Hyperoxia increases the expression of lung heme oxygenase-1 in rat pups

Objective To investigate the effects of hyperoxia on the expression of lung heme oxygenase-1(HO-1) in rat pups.Methods 21-d-old male Sprague-Dawley rat pups were randomly divided into 5 groups: room-air control group and 12,24,48,72 hours hyperoxia groups.The rat pups were continuously exposed to oxygen(92%～94%) and normal atmosphere respectively.The left lung wet/dry weight ratio and the histological examination were performed.The expressions of lung HO-1 mRNA and HO-1 protein were also measured by RT-PCR and Western blot,respectively.Results The expressions of lung HO-1 mRNA in 12 hours hyperoxia group(0.350±0.043) and HO-1 protein in 24 hours hyperoxia group(0.455±0.046) were increased as compared to those in the normal atmosphere(0.263±0.037,0.280±0.044),and the increase was more significant with the longer hyperoxia exposure(P0.05,P0.01).Compared with the normal atmosphere control,the left lung wet/ dry weight ratio and the lung injury scores was significantly increased in 48 hours hyperoxia group and 72 hours hyperoxia group(P0.05,P0.01).Conclusion Hyperoxia can induce the increase of lung heme oxygenase-1 expression in rat pups.