Expression of Glial Fibrillary Acidic Protein in Brain Tissue of Newborn Rats with Hypoxic-Ischemic Brain Damage Induced by Progesterone Intervention

Objective:To observe the effect of progesterone on the expression of glial fibrillary acidic protein (GFAP)in brain tissue of neonatal rats with hypoxia-ischemia brain damage,and discuss the protective mechanism of progesterone thereof.Methods:Twenty four neonatal rats were randomly divided into three groups: sham-operated group,hypoxia-ischemia group and pretreatment group.Rats in hypoxic-ischemic group and pretreatment groups were subjected to left common carotid artery ligation,then were exposed to 80 mL/L oxygen and 920 mL/L nitrogen gas in 37 ℃ closed container for up to 2.5 h to establish hypoxic-ischemic encephalopathy(HIE) model.Progesterone was injected intraperitoneally into rats of pretreatment group respectively at 30 minutes before hypoxia.The same dose of solution was injected into the other two groups.All rats were killed at 24 hour after operation.The immunohistochemistry staining and RT-PCR were used to examine the expression of GFAP in brain of rats.Results:GFAP was expressed in rats of three groups.The positive staining cells of GFAP and the expression levels of GFAP were significantly higher in hypoxic-ischemic group than those of sham-operated group(P 0.05).The GFAP positive staining cells and the expression levels of GFAP were significantly lower in pretreatment group than those of hypoxic-ischemic group(P 0.01).Conclusion:The hypoxic-ischemic brain damage may induce significant increase of GFAP expression in brain tissue of neonatal rats.Progesterone can inhibit the increased of astroeyte induced by hypoxia-ischemia brain damage,which plays a protective role by anti-hypoxic-ischemic brain damage.