周围神经移植联合aFGF治疗急性脊髓损伤的实验研究

The experimental study of treatment of acute spinal cord injury with peripheral nerve graft combined with aFGF

目的:探讨周围神经移植联合酸性成纤维细胞生长因子(aFGF)治疗大鼠脊髓损伤(SCI)的可行性及效果。方法:雌性Sprague-Dawley大鼠115只,随机分为4组。A组(自体肋间神经移植组,n=30):在T9水平横行切断脊髓并切除3mm,植入自体肋间神经;B组(自体肋间神经联合aFGF移植组,n=30):同法制备脊髓横断模型,脊髓缺损处植入自体肋间神经和含aFGF的纤维蛋白凝胶;C组(脊髓横断组,n=30):同法制备脊髓横断模型,断端间旷置;D组(椎板切除组,n=25):仅行椎板切除术。分别通过BBB后肢运动功能评分、体感诱发电位(SEP)及运动诱发电位(MEP)、生物素葡聚糖胺(BDA)顺行神经示踪及荧光金(FG)逆行神经示踪,观察大鼠SCI恢复情况。采用SPSS13.0软件行统计学分析。结果:术后70d时A、B、C、D组BBB后肢运动功能评分分别为11.9±1.42分、14.3±1.27分、0.6±0.51分、21.0±0.00分,各组间两两比较均有显著性差异(P<0.01)。术后90d时C组未引出SEP波形,A组SEP潜伏期和波幅分别是(62.7±2.18)ms和(1.70±0.07)μV,B组分别是(40.6±1.25)ms和(2.28±0.12)μV,D组分别是(10.1±0.65)ms和(6.86±0.19)μV,A、B、D三组间两两比较均有显著性差异(P<0.01)。C组未引出MEP波形,A组MEP潜伏期和波幅分别是(12.7±0.50)ms和(1.0±0.18)mV,B组分别是(9.2±0.20)ms和(1.3±0.13)mV,D组分别是(6.4±0.32)ms和(2.0±0.18)mV,A、B、D三组间两两比较均有显著性差异(P<0.01)。术后90d时,A组在损伤区有BDA标记阳性神经纤维通过,计数为(62.6±8.04)条,在颈髓背角、延髓薄束核和楔束核、网状结构、背侧丘脑腹后外侧核及大脑感觉皮层均发现FG标记阳性神经细胞,计数为(4086.9±182.58)个,B组分别为(81.0±4.62)条和(4979.3±489.43)个,D组分别为(158.6±9.03)条和(6214.1±423.98)个,C组在上述解剖区域未发现BDA标记阳性神经纤维和FG标记阳性神经细胞,A、B、D三组间两两比较均有显著性差异(P<0.01)。结论:单纯周围神经移植能部分恢复脊髓功能,联合aFGF则能更好地恢复脊髓功能。

Objective：To explore the feasibility and effect of the repair of spinal cord injury（SCI） by peripheral nerve graft combined with aFGF in rats.Method：One hundred and fifteen female Sprague-Dawley rats were randomly divided into four groups.Group A（n=30）：the spinal cord of rats was transected at T9 level,and 3mm of tissue was removed,the gap in the spinal cord was bridged by autogeneic intercostal nerve.Group B （n=30）：the same methods as group A,however,fibrin glue with aFGF was used to fix the autogeneic intercostal nerve.Group C （n=30）：transaction of the spinal cord at T9 level and removal of the tissue were made only.Group D （n=25）：laminectomy only.Somatosensory evoked potentials （SEP）,motor evoked potentials （MEP）, BDA anterograde tracing,FG retrograde tracing,BBB open field locomotor test were used to evaluate the restoration after SCI in rats.All the results were analyzed statistically using the SPSS 13.0 software package. Result： The mean of BBB scores of group A,B,C and D at 70 days after operation were 11.9±1.42,14.3± 1.27,0.6±0.51 and 21.0±0.00,among the groups,there was significant difference between every two groups （P〈 0.01）. 90 days after operation,the SEP waveform disappeared in the group C,latency and amplitude of SEP were （62.7±2.18）ms and （1.70±0.07）μV in the group A, （40.6±1.25 ）ms and （2.28±0.12）μV in the group B,（10.1±0.65）ms and （6.86±0.19）txV in the group D,among the group A,B and D,there was significant difference in the changes of SEP wave between every two groups （P〈0.01）.The MEP waveform disappeared in the group C,latency and amplitude of MEP were （12.7±0.50）ms and （1.0±0.18）mV in the group A, （9.2±0.20）ms and （1.3±0.13）mV in the group B,（6.4±0.32）ms and （2.0±0.18）mV in the group D,among the group A,B and D,the comparision beween every two groups shown significant difference （P〈0.01）.In the group A,BDA anterograde labeling of nerve fiber presented at the graft site and FG retrograde labeling of nerve cell in cervical cord dorsal horn,gracile nucleus,cuneate nucleus,reticular formation,ventral posterolateral nucleus and sensory cortex were found,the count of BDA and FG positive were 62.6±8.04 and 4086.9±182.58 in the group A,81.0±4,62 and 4979.3±489.43 in the group B,158.6±9.03 and 6 214.1±423.98 in the group D, BDA anterograde labeling of nerve fiber and FG retrograde labeling of nerve cell were not found in the group C,among the group A,B and D,the comparision between evry two groups had significant difference （P〈0.01）. Conclusion：The peripheral nerve transplantation can promote the SCI repair partly ,however,the transplantation with both peripheral nerve and aFGF can promote the SCI repair effectively.