脊髓损伤大鼠内皮祖细胞与脊髓血管新生

背景：诸多脑损伤实验表明,改善损伤组织缺血缺氧有助于促进损伤组织的修复,并有保护神经功能的目的。目的：探讨挫伤型脊髓损伤后大鼠外周血中内皮祖细胞的变化及其与创伤灶周围早期血管新生情况的关系。方法：成年雄性SD大鼠60只,随机数字表法均分为实验组与对照组。实验组采用Allen’s原理制作脊髓损伤模型,对照组只行椎板切除暴露脊髓,不予打击致伤。分别于术前及术后3,6,24,48,72,168h取大鼠外周血,流式细胞仪检测外周血中内皮祖细胞数量。并于术前及术后1,4,7,14d处死大鼠取脊髓,采用血管内皮标志物CD31免疫组化染色方法观察创伤区血管的新生情况。结果与结论：两组大鼠外周血内皮祖细胞水平于伤后3h均有所下降,6h开始上升,24h达高峰,随后逐渐达稳定水平。实验组高峰值明显高于对照组。同时微血管数量呈逐渐增多的趋势。说明大鼠脊髓损伤后,外周血内皮祖细胞数量明显增加,内皮祖细胞参与血管新生和损伤组织的修复,最终促进神经功能恢复。

Correlation between endothelial progenitor cells and neovascularization following spinal cord injury in rats

BACKGROUND：Many brain injury experiments have demonstrated that improving ischemia and hypoxia in injured tissue helps to promote the recovery of tissue injury and protect neurological function.OBJECTIVE：To investigate the relationship of endothelial progenitor cells and early neovascularization following spinal cord injury in rats.METHODS：A total of 60 Sprague-Dawley rats were divided into experimental groups ruined by modified Allen＇s method and surgical controls that received laminectomy but did not receive a contusive injury.Peripheral venous blood samples were taken prior to surgery and at 3,6,24,48,72 and 168 hours after surgery,and the counts of endothelial progenitor cells were determined by flow cytometry.The rats were sacrificed on days 1,4,7 and 14.The morphological changes in neovascularization were observed,and the expression of CD31,a marker of vascular endothelial cell,was detected by immunohistochemistry.RESULTS AND CONCLUSION：The levels of circulating endothelial progenitor cells within the first 3 hours of injury were lower than normal subjects,but increased over time,and reached a peak around 24 hours post-injury at a level that was significantly higher than controls.The change in circulating endothelial progenitor cells was obviously correlated with the change of CD31 ＋ vessels in the region adjacent to the epicenter of the injury site.The results demonstrate a close correlation between an increase in circulating endothelial progenitor cells in response to spinal cord injury and angiogenesis in spinal cord injury rat spinal cord.They also suggest that the increase in circulating endothelial progenitor cells promotes the tissue recovery in spinal cord injury.