ABSTRACT
Objectives To explore the effect of erythromycin on glutathione hormone (GSH) and γ-glutamyl cysteine synthetase (γ-GCS) in premature newborn rats exposed to hyperoxia, to study the intervention effect of erythromycin on hype-roxia-induced lung injury. Methods One-day old preterm SD rats were randomly divided into four groups:control group, eryth-romycin group, hyperoxia group, erythromycin+hyperoxia group. Hyperoxia group and hyperoxia+erythromycin group were continuously exposed to oxygen (oxygen concentration>0.85), control group and erythromycin group were in room air. Via cau-dal vein, the preterm rats was injected with erythromycin in erythromycin group and hyperoxia+erythromycin group, sodium chloride in control group and hyperoxia group daily. After 1,7,14 day(s) of hyperoxia (or air ) exposure, the preterm SD rats of four groups were killed, whole lung of these rats were isolated and histological changes were observed by hematoxylin-eosin (HE) staining, GSH andγ-GCS of pulmonary tissue homogenate were detected by double antibody sandwich enzyme linked im-munosorbent assay. Total lung RNA was extracted andγ-GCS mRNA was detected by reverse transcription polymerase chain re-action. Results The results showed that:After 1 and 7 day(s) of exposure, the expression of GSH、γ-GCS andγ-GCS mRNA in four groups showed significant differences(P<0.05). Among them, GSH expression in erythromycin + hyperoxia group was higher than that in the other three groups in 1,7,14 day(s) of exposure with significant differences (P<0.05);GSH expression in erythromycin+hyperoxia group and hyperoxia group reached the peak after 7 days of exposure. The expression ofγ-GCS andγ-GCS mRNA in erythromycin+hyperoxia group and hyperoxia group were higher than the other two groups after 1and 7 day(s) of exposure, the expression ofγ-GCS mRNA in erythromycin+hyperoxia group were higher than that of hyperoxia group with significant differences (P<0.05). Conclusions The expressions of GSH andγ-GCS in the lung of premature SD rats were abnor-mal by oxidation outbreak. Erythromycin may increase the activity ofγ-GCS, improve the anti-oxidation ability of GSH, and al-leviate hyperoxia mediated lung injury in premature rats.
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.
ABSTRACT
Measurements have been made of the enzymes associated with γ - glutamyl cycle viz, γ-glutamyl transpeptidase, γ-glutamyl cysteine synthetase, and 5-oxoprolinase in human fetal brain, liver and kidney over 12-36 weeks of gestation. γ-Glutamyl transpeptidase activity increases gradually with age. γ-Glutamyl cysteine synthetase and 5-oxoprolinase show biphasic pattern of development in human fetal brain. The data presented in this communication may indicate a relationship between γ-glutamyl cycle and amino acid transport.