Effects Of Erythropoietin On Improving White Matter Injury And Enhancing Neurogenesis In Newborn Rats With Hypoxia-Ischemic Brain Damage

Objective:To investigate the effects of recombinant human erythropoietin(RhEPO)on improving white matter injury and enhancing neurogenesis in newborn rats with hypoxia-ischemic brain damage (HIBD). Method:Ninety 7-day-old newborn SD rats were randomly divided into three groups:Sham operation group(n=30),control (normal saline NS) group (n=30), experiment(RhEPO)group(n=30). HIE model was established by ligation of the left carotid artery along with 2.5-hour 8% oxygen exposure in neonatal rats of the Control and experiment groups. The sham oneration group was not snbiected to hvnoxia-ischemia The experiment group received an intraperitoneal injection of recombinant human erythropoietin (rh-Epo, 1000IU/kg) at multiple time points after HIE in postnatal day 7 rats, while the other two groups received normal saline at the same time. In each group rats was randomly executed immediately, on the 7th and 14th day after the operation. In order to evaluate the effects of erythropoietin on improving white matter injury and enhancing neurogenesis in newborn rats with hypoxia-ischemic injury, the ratio of myelin basic protein(MBP) to neurofilament 200(NF-200) and DCX positive cells was examined by immunohistochemical staining and image quantitative analysis respectively on the 7th,14th day after the operation. Result:1.MBP/NF-200:The ratio of MBP to NF-200 in control group and experiment group were lower than that in sham operation group on 7th day significantly (P<0.01). The ratio of MBP to NF-200 in control group was lower than that in experiment group on 14th day significantly (P<0.05). The ratio of MBP to NF-200 in control group and experiment group on 7th day were lower than that in control group and experiment group on 14 day significantly (P<0.01).2. DCX positive cells:The number of DCX positive cells in control group and experiment group were higher than that in sham operation group on both 7th day and 14th day significantly (P<0.01). The number of DCX positive cells in control group was lower than that in experiment group significantly (P<0.01). The number of DCX positive cells in sham operation group and control group on 7th day were higher than that in sham operation group and control group on 14th day significantly (P<0.01). The number of DCX positive cells in experiment group on 7th day was lower than that in experiment group on 14th day significantly (P<0.01). By HE staining, the degree of damage in the hippocampal region of the experiment group decreased compared with the control group.Conclusion:1. Administration of RhEPO can improve the white matter myelin sheath injury in hypoxic-ischemic injury.2. Administration of RhEPO can enhance neurogenesis to exert neuroprotective effect.