Effect of erythropoietin on cognition and neuron apoptosis in CA1 region of hippocampus in vascular dementia rats / 中华老年医学杂志

ABSTRACT

Objective To explore the effect of erythropoietin (EPO) on cognition and neuron apoptosis in CA1 region of hippocampus in vascular dementia (VaD) rats.Methods 54 Wistar rats were randomly divided into three groupssham control group,VaD group,VaD+ EPO group (n=18,each).The bilateral common carotid arteries of Wistar rats were permanently ligated to establish VaD models.Spatial study and memory were observed by Y maze test at 4,8 and 12 weeks after operation.Neuron apoptosis in CA1 area of hippocampus was measured by terminal deoxynucleotidyl-transferase (TdT) mediated dUTP-biotin nick end labeling (TUNEL) method.The protein and mRNA expressions of Bcl 2 and Bax in CA1 region of hippocampus were detected by immunohistochemistry and RT-PCR at 4,8,12 weeks after operation.Results Compared with VaD group,the VaD+ EPO group had better performances including less error reaction times and shorter total reaction time in Y-maze (both P＜0.05) at 4,8,12 weeks after operation.The apoptotic neuronal cells in CA1 region of hippocampus was decreased in VaD+ EPO group than in VaD group at 4,8,12 weeks after operation [(10.50±±2.43) vs.(20.50±± 3.29),(23.92±±3.18) vs.(33.58±3.48) and (36.92±4.10) vs.(54.17±4.26),t=4.23,3.54,5.05,P=0.013,0.024,0.007,respectively].The Bcl-2-positive cells and Bcl-2 mRNA expression were increased,and the Baxpositive cells and Bax mRNA expression were decreased in VaD+ EPO group than in VaD group (all P ＜0.05).Conclusions Erythropoietin can improve cognitive function by inhibiting neuron apoptosis through regulation of Bcl-2 and Bax expression in CA1 region of hippocampus.