Expression of thioredoxin and thioredoxin reductase in hyperoxia-induced lung injury of newborn rats

Objective To investigate the changes and potential roles of the expression of thioredoxin and thioredoxin reductase in the premature Newborn rat lung exposed to hyperoxia.Methods On the first day after ddivery,the preterm SD rats were randomay divided into air group and hyperoxia group(both n=64).The rats were kined on day 4.7,10 and 14 respectively.Total RNA of lung was isolated and Trx and TR mR-NA expression levels were detected by reverse transcription polymerase chain reaction(RT-PCR).The sections of lung were stained with HE method in order to assess lung histologic changes and examine lung radical alveolar counts(RAC).Results Rats in hyperoxia group showed typical lung injury,which Was characterized by alveolitis and delay of lung development.Compared with air group.RACs were significantly decreased in hyperoxia group(P＜0.05).RT-PCR results showed Trx and TR mRNA expression levels in hyperoxia group markedly increased,peaking at day 10(1.444±0.142 vs 0.609±0.078,P＜0.01)and day 7(2.035±0.160 vs 1.325±0.164,P＜0.01)respectively.Conclusion Trx and TR expression could be induced by hyperoxia,which might play an importandy protective role in the development of hyperoxia-induced lung injury. Key words: Hyperoxia; Premature; Thioredoxin; Lung iniury