摘要
为探讨脊髓损伤时血脊髓屏障的破坏和小胶质细胞被激活两者之间的关系,本实验用大鼠脊髓挤压伤模型进行了研究。将成年雄性SD大鼠64只,随机分为对照组及脊髓挤压伤后0h、8h、24h、72h、1w、2w、4w等8组。分别以HE染色观察病理变化,小胶质特异性标记物OX-42的免疫荧光组化染色观察小胶质细胞,股静脉伊文思蓝注射观察血脊髓屏障的变化。结果显示,脊髓损伤面积在伤后8h组明显扩大,72h达顶峰,1w组时面积回缩并维持到实验最后(4w)。在伤后24h组可观察到活化的小胶质细胞,其后一部分迁移入损伤区内,吞噬坏死组织,变成巨噬细胞。至4w时,HE染色切片上仍可在伤区内见到小胶质巨噬细胞。伤区外活化的小胶质细胞仍可见于伤后4w。伊文思蓝不能通过正常的血脊髓屏障,脊髓挤压伤后即可进入脊髓,分布于损伤区及其邻近。至1w时脊髓内已无伊文思蓝,血脊髓屏障恢复正常。此现象与脊髓伤后活化的小胶质细胞长期存在的事实不一致。活化的小胶质细胞可损坏血脊髓屏障,血脊髓屏障在脊髓挤压伤后1w已恢复,而活化的小胶质细胞却可在伤后长期存在,说明单纯激活的小胶质细胞不足以破坏血脊髓屏障。
To study the relationship between the destruction of blood spinal cord barrier （BSCB） and the activation of microglia cells, we used spinal cord crushing as a model. Sixty-four adult SD rats were used, which were randomly divided into normal control, 0 h, 8 h, 24 h, 72 h, 1 w, 2 w and 4 w groups. Sagittal frozen sections were cut and stained with HE for examination of the pathology, and immunoflu- orescent wistachemical method was used to stain OX-42, marker for microglia cells. Evens Blue was injected via the femoral vein for detecting the changes of the BSCB. The area of the injury increased significantly at the 8 h group, reached its peak at 72 h group, found declined at 1 w group and remained stable through the end of this study （4 w）. Activated microglial cells started to appear at 24 h group. Later, a number of the microglial cells migrated into the lesion and became macrophages for removal of the necrotic debris. At 4 w HE sections there were still remains of microglial phagocytes. The activated astrocytes at the vicinity of the lesion could be identified and is know to stay there for a long tine thereafter. Evens blue can not pass through the normal BSCB. At 0 h it appeared densely at the lesion site and its vicinity. At 1 w group it could no more be detected in the spinal cord, the BSCB had fully recovered. There was a prominent mismatch between the time of the presence of microglial phagocytes and that of the impaired BSCB. The activated microglia is known to secrete substances that are harmful to the BSCB ; the BSCB resumes its integrity at 1 w ; the activated microglia cells remained for a far longer time after injury. The result of this study showed that the activated microglial alone is not enough to disrupt the BSCB.
出处
《神经解剖学杂志》
CAS
CSCD
北大核心
2008年第2期113-118,共6页
Chinese Journal of Neuroanatomy
基金
国家重点基础研究计划(2003CB515301)
陕西省社发攻关项目资助(2006K15-G1)
关键词
脊髓损伤
血-脊髓屏障
小胶质细胞
大鼠
伊文思蓝
spinal cord injury, blood spinal cord barrier, microglial cell, rat, Evans Blue
