CD44在大鼠脊髓半横断损伤后的表达变化

目的通过观察CD44在大鼠脊髓半横断损伤（hemisection of Spinal Cord Injury，hSCI）位点头尾段的表达，了解它与脊髓损伤的关系。方法免疫组化SP法检测大鼠脊髓半横断损伤后CD44的表达变化情况。制备大鼠脊髓损伤模型。SD大鼠随机分为假手术对照组和脊髓半横断损伤3天、7天和14天组。应用免疫组织化学和图像分析技术检测脊髓组织CD44的表达。结果CD44阳性产物主要定位于细胞外基质，神经元和神经胶质细胞的胞浆中也有分布。损伤后CD44的表达较对照组明显增多﹝P〈0.05﹞。结论脊髓半横断损伤后，表达增加的CD44参与损伤后轴突生长被抑制这一过程。

The Changes in the Expression of CD44 of Rat with Hemisection of Spinal Cord Injury

Objective To investigate the expression changes of CD44 in spinal cord in 3d, 7d and 14d following hemisection of spinal cord injury （hSCI）. Furthermore, to explore the relationships of CD44 and spinal cord injury. Besides, to offer the morphological datum for the research concerning the spinal cord repair. Methods 20 adult healthy Sprague-Dawley rats were randomly divided into sham-operated control group and day3, day7, dayl4 spinal cord injury groups. The spinal cords were hemisected between T9 and T10. The spinal cord of every rat was taken out from the rostral and caudal segments of lesioned areas. Then the tissue blocks were made into 25 μm frozen sections and the immunohistochemistry ABC method was performed on these sections. We respectively observe and count the number of CD44 positive cells in spinal cord for all groups, and the average OD （optical density） value of immunoreactant were detected with computer image analysis technique. Results CD44 positive products were mainly distributed in extacellular matrix and neurons and neuroglial cells in spinal cord for the control group. The number of CD44 positive ceils and its OD value of rostral or caudal part of injury site for the three spinal cord injury groups were all increased 0a〈0.05）. Conclusion The increased-expression CD44 may mutually play inhibitory effect on axon regeneration following SCI.