中文摘要：

目的研究血管内皮祖细胞（endothelial progenitor cells，EPCs）移植在损伤血管再内皮化及抑制新生内膜增生中的作用。方法大鼠脾源性单个核细胞贴壁培养法定向扩增EPCs，检测其内皮细胞特性。通过尾静脉将EPCs移植到颈动脉内皮损伤的大鼠体内。10只大鼠行偶氮蓝染色，观察内皮损伤血管段再内皮化情况；其余大鼠于术后14d处死，行病理学观察。结果脾源性单个核细胞体外可诱导出内皮祖细胞，表现为表达内皮细胞特异性标志。EPCs移植组损伤血管57％不被偶氮蓝着染，而球囊损伤组损伤血管几乎完全被偶氮蓝染成蓝色。球囊损伤＋EPCs移植组在球囊损伤2周后血管新生内膜增生明显减轻，血管腔狭窄程度显著减轻。球囊损伤＋EPCs移植组新生内膜与中膜比值显著低于单纯球囊损伤组及M199组。球囊损伤＋EPCs移植组PCNA阳性表达细胞较单纯球囊损伤组及M199组明显减少。结论EPCs参与损伤血管的再内皮化过程。增加循环EPCs数量可以促进损伤血管的再内皮化，抑制血管平滑肌细胞增殖，减轻新生内膜增生程度。

英文摘要：

Objective To investigate the feasibility of transplanting EPCs in vascular endothelium repair after vascular injury. Methods EPCs from spleen were isolated using a Ficoll density gradient centrifugation, and cultured in fibronectin-coated plate in M199 medium supplemented with 20% fetal bovine serum and 50 ng/ml vascular endothelial growth factor （VEGF）. The endothelial characteristics of EPCs were identified by immunologic cell chemical staining and fluorescent labeling. After induction of arterial injury in all 40 Wistar rats, 15 rats received intravenous injection of spleen-derived EPCs （2 × 106） through tail vein immediately after arterial injury and again 24 hours later, 10 control rats received a corresponding amount of M199 medium. Thirty minutes before sacrifice, 5 rats that only underwent arterial injury and 5 rats of EPCs injection received Evan blue intravenously. The morphology of arterial intima and media was studied by optical microscopy and image analysing system. Results The adherent cells were considered as EPCs that had spindle shape and form blood-land-like structures during development. They also gave rise to vessel-like cord structures. The adherent cells had many endothelial characteristics. They were von Willebrand Factor positive and could endocytose AcLDL and bind to UEA-I. The neointima/media area ratio in EPCs transplantation rats was obviously reduced than that in only arterial injury rats and M199 rats [ （0.82 ± 0.09 ） vs （1.52± 0.21 ）, （1.48 ± 0.19 ）, P 〈0. 01 ]. The cells positive for PCNA expression were evidently decreased as compared with only arterial injury rats and M199 rats [（19.25±3.96） vs （31.42±5.23）, （29.37±3.16）, P〈0.05]. Conclusion EPCs incorporated into the process of injured carotid reendothelialization. EPCs transplantation induced increase of the circulating EPCs, accelerated the process of endothelial repair and reduced neointima formation.