Experimental Study Of Erythropoietin (EPO) On Protecting Mechanism Of The Rat Brain After Cerebral Ischemia And Reperfusion

Part one: Objective:1. To explore the effect of EPO pretretment on expression of Bcl-xl protein in hippocampal CA1 subregion in the modeled rat of brain ischemia and reperfusion.2. To explore the effect of EPO pretretment on release of CytC from mitochondrion to cytoplasm in hippocampal CA1 subregion in the modeled rat of brain ischemia and reperfusion.Methods:Transient global cerebral ischemia model was made by 4-VO technique. Male Spraque-Dawley rats were as the experimental objects, which were randomly separated into 3 of groups including Sham, Saline control and EPO-Pretreatment. At 3 hours before global cerebral ischemia, saline or EPO was respectively injected into the lateral ventricle of rat, with help of stereotaxic coordinates, upon the designed conditions. The Sham rats were only performed the incision on cervix but without any treatment on the arteries. Expression of Bcl-xl protein and changes of CytC were observed in hippocampal CA1 subregion at 24 hours after cerebral ischemia and reperfusion. Results:Expression of CytC and Bcl-xl protein in hippocampal CA1 subregion declined manifestly in saline group at 24 hours after cerebral ischemia and reperfusion. Hippocampal CA1 subregion showed the stronger expression of Bcl-xl protein in EPO group than in Saline group (P<0.01) . There was thestronger expression of CytC in hippocampal CA1 subregion in EPO groupthan in Saline group (P<0.01).Conclusions:1. Pretreatment of EPO could enhance the expression of Bcl-xl protein in hippocampal CA1 subregion in the modeled rat.2. Pretreatment of EPO could inhibite CytC release from mitochondrion to cytoplasm in hippocampal CA1 subregion in the modeled rat.Part two: Objective:1. To explore the neuroprotection mechanism of EPO on brain ischemia.2. To explore the effect of EPO pretretment on apoptosis in hippocampal CA1 subregion in the modeled rat of brain ischemia and reperfusion.Methods:Transient global cerebral ischemia model was made by 4-VO technique. Male Spraque-Dawley rats were as the experimental objects, which were randomly separated into 3 of groups including Sham, Saline control and EPO-Pretreatment. At 3 hours before global cerebral ischemia, saline or EPO was respectively injected into the lateral ventricle of rat, with help of stereotaxic coordinates, upon the designed conditions. The Sham rats were only performed the incision on cervix but without any treatment on the arteries. Apoptosis neurons in hippocamp CA1 subregion were observed at 72 hours after global brain ischemia. Results:Hippocampal CA1 subregion showed evident apoptotic neurons in Saline group, and there were less apoptotic neurons in EPO group than in Saline group(P<0.01). Conclusions:Pretreatment of EPO could reduce the neuronal apoptosis and protect neuron in hippocampal CA1 subregion in the modeled rat.