关键词:  脑缺血；再灌注；细胞凋亡

Abstract:

Abstract:Objective To explore the dynamic expressions of apoptosis-related factors of Bcl-2,Bax and p53 in rats with cerebral ischemia-reperfusion injury,and to provide the experimental evidence for the neuroprotective mechanism in cerebral ischemia-reperfusion injury.Methods 52 adult male Sprague-Dawley rats were randomly divided into sham control group (n=12) and cerebral ischemia-reperfusion 2,3,6,8,12 h groups(n=8).Suture method was used to set up the middle cerebral artery occlusion (MCAO) and reperfusion model.The neuronal apoptosis of the MCAO brain tissues at different time points was detected by in situ terminal deoxynucleotidyl transferase labeling technique (TUNEL); the dynamic expressions of Bcl-2,Bax and p53 were detected by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry.Results The TUNEL staining results  showed that the apoptotic cells began to appear 2 h after reperfusion  in the surrounding area in ischemia-reperfusion group,and they were increased significantly at 6-12 h.The mRNA and protein expressions of Bcl-2,Bax and p53 tended to increase with the prolongaction of ischemia and reperfusion time.The cell morphology was relatively complete in the cells with high expression of Bcl-2 protein,and the cells with high expressions of Bax and p53 protein were severely damaged.The mRNA and protein expressions of Bcl-2 appeared earlier than Bax and p53.Conclusion Bcl-2 has a protective effect on nerve cells.Early regulation can promote the expression of Bcl-2 and reduce the expressions of Bax and p53,and it plays an important role in reducing the damage of nerve cells in the process of ischemia and reperfusion.

Key words: ischemia, reperfusion, apoptosis