EXPRESSION OF HIF-1α IN THE BRAIN ISCHEMIC MODEL OF RATS

Objective To investigate the expression of hypoxia inducible factor-1α(HIF-1α) in the brain ischemic model of rats. Methods Healthy Wistar rats(n=84) were randomly divided into three groups,the sham-surgery group(SS+SS,n=4),the sham and middle cerebral artery occlusion(MCAO) group(SS+MCAO,n=40) and the ischemic preconditioning and MCAO group(IP+MCAO,n=40).A rat model of focal ischemic preconditioning was established via occlusion of middle cerebral artery.At day 1,3,7,4,and 21 after the preconditioning,another two hours of ischemia were given to each experimental animal.The pathology was evaluated by HE staining.The volumes of infarct area were measured,and the expression of the HIF-1α detected via immunohistochemical technique. Results The levels of HIF-1α expression in rats of IP+MCAO group at day 1,3,and 7 after the preconditioning were significantly higher than those of the SS+MCAO groups(t=2.449-9.898,P0.05). Conclusion The expression of HIF-1α is up-regulated,which may be one of the molecular mechanisms in the brain ischemic tolerance.