The protective effect of EPO on Alzheimer disease rat learning and memory injury and its effect on Bcl-xl protein expression in hippocampal CA1 subregion

Abstract

Objective To explore the protecting mechanism of erythropoietin (EPO) on learning and memory of Alzheimer disease (AD) rats. Methods The AD model was made by injected into rat hippocampal CA1 subregion with amyloid beta-protein(Aβ). Male Spraque-Dawley rats were as the experimental objects, which were randomly separated into 3 groups including Sham, Saline control and EPO treatment. After Aβ was injected into rats hippocampal CA1 subregion ,saline or EPO was respectively injected into the lateral ventricle of rats,with help of stereotaxic coordinates, upon the designed conditions. Hippocampal CA1 subregion Bcl-xl expression changes were observed 24 hours after the operation, and learning and memory abilities were checked 4 weeks after the operation. Results 24 hours after the operation Bcl-xl expression in the EPO group and the Saline group was less than the Sham control ,while Bcl-xl positive cells( 100.42 ± 12.43/field) in the EPO group were more than in the Saline group( 82.06 ± 19.68/field ) (P ＜ 0. 05 ). 4 weeks after the operation learning ability in the EPO group ( 20.38 ± 5.88 ) was better than Saline group ( 25.50 - 3.25 ) (P ＜ 0. 05 ), and memory ability in the EPO group (4.75 ± 1.75 ) was better than the Saline group(2.88 ± 1.55 )(P ＜ 0.05 ). Conclusion EPO could improve the learning and memory abilities in the model rats,and it could be related with EPO restraining Bcl-xl expression decreasing. Key words: Erythropoietin ; Amyloid beta-protein ; Alzheimer disease ; Bcl-xl ; Learning ; Memory ;