大鼠脊髓损伤后趋化因子受体4时空分布与意义

Temporal and spatial distributions of CXC chemokine receptor 4 after spinal cord injury in Wistar rats

目的观察Wistar大鼠脊髓损伤后，脊髓组织中趋化因子受体4（CXCR4）表达变化，探讨大鼠脊髓损伤后CXCR4在修复脊髓损伤中的作用。方法Wistar雌性大鼠80只，使用改良的ImpaetormodelII法制作大鼠脊髓损伤模型，据取材时间分为8组（术后1、2、3、4、7、14、28d与对照组，n=10）。分别使用苏木素一伊红（HE）染色及免疫组织化学法染色观察脊髓组织中CXCR4表达变化。结果大鼠脊髓损伤后，脊髓灰质中的神经元、胶质细胞、巨噬细胞和室管膜细胞均有CXCR4表达量的增多，神经元与巨噬细胞较神经胶质细胞更为显著。损伤中心的阳性细胞数量大于损伤头端与尾端的阳性细胞数量。脊髓灰质中CXCR4阳性细胞数量明显多于白质。大鼠脊髓损伤后24h即有CXCR4表达增多（145．00±3．46）／mm2，第3天脊髓灰质中CXCR4阳性细胞达到高峰（181．50±6．73）／mm2。结论大鼠脊髓损伤后，脊髓组织中CXCR4表达发生变化，并有时间和空间的分布特点。

Objective To investigate the temporal and spatial distributions and the role of CXC ehemokine receptor 4 （ CXCR4 ） in the process of recovery after spinal cord injury （ SCI ） in Wistar rats. Methods Adult female Wistar rats （ n = 80） were randomly divided into eight groups ： the groups of 1,2, 3, 4, 7, 14, 28 days after SCI and control group （n = 10 each）. Immunohistoehemieal technique and he- matoxylin-eosin staining technique were used to examine the changes of CXCR4 temporal and spatial distri- butions in the spinal cord of Wistar rats. Results After SCI in rats, the expression of CXCR4 in neurons, glial cells, macrophages and ependymal cells in spinal cord gray matter was increased, especially in neu- rons and macrophages. The number of the CXCR4 positive cells near the injury site was significantly greater than that in the rostral and caudal regions, while the gray matter contained more CXCR4 positive cells than white matter. Twenty-four h after SCI in rats, the expression of CXCR4 was increased （ 145 ＋ 3.46） /mm2 , and on the 3rd day, the CXCR4 expression in the spinal cord gray matter reached the peak I （ 181.5 ＋ 6. 73 ）/mm2 ]. Conclusion CXCR4 was widely expressed and presented characteristics of temporal and spatial distributions after SPI in rats.