转化生长因子-β在颌面部爆炸伤后面神经中的表达

Expression of transforming growth factor Beta in facial nerve following maxillofacial blast injury

目的 :观察颌面部爆炸伤后兔面神经中转化神经生长因子β(TGF β)蛋白表达的变化 ,了解TGF β在爆炸伤后面神经损伤修复过程中所起的作用 .方法 :选用 0 .12 5 gTNT当量的点状爆炸源距新西兰大白兔左面部 2mm引爆致伤 ,于伤后 6h ,1,3,7,15 ,2 1d取面神经分别进行组织学、免疫组织化学观察 .结果 :伤后 6h ,神经纤维部分断裂 ,神经外膜连续 .伤后 1d ,神经纤维广泛损伤 ,神经外膜仍连续 ,炎细胞浸润 .伤后 3d出现髓鞘空泡样变 ,板层分离 ,轴索发生广泛肿胀、断裂 .7d后轴索染色不均 ,坏死崩解 ,炎症开始消退 .15d时未见明显轴索再生 .伤后 3d时神经伤处TGF β抗原呈阳性反应 ,7d时损伤处的雪旺细胞明显增多 ,TGF β抗原呈强阳性反应 ,为表达高峰 ,之后TGF β表达的量有所下降 ,雪旺细胞数量无明显降低 .结论 :TGF β参与爆炸伤后面神经损伤的病理过程 ,TGF β主要在髓鞘中表达 ,与雪旺细胞数量的变化存在相关性 ,并与神经损伤的组织学变化有时间相关性 .

AIM: To study the changes of transforming growth factor beta (TGF β) expression in rabbit facial nerve suffering maxillofacial blast injury. METHODS: Exploding 0.125 g TNT quantum dynamite balls 2 mm away from rabbit's left face simulated the impact wave. After 6 h, 1, 3, 7, 15, 21 d, we observed the rabbits' facial nerves to study histopathological changes and performed immunohistochemistry examination at various time. RESULTS: 6h later, facial nerve fibers appeared injured partly while the nerve is still continuous. One day later, the facial nerve was found to be broken widely, but the neurilemma is still continuous. Inflammatory cells appear in the area of nerve injury. After 3 days, nerve fibers swelled and broke off. One week later, the inflammation began to scatter. The TGF β antibody was positive 3 days later, and reached the tip after 7 days while Schwann cells increased greatly. And then the TGF β expression decreased gradually. CONCLUSION: TGF β plays an important role in the pathologic process of facial nerve blast injury. TGF β mainly express in myelin and correlate to the proliferation of Schwann cells and nerve injury changes.