不同时间移植人脐血CD34+细胞可影响心肌梗死大鼠心功能及血管内皮细胞生长因子的分泌

背景：干细胞移植可以改善心脏功能，改善预后。 目的：观察不同时间经静脉移植人脐血CD34+细胞对心肌梗死大鼠心功能及细胞因子分泌的影响。 方法：结扎冠状动脉左前降支制备Wistar大鼠心肌梗死模型，于梗死后1，5，10 ，30 d经尾静脉注入0.5 mL人脐血CD34+细胞(实验组)或磷酸盐缓冲溶液(对照组)。 结果与结论：与对照组相比，梗死后5，10 d实验组大鼠左室射血分数明显升高(P < 0.05)，左室收缩末内径明显减小(P < 0.05)，左室后壁增厚率更高(P < 0.05)，毛细血管密度明显增加(P < 0.05)，且以梗死后10 d移植大鼠心功能改善效果最明显(P < 0.05)。梗死后10 d实验组心肌局部血管内皮细胞生长因子最高(P < 0.05)。说明大鼠心肌梗死后5，10 d经静脉移植脐血CD34⁺细胞可明显改善心功能，梗死后10 d移植血管内皮细胞生长因子分泌更多，血管生成更多，对心功能的改善更明显；同时说明脐血单个核细胞移植可能是通过增加血管内皮细胞生长因子分泌，提高毛细血管密度来改善心功能的。

Effects of CD34+ human umbilical cord blood cell transplantation in different time on cardiac function and vascular endothelial cell growth factor secrection in rats with myocardial infarction

BACKGROUND:Stem cells transplantation can improve the cardiac function in the patients with myocardial infarction (MI) and improve the prognosis. OBJECTIVE:To study the effects of intravenous transplantation of CD34+ human umbilical cord blood cells in the different times on cardiac functions and cytokine secretion in rats with MI. METHODS:MI model was established by ligation of the left anterior descending coronary artery in rats. The experimental group and control group were injected with 0.5 mL CD34⁺ human umbilical cord blood cells and phosphate buffered saline through caudal vein at 1, 5, 10 and 30 days after MI, respectively. RESULTS AND CONCLUSION:Compared with control group, the ejection fraction of left ventricular was significantly increased at 5 and 10 days after infraction (P < 0.05), the left ventricular end-diastolic dimension was significantly induced (P < 0.05), the left ventricular posterior wall thickening and the capillary density was improved significantly (P < 0.05) and the number of vascular endothelial cell growth factor in the experimental group was the most (P < 0.05), especially at 10 days after infraction, the cardiac functions were improved most obviously (P < 0.05). Intravenous transplantation of CD34⁺ cells could improve the cardiac function at 5 days and 10 days after MI. At 10 days after infraction, the secretion of VEGF was increased, the angiogenesis was increased, and the cardiac function improvement was most significant. Cord blood mononuclear cell transplantation may improve the cardiac function through the increase of VEGF secretion and capillary density.