The protective role of erythropoietin induced by hypoxic preconditioning on cerebral injury and cognition after global cerebral ischemia / 中国中西医结合急救杂志

ABSTRACT

Objective To observe the protective effects of hypoxic preconditioning(HPC) on the improvement of the cognitive dysfunction(learning and memory) and the damage in hippocampus induced by global cerebral ischemia/reperfusion(I/R) in CA1 and CA3 for 5 days in rats,and on the regulation of expression of erythropoietin(EPO) protein to approach the mechanism of the protection.Methods One hundred and twenty adult male Sprague-Dawley(SD) rats were divided into four groups randomly: sham group,I/R group,HPC24 group(hypoxia for 24 hours before I/R) and HPC48 group(hypoxia for 48 hours before I/R).Hang(motor function),passive avoidance and Morris water maze tests were carried out on the 5th day after I/R to measure the motor and cognition functions;hematoxylin-eosin(HE) staining was used to detected histopathological changes in hippocampus tissues;and the contents of EPO were tested by immunohistochemistry at 1 hour and 4 hours after I/R from hippocampus CA1 and CA3 regions.Results Hang,passive avoidance and Morris water maze tests showed that I/R can injure rat cognition;the improvement of cognition was marked in HPC groups, and it was shown that the effects were more significant in HPC48 group than those in the HPC24 group(P