神经生长因子干预大鼠脊髓损伤模型白质轴突计数和运动功能恢复的变化

背景:有实验已证实多种神经营养因子具有促进损伤神经元存活、分化和轴突再生的作用,使损伤后的脊髓组织结构完整性能得到最大的保存。目的:观察神经生长因子对大鼠脊髓损伤后神经再生和运动功能的影响。设计:随机对照观察。单位:华中科技大学同济医学院附属协和医院神经内科。材料:选用30只成年健康雄性Wistar大鼠(同济医学院动物实验中心)。方法:实验于2004-01/2005-01在华中科技大学同济医学院附属协和医院神经内科完成。采用随机抽签法将大鼠分为治疗组和对照组,每组15只。①造模:应用改良Allen’s打击法致伤脊髓。②干预措施:造模后,治疗组大鼠给予蛛网膜下腔注射含1μg神经生长因子的生理盐水0.05mL,1次/d,共3周;对照组大鼠注射等体积的生理盐水,1次/d,共3W。③斜板试验:在造模前和治疗后3d和1,2,3周分别应用改良Rivlin法(斜板试验)测定大鼠运动功能值。④形态学观察:造模后2天和3周,分别取7只治疗组大鼠和8只对照组大鼠进行NF200免疫组织化学检测与轴突计数。主要观察指标:大鼠造模前、治疗后3d及1,2,3周斜板试验结果以及大鼠造模后2d和3周白质区轴突计数。结果:①治疗组大鼠脊髓损伤后斜板试验结果在术后1,2,3周时分别为(45.2±3.2),(51.2±3.8),(53.4±4.6)°,明显高于对照组(37.2±2.8),(42.6±3.5),(44.5±5.6)°,差异有显著性(P<0.05)。②治疗后3周,对照组白质内可见少量、散在不均匀的NF200着色点。治疗组白质内可见大量均匀的NF200着色点。治疗组大鼠脊髓损伤后3W白质内轴突计数明显高于对照组(363.6±34.2,187.5±32.1,P<0.05)。结论:神经生长因子对脊髓损伤后的神经再生有一定的促进作用,并有助于功能恢复。

Changes of axonal count of white matter and recovery of motor function induced by nerve growth factor in rats with spinal cord injury

BACKGROUND:Neurotrophic factors have been conformed to have the effects of promoting the survival, differentiation and axonal regeneration of the injured neurons, so that the structural integrity of the injured spinal cord can be reserved as much as possible.OBJECTIVE: To observe the effects of nerve growth factor (NGF) on the neural regeneration and motor function following spinal cord injury in rats.DESIGN: A randomized controlled observation.SETTING: Department of Neurology, Union Hospital affiliated to Tongji Medical College, Huazhong University of Science and Technology.MATERIALS: Thirty healthy adult male Wistar rats of common degree, were provided by the Experimental Animal Center, Tongji Medical College of Huazhong University of Science and Technology.METHODS:The experiment was carried out in the Department of Neurology, Union Hospital of Tongji Medical College,Huazhong University of Science and Technology. The 30 rats were randomly divided into NGF-treated group (n=15) and control group (n=15). ① T8 spinal injury was induced by the improved Allen method. ③ The improved Rivlin method (namely, slope test) was used to assess the motor function following spinal cord injury in rats before model establishment and at 3 days, 1, 2 and 3 weeks after treatment respectively. ④ At 2 days and 3 weeks postoperatively, 7 rats in the NGF-treated group and 8 rats in the control group were selated and the cross-sectional tissue(0.5 cm) of the injured spinal cord was removed, fixed in neutral formalin, dehydrated, and embedded with paraffin, and then cut into 5 μm sections.MAIN OUTCOME MEASURES:① The results of the slope test before model establishment and at 3 days,1, 2 and 3weeks after treatment respectively; ② Axonal count in white matter at 2 days and 3 weeks after model establishment.RESULTS:① The scores of slope test after spinal cord injury at 1, 2 and 3 weeks postoperatively in the NGF-treated group were obviously higher than those in the control group (45.2±3.2), (51.2±3.8), (53.4±4.6)°; (45.2±3.2), (51.2±3.8),(53.4±4.6)°, P ＜ 0.05].② At 3 weeks after treatment, a few dispersal and heterogeneous NGF200 spots were observed in the white matter of rats in the control group, but there were plentiful and symmetrical NGF200 spots in the NGF-treated group. The axonal count in white matter at 3 weeks following spinal cord injury in the NGF-treated group was obviously higher than that in the control group (363.6±34.2, 187.5±32.1, P＜ 0.05).CONCLUSION:NGF can promote the neural regeneration following spinal cord injury to a certain extent, and help to im prove the functional recovery.