环磷酸腺苷在大鼠脊髓背侧半切损伤修复中的作用

The role of cyclic AMP in repair of hemisection of spinal cord in rats models

目的观察在体内给入环磷酸腺苷(cAMP)对大鼠脊髓损伤修复中的作用.方法采用大鼠脊髓T10背侧半切伤模型,通过在脊髓损伤局部、大脑运动皮层、和蛛网膜下腔内给入cAMP,做组织切片免疫组化染色,观察损伤区局部神经丝(NF)、胶质纤维酸性蛋白(GFAP)、皮质脊髓束(CST)纤维、脊髓神经纤维及后肢运动功能评分(BBB).结果 cAMP在脊髓损伤局部和大脑运动皮层给入时,损伤区可见大量脊髓再生纤维,在蛛网膜下腔内给入时损伤区可见极少量皮质脊髓束纤维存在.cAMP组损伤区NF分布较多,GFAP较少.所有动物后肢运动在5～6周恢复正常行走,BBB评分的时间曲线在对照组和cAMP组之间没有明显区别.结论在体内给入cAMP能诱导大鼠脊髓损伤后神经再生.

Objective To study the role of cAMP in repair of hemisection of spinal cord in rats models. Methods Rats models of spinal cord hemisection were made and cAMP were injected once in the motor cortex or continuously input in the lesion area or in the subarachnoid cistern for 3 d. NFs, GFAP, CSTs and spinal axons in the lesion areas were observed by immunohistochemistry and hind limb movements were evaluated in BBB scales. Results Many regenerated axons were presented in the lesion areas in cAMP groups though no continuous long regenerated axons traversed the lesion area when cAMP was input in the motor cortex or in the local lesion area. In control group ,no regenerated axon were presented in the lesion areas. When cAMP was input in the subarachnoid cistern, only few-labelled CST axon survived and presented in the lesion area comparing no labelled CST axon presented in the lesion area. More NFs and less GFAP were distributed and extended in the lesion area in the cAMP groups. All the rats restored to normally walk 4-5 weeks after operations and no significance existed between cAMP groups and control groups comparing the BBB scales of hind limb movements. Conclusion cAMP injected in the brain cortex or continuously input in the lesion area can induce the axonal regeneration.