Change of Cytochrome Oxidase Expression in Type Ⅱ Alveolar Epithelial Cell of Rats Exposed to Hyperoxia / 实用儿科临床杂志

ABSTRACT

Objective To observe the expression of mitochondrial encoding cytochrome oxidase subunitⅠ(COXⅠ) and subunitⅡ(COXⅡ) in type Ⅱalveolar epithelial cell(AEC Ⅱ) of rats exposed to hyperoxia and explore the role of COXⅠand COXⅡ in hyperoxia-induced lung injury.Methods AECⅡ were gained by primary culture from 19-days fetal rats lung.After purified,AECⅡ were randomly assigned to hyperoxia group and air group.Hyperoxia group was flushed the flake with 950 mL/L O2 and 50 mL/L CO2 at 3 L/min for 10 min,then sealed.Both groups were in CO2 culture chamber(37 ℃,50 mL/L CO2).After 6,12 and 24 hours of exposure,AECⅡ were harvested and extracted for total RNA.COXⅠand COXⅡ mRNA were detected by reverse transcription polymerase chain reaction(RT-PCR).The results were analyzed by SPSS 12.0 softwore.Results Compared with air group,COXⅠmRNA expression in hyperoxia group increased significantly at 6 hours(t=3.832 P=0.019) and 12 hours(t=10.431 P=0),respectively,then decreased to the equivalent level in 24 hours(t=0.360 P=0.731).Compared with air group,COXⅡmRNA expression in hyperoxia group increased significantly at 6 hours(t=2.795 P=0.035),then decreased to the equivalent level at 12 hours(t=0.892 P=0.40) and 24 hours(t=2.018 P=0.071).Conclusions Exposure of hyperoxia up-regulate the expressions of COXⅠmRNA and COXⅡmRNA in AECⅡ,which may be a protective mechanism of hyperoxia-induced lung injury.