Comparision on the protection of hippocampal neuron of rats in different frequency intraperitoneal injection of EPO within acute phase of cerebral ischemia

Objective To explore the best frequency of EPO administration to get more effective protection of hippocampal neuron of rats in early period of acute cerebral ischemia. Methods 80 male SD rats were randomly divided into 3 groups:normal group,ischemia-reperfusion group and treatment group. In addition to the normal group,the other two groups were made of cerebral ischemia-reperfusion model,meantime the treatment group was divided into three sub-groups. Among the various sub-groups,EPO administration (intraperitoneal injection) and the doses (3000 IU/kg) were the same,while the frequency of administration was different from each other. Rats of third-administration group accepted EPO at ischemic instantly,4h and 12h after ischemia-reperfusion,respectively. Twice-administration group,ischemic instantly,and 4h after ischemia-reperfusion. Once-administration group,only ischemic instantly. The brain tissues of ratsin ischemia-reperfusion group and treatment group were used for observation of histological morphology by HE staining and analysis of Bcl-2,Bax expression in hippocamp by immunohistochemical staining. Caspase-3 expression in hippocampus was determinated by Western Blot. Results Contrast to the model group,Bax expression was significantly decreased in the three sub-groups(P0.05). Compared to the model group,Bcl-2 expression was significantly increased in twice-administration group(P0.05). Contrast to the model group,expression level of Caspase-3 decreased significantly in twice-and third-administration group (P0.05). Conclusion Erythropoietin is able to inhibit apoptosis to protect the hippocampal neurons,and twice-administration group shows obvious advantages. Twice-administration might be close to the best delivery method.