局部连续应用神经生长因子对周围神经修复与再生的影响

Effect of nerve growth factors continuously administrated in local part on perip heral nerve repair and regeneration

目的:探讨神经生长因子(nevergrowthfactor,NGF)局部连续给药对周围神经损伤后的修复与再生的影响。方法:SD大鼠48只,分4组;A组采用术后局部连续注射NGF0.3μL3周。B组:手术同侧腓肠肌处连续肌肉注射NGF0.3μL3周。C组:于术中单次给予NGF0.3μL于吻合处。D组:实验用生理盐水代替NGF。术后2,4,6,8周进行动物行为学观察,光镜观察,8周时行图像分析、神经电生理检测、电镜观察、辣根过氧化物酶标记逆行追踪观察脊髓前角运动神经元的标记情况。结果:神经电生理检测发现,A组和B组神经传导速度快、潜伏期短,C组和D组神经传导速度慢、潜伏期长(F=27.775,P<0.05)。光镜观察见,A组和B组再生的有髓神经纤维髓鞘较厚、直径较大、数量多、排列规则,再生良好,均优于C组和D组(F=5.53,P<0.05)。电镜观察见A组和B组有髓神经纤维髓鞘较厚、直径较大、C组和D组有髓神经纤维髓鞘较薄,直径较细。辣根过氧化物酶标记表明各组均见辣根过氧化物酶标记的前角运动神经元,但A组和B组的数目优于C组和D组。结论:①NGF局部连续给药具有明现的促进周围神经损伤后的修复与再生作用。②NGF局部连续给药优于局部单次给药。③半槽式硅胶管放置简单,取出方便,克服了晚期硅胶管对神经生长的不利影响。

AIM:To investigate the effect of nerve growth factors(NGF) administrated cont inuously locally on the peripheral nerve repair and regeneration after neural in jury. METHODS:A total of 48 SD rats were randomly assigned into four groups of 12 r ats each.Group A:NGF at a dosage of 0.3 ì L was injected locally in succession for 3 weeks post operation;Group B:0.3 ì L NGF was injected continuously into g astrocnemius muscle for 3 weeks;Group C:the injection of 0.3 ì L NGF was admini strated into stoma site once only;Group D:the rats were injected with normal sal ine instead of NGF.The specimens were obtained at 2,4,6,8 weeks for the observat ion of animal ethology and optical microscopy.Imaging analysis,neuroelecrophysio logy,electron microscope observation and horseradish peroxidase(HRP) labeling we re performed to observe the frontal horn motoneuron labeling at 8 weeks. RESULTS:Neuroelectrophysiological detection showed that group A and B had a f ast nerve conduction velocity(NCV) and a short latency, and by contraries,there was a slow NCV and a long latency(F=27.775,P< 0.05). Under optical microscope, a great amount of myelinated nerve fibers in the groups A and B arranged in order with thick and wide myelin sheath under a good growth condition better than tho se in the groups C and D(F=5.53,P< 0.05). Under electron microscope, the groups A and B had myelinated nerve fibers with thicker and wider myelin sheath as comp ared with those of the groups C and D.HRP labeling indicated that frontal horn m otoneurons labeled with HRP were found in all the four groups,but the number of labeled neurons were more in the groups A and B. CONCLUSION:Continuously local administration of NGF plays a better role in pr omoting peripheral nerve repair and regeneration,as compared with once local adm inistration.Semi-chamfer silica gel tube is easy and comfortable to be placed and taken,which overcomes the impact of later silica gel tube on nerve growth.