周围神经移植联合神经营养因子修复脊髓传导束的实验研究

The experimental study of repair of spinal tracts with peripheral nerve graft combined with neurotrophic factors

目的探讨周围神经移植联合神经营养因子修复脊髓传导束的可行性并观察其再生的情况。方法121只Wistar雄性大鼠被随机分成5组,A组(实验组,n=25):在T9水平横行切断脊髓并切除5mm,植入肋间神经和含酸性成纤维因子(acidicfibroblastgrowthfactor,aFGF)纤维蛋白凝胶;B组(水平对照组1,n=25):同法制备脊髓横断模型,断端间由含aFGF的纤维蛋白凝胶填充;C组(水平对照组2,n=25):同法制备脊髓横断模型,断端间植入肋间神经和不含aFGF的纤维蛋白凝胶;D组(水平对照组3,n=25):同法制备脊髓横断模型,断端间旷置;E组(空白对照组,n=21):仅行椎板切除术。通过BDA顺行神经示踪、FG逆行神经示踪、运动诱发电位(MEP)和大鼠BBB后肢运动功能评分,观察脊髓传导束再生的情况。结果A组在损伤区有BDA标记的神经纤维通过,在颈髓背角和腹侧角、脑干中缝核和红核、网状结构、前庭侧核以及在大脑运动皮层的第V层均发现FG标记阳性的神经细胞数。A组大鼠MEP的平均潜伏期和波幅以及BBB功能评分明显提高,与B、C和D组比较差异有统计学意义(P<0.01)。结论周围神经移植联合神经营养因子能部分修复脊髓传导束。

Objective To investigate the feasibility of repairing spinal tracts with peripheral nerve graft combing neurotrophic factors in rats following complete spinal cord transection.Methods One hundred and twenty-one male Wistar Rats were transection at T9 level of spinal cord, and randomly divided into five groups. Group A with spinal cord transection was underwent acidic fibroblast growth factor （aFGF） treatment and peripheral nerve grafts （n=25）; Group B： spinal cord transection was underwent aFGF treatment only （n= 25）; Group C： spinal cord transection was underwent peripheral nerve grafts only （n=25）; Group D： spinal cord transaction only （n=25）; and Group E： sham control （laminectomy only, n=21）. The locomotor behavior of all rats was analyzed by the BBB open field locomotor test over the six months of survival time. Motor evoked potentials （MEP） were used to evaluate axon growth across the damage site. Biotinylated Dextran Amine （BDA） and retrograde tracing with fluorogold were used to evaluate the presence of axons through the damage site after treatment. Results The presence of anterograde BDA labeling of corticospinal tract axons at the graft site and fluorogold retrograde labeling of neuron populations was found in motor cortex and in red nucleus, reticulospinal nuclei, raphe nuclei, and vestibular nuclei in Group A. The average latency and amplitude of MEP were improved significantly in Group C. The mean of BBB scores showed significant improvement in Group A. Statistical analysis indicated that Group A had significant improvement compared to Group B,C and D at 6 months post-surgery （P 〈 0.01）. Conclusion Peripheral nerve grafts and aFGF treatment facilitate the regrowth of the spinal tracts and improve hindlimb function in a spinal cord-transected rat model.