高压氧前处理脊髓损伤大鼠前角运动神经元的凋亡*☆

背景：脊髓损伤后难以修复，损伤后保护残存的神经元是促进神经再生的关键。 目的：验证高压氧预处理可以通过抑制早期的细胞凋亡来保护脊髓前角运动神经元。 方法：随机将26只雄性Wistar大鼠等分成模型组和实验组。实验组在给予高压氧5 d后与模型组同时制作脊髓T9~10全横断模型。 结果与结论：尼氏染色显示脊髓T9~T10全横断后8 h及1 d，脊髓前角的浓染的细胞多见，与模型组相比，实验组脊髓前角浓染的细胞较少。TUNEL染色也显示脊髓T9~T10全横断后脊髓损伤后8 h~1 d，2组大鼠脊髓前角内均可见大量的凋亡神经元，3 d时凋亡神经元数量减少。相比于模型组，高压氧预处理8 h，1 d后大鼠脊髓前角凋亡神经元较少(P < 0.05，        P < 0.01)。说明高压氧预处理能对脊髓损伤后前角运动神经元起保护作用。  

Apoptosis of anterior horn motor neurons after hyperbaric oxygen preconditioning in spinal cord injury rats

BACKGROUND: Spinal cord injury is difficult to repair. The protection of relict neurons is the key for promoting neural regeneration. OBJECTIVE: To test whether spinal cord anterior horn motor neurons are protected by hyperbaric oxygen preconditioning through inhibition of early apoptosis. METHODS: A total of 26 Wistar male rats were randomly divided into two groups: control group and hyperbaric oxygen group. Rats in hyperbaric oxygen group were administrated with hyperbaric oxygen for 5 days. Complete spinal cord (T9-T10) transection model was constructed on the 5th day after hyperbaric oxygen. In the meantime, complete spinal cord (T9-T10) transection model was constructed for control rats. RESULTS AND CONCLUSION: Nissl staining demonstrated that hyperchromic cells were common in the two groups at 8 hour and 1 day after spinal cord transection at T9–T10. The number of hyperchromic cells in the hyperbaric oxygen group was less than that in the control group. TUNEL staining demonstrated that the massive apoptotic neurons were found at 8 hour and 1 day after the spinal cord transection at T9–T10 in rat anterior horn of spinal cord in both groups; the number of apoptotic neurons decreased on the 3rd day. The number of apoptotic spinal cord anterior horn motor neurons in the hyperbaric oxygen group was smaller than that in the control group at 8 hour and 1 day after hyperbaric oxygen (P < 0.05,   P < 0.01). These findings indicate that hyperbaric oxygen preconditioning has a protective effect on anterior horn motor neurons after spinal cord injury.