大鼠局灶脑缺血病灶周围新血管生成的相关实验研究

目的本研究主要探讨大鼠局灶脑缺血病灶周围新血管形成现象,探讨外周血CD34+细胞和脑组织AC133抗原在新血管形成中的作用。方法将成年SD雄性大鼠随机分为:1.正常组,2.假手术组,3.动物模型组。分别取缺血再灌注1h、3h、6h、12h、24h、48h、3d、4d、7d、14d、28d共11个观察点。取前10个观察点外周血标本,采用流式细胞术检测单个核CD34+细胞平均荧光强度。采用免疫组化染色法检测48h、3d、4d、7d脑组织AC133抗原表达。对28d组进行脑血管荧光分布面积的检测。每个观察点5只大鼠,共65只大鼠,根据神经功能计分纳入实验。结果1.脑缺血再灌注28d梗死半球半暗带区域的血管荧光总面积较非梗死半球相似区域增加24.79%。2.大鼠脑缺血/再灌注3d外周血单个核CD34+细胞平均荧光强度明显降低,直到7d。14d恢复到基线水平。3.AC133抗原在再灌注4d梗死半球半暗带区域的血管内皮细胞表达阳性,3d、7d组无阳性表达。结论本研究证实大鼠脑缺血28天梗死半球半暗带区域的血管面积较非梗死半球增大。研究提示循环CD34+干细胞和AC133+细胞可能参与脑缺血损伤的血管修复和新血管形成。

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.