Study on neovascularization in focal cerebral ischemia/reperfusion model in rats

Objective Researches have found that neovascularization which may contribute to neurologic recovery does exist in focal ischemia/reperfusion brain,and endothelial progenitor cells play important roles in new blood vessel formation.So we studied roles of circulating CD34+ monocytes and AC133+ cells in neovascularization after focal cerebral ischemia/reperfusion in rats.Methods Right middle cerebral artery suture occlusion model was used.65 adult SD male rats were randomly divided into 3 groups.They were control,sham-control and animal models which included 1-hour (1h),3h,6h,12h,24h,48h 3-day (3d),4d,7d,14d,28d reperfusion groups.After right middle cerebral artery occluded,the rats were suffered from ischemia for 2 hours,and then reperfusion was allowed for different time as mentioned above before decapitation.Circulating CD34+ cells were detected by cytoflowmetric analysis and cerebral AC133 antigen expression in 2d,3d,4d,7d reperfusion groups were tested by immunohistochemistry.Cerebral vessels were observed in 28d reperfusion group by FITC-dextran perfusion.Results 1.Reperfusion 28 days later,total cerebral vessel areas around infarct core in infarct hemisphere were more than those in contralateral hemisphere by 24.79%.2.Circulating CD34+ cells sharply decreased from 3 to 7 days and returned to basal values on the 14th day.3.AC133 antigen expression was only observed in endothelial cells in areas around infarct core in 4 days.Conclusion There was the phenomenon of neovascularization around infarct core in rat MCAO models.Circulating CD34+ progenitor cells and AC133 antigen might take part in vessel repair and neovascularization in rat MCAO models.