ABSTRACT
Objective To explore the expression of glutathione hormone (GSH) and γ-glutamyl cysteine synthetase (γ-GCS) in premature newborn rats exposed to hyperoxia,and to study antioxidant role of GSH and γ-GCS in hyperoxia-induced lung injury.Methods One-day old preterm SD rats were divided randomly into 2 groups:hyperoxia group and air group.Newborn rats in hyperoxia group were continuously exposed to oxygen(oxygen ＞ 850 mL/L),and newborn rats in air group were exposed in room air.After 1,7,14 days of exposure,the preterm SD rats of 2 groups were killed,and whole lung of these rats were isolated.GSH and γ-GCS of pulmonary tissue homogenate were detected by double antibody sandwich enzyme linked immunosorbent assay (ELISA).Bicinchoninic acid (BCA) was used to detect GSH protein in lung tissue homogenate.Total lung RNA was extracted and γ-GCS mRNA was detected by reverse transcription polymerase chain reaction.Results 1.The results were detected by ELISA method and BCA method,compaired with air group,the expression of GSH protein in lung tissue induced by hyperoxia was significantly increased after 1,7 days of exposure(all P ＜ 0.05),but the expression of GSH became significantly weak after 14 days of exposure (P ＜0.05).2.The expression of γ-GCS mRNA and protein level were significantly increased in 1,7 days (all P ＜0.05),but the general tendency decreased after 14 days of exposure,the expression of γ-GCS mRNA became stronger than its expression after 14 days of air group,both were no significantly different(P ＞0.05).Conclusions The changes of GSH and γ-GCS in the lung of premature SD rats induced by oxidation outbreak participate in the development of hyperoxia-induced lung injury,the activity of γ-GCS may be increased by hyperoxia,and alleviate hyperoxia lung injury in premature rats through antioxidation of GSH.