Expression of HIF-1α in neonatal rats with hypoxic-ischemic encephalopathy (HIE)

Objective To get the message of expression of HIF-1α in neonatal rats with hypoxic-ischemic encephalopathy (HIE), so to find out the more effective method to treat HIE.Methods Twenty four neonatal rats aged 7d were divided randomly into two groups, normal control group and hypoxic-ischemic group with 12 rats in each. According to the time point, 12 rats of every group were further divided randomly into two groups including 1d and 3d, with 6 rats in each subgroup. The left common carotid artery of the neonatal rats in hypoxic-ischemic group was ligated. 1h later, they were subjected to inhalation of 8% oxygen for 2h. The expression of HIF-1α in the levels of protein and mRNA in brain tissues of the rats were determined with HE staining, immunohistochemical staining and RT-PCR.Results Neonatal rats in hypoxic-ischemic group behaved restlessness, cyanosis, deep and rapid breath, astasia, lethargy, irritation and spasm; There were focal pyknosis, fragmentation, dissymmetry, blur or disappearance of nucleoli,raritas of ground substance in left cerebral cortex;The expression of HIF-1αmRNA in brain tissue of hypoxic-ischemic group were higher than that in normal control group, especially hypoxic-ischemic group at 3d, but there was no statistic significance; HIF-1α positive cells were found in cerebral cortex and hippocampus. There were more HIF-1α positive cells in hypoxic-ischemic group(p=0.00)and mainly in vascular endothelial cells (VECs).Conclusion The expression of HIF-1α in brain tissue was up-regulated in neonatal rats with HIE, mainly in VECs.