Expression of NF-kappa B and the effect of dexamethasone in brain of newborn rats with asphyxia.

【Objectives】 To observe the activation of nuclear factor-kappa B(NF-κB)and the effect of dexamethasone on NF-κB activity in brain of newborn rats with asphyxia.The aim of the study was to explore the effect of NF-κB signal pathway in neonat with asphyxia,so as to provide the experimental base for finding clinical treatment of asphyxia,in which NF-κB was taken as the target. 【Methods】 Newborn rats(7 days old) were randomly divided into three groups:control group,asphyxia group and DXM pretreatment group.The model of asphyxia was induced in asphyxia group and DXM pretreatment group.Immunohistochemical method was used to detect the activity of NF-κB p65 in the brain of the newborn rats,and hematoxylin-eosin-stained was also performed to observe the histological evidence of asphyxia in the brain. 【Results】 The activity of NF-κB p65 was stronger in the asphyxia group than that in the control group(P0.05),increased to the highest peak at 5 d;After DXM pretreatment NF-κB p65 activity became lower(P0.05);The neurons had histological evidence of apoptosis in asphyxia group.Histological evidence of apoptosis was also observed in DXM pretreatment group,but less intensely. 【Conclusions】 The results suggest that NF-κB may play an important role in brain injury with asphysia.DXM have some protective effects against the brain injury and that protection seemed to be related to inhibiting augmentation of NF-κB activity.