,5,10,14,respectively.Results The structure of pulmonary alveoli developed gradually with aged in air group.Vasodilatation and engorgement in small vessels,red blood cell in alveolar space and inflammatory cell infiltration in alveolar space and interstitial could be found from day 3 in hyperoxia group.Along with prolong exposure to hyperoxia,lung development was impaired and alveoli structure appeared reduction in the number of alveolar.IL-8 level in BALF increased significantly in hyperoxia group from day 3 to day 14 compared to age-matched,air group(P0.01 in each matched groups).Conclusion As an important inflammatory mediator,IL-8 contribute to the development of hyperoxia-induced lung injury.