神经根撕脱后脊髓运动神经元的病理表现  

Pathologic changes of spinal motoneurons function and morphology after root avulsion

作　　者：周丽华[1] 袁群芳[1] 李方澜[1] 韩曙[1] 姚志彬[1] 

机构地区：[1]中山大学中山医学院解剖学教研室,广东广州510080

出　　处：《中国病理生理杂志》2002年第4期392-394,共3页Chinese Journal of Pathophysiology

摘　　要：目的 :观察神经根撕脱后脊髓前角运动神经元的病理表现 ,探讨在该条件下运动神经元死亡的神经生物学机制。方法 :选择成年SD雌性大鼠 2 0只 ,体重 2 0 0 - 30 0g ,撕脱右侧臂丛C5-T8神经根 ,术后动物存活 3d、5d、1周后取C5-C8节段脊髓 ,对冰冻切片行NADPH -d组化、c -jun免疫组化、中性红和HE染色。观察神经元的形态 ,计数脊髓前角NOS阳性运动神经元及存活运动神经元数目 ,以非损伤侧的前角运动神经元数目为 10 0 % ,计算百分比。结果 :神经根撕脱 3d、5d、1周后 ,损伤侧脊髓前角NOS运动神经元平均阳性率分别为 :0 74%± 0 5 9%、2 4 83%± 6 73%、5 1 16 %± 8 6 7%。神经元平均存活率分别为 93 0 0 %± 4 32 %、93 6 7%± 5 2 7%、89 83%±2 6 5 % ;c -Jun从撕脱术后 3d就有表达 ,5d后表达开始减少。运动神经元形态变化不明显。 1周时偶见前角运动神经元的胞核偏位 ,但核膜清晰 ,核仁尚存 ,染色体固缩。结论 :脊神经根撕脱 1周内 ,脊髓前角运动神经元NOS表达递增 ,c-Jun表达递减 ,运动神经元开始死亡。NO/NOS可能通过抑制神经元损伤后的再生反应 ,促进脊髓前角运动神经元的死亡。AIM: To investigate the pathological changes of motoneuron's function and morphology after root avulsion in order to study the neurobiology mechanism of motoneuron death. METHODS: Twenty female adult Sprague-Dawley rats, 200-300 g were used. The C 5-C 8, T 1 roots of the right brachial plexus were avulsed. All rats were killed 3 d, 5 d or 1 week after avulsion. One group of the C 5-C 8 spinal cords freeze sections (40 μm thick) were collected for the NADPH-d histochemistry with neural red counterstained. Another group of the C 5-C 8 spinal cords freeze sections (40 μm thick) were collected for the c-Jun immunocytochemistry stain. The paraffin sections (5 μm thick) were collected for HE stain. The amount of NOS-positive and survival motoneurons was counted. The percentage of NOS expression and motoneuron survive were quantitatively analyzed considering the amount of contra lateral motoneurons as one hundred percent. RESULTS: The NOS expression rate was 0.74%±0.59% (3 d), 24.84%±6.73%(5 d), or 51.16%±8.67% (1 week), respectively. The survive rate was 93.00%±4.32% (3 d), 93.67%±5.27% (5 d), or 89.83%±2.65% (1 week), respectively. The motoneuron expressed c-Jun as early as 3 days after avulsion. The expression declined afterward until one week after avulsion. There was no significant change on the size of motoneuron. The nuclear membrane was still clear but some nuclei were not located in the middle of the cell body. There were some nucleoli with the chromatin condensation. CONCLUSION: The motoneuron NOS expression and cell death were increased within one week after spinal root avulsion. meanwhile, the c-jun expression was decreased. The NO/NOS may induce the motoneuron death by inhibiting the regenerating reactions of motoneuron after root avulsion injury.

关 键 词：脊神经根 前角细胞 尼克酰胺腺嘌呤二核苷酸黄递酶 运动神经元 病理 神经根撕脱 动物实验 

分 类 号：R744.802[医药卫生—神经病学与精神病学]