大鼠坐骨神经切断后L_3～L_6脊髓前角运动神经元凋亡及C-Jun表达的研究

C-Jun expression and apoptosis in the spinal cord motoneurons after sciatic nerve transection in rat

目的 观察大鼠坐骨神经切断后L3 ～L6脊髓前角运动神经元的凋亡及C Jun表达。方法 在大鼠坐骨神经切断术后 12h、2 4h、3 6h、48h、3d、7d、9d、13d ,分别应用TUNEL及免疫组化技术检测神经元的凋亡和C Jun的表达。对照组动物接受同样的手术 ,但不切断神经 (假手术 )。结果 坐骨神经切断后 ,L3 ～L6脊髓前角运动神经元部分发生了凋亡 ,C Jun的表达呈双期性 ,在短暂、迅速的陡升期后接以平缓、持久的平台期。结论 研究结果提示外周神经切断后 ,部分神经元的死亡通过凋亡来介导 ,C Jun的早期表达与神经元的凋亡有关 ,而晚期则可能与神经再生相连。

Objective To investigate C Jun expression and apoptosis in the spinal cord motoneurons after unilateral sciatic nerve transection. Methods C Jun expression and apoptosis in the spinal cord motoneurons of L 3 ～ L 6 level were determined with immunohistochemistry and TUNEL method respectively at 12 hours, 24 hours, 36 hours, 48 hours, 3 days, 7 days, 9 days, and 13 days after sciatic nerve transection in rat. The control rats received same operations but without nerve transection (sham operation). Results Apoptosis was observed in some ipsilateral motoneurons of L 3 ～ L 6 spinal cord after sciatic nerve transection. While C Jun expression was biphasic, consisting of an early, transient, quick elevation phase and a secondary, smooth, more prolonged phase. Conclusions Injury induced death of neurons could be mediated by apoptosis. The early expression of C Jun is related to neuronal apoptosis and the later expression is perhaps involved in nerve regeneration.