目的探讨面神经局部缺血对面神经及面神经核的影响,为临床腮腺切除术提供参考。方法选用家兔,采用同体对照的方法,模拟人腮腺切除手术。实验侧于手术显微镜下,游离面神经并破坏其外血管系,切除腮腺。术后家兔存活4周,观察以下指标:分别检测家兔实验侧和对照侧面神经颊支的传导速度、CMAP波幅和潜伏期;取双侧茎乳孔外面神经干,透射电镜下观察面神经超微结构的变化;取双侧面神经核,Western Blotting法检测面神经核乙酰胆碱转移酶(CHAT)表达的变化,PCR-ELISA法观察面神经核端粒酶活性的变化。结果实验侧面神经颊支的传导速度明显低于对照侧、潜伏期明显长于对照侧、波幅明显低于对照侧(P<0.01,P<0.05)。实验侧面神经超微结构发生明显变化,以轴索变性为主,包括轴索内微丝增生、断裂,线粒体肿胀、嵴断裂,变性轴索溶解等。实验侧面神经核CHAT的表达和端粒酶活性明显低于对照侧(P<0.01,P<0.05)。结论游离面神经破坏其外血管系切除腮腺,可导致面神经超微结构发生明显改变、面神经传导功能下降,进而导致面神经核神经元合成乙酰胆碱的含量下降、神经元凋亡增加;提示临床腮腺切除时,应尽可能保护面神经外血管系,以减少面瘫的发生。 Objective To investigate the effects of facial nerve ischemia on the facial nerve and facial nerve nuclei and to provide a reference for clinical parotidectomy. Methods Rabbits were selected, using the method of homologous control to simulate parotid gland resection. Experimental side of the operating microscope, free facial nerve damage and destruction of the external vascular system, removal of the parotid gland. Rabbits survived for 4 weeks. The following indexes were observed: The conduction velocity, CMAP amplitude and latency of lateral buccal branch of the experimental and control rabbits were measured respectively. The outer trunk of the bilateral styloid ducts was observed by transmission electron microscopy. The changes of the expression of acetylcholinesterase (CHAT) in the facial nucleus were detected by Western Blotting. The changes of telomerase activity in the facial nucleus were observed by PCR-ELISA. Results The conduction velocity of lateral buccal branches in experimental group was significantly lower than that in control group (P <0.01, P <0.05). The latency was significantly longer than that in control side. The ultrastructural changes of the lateral facial nerve were observed and the axonal degeneration was predominant, including the proliferation, fracture, mitochondria swelling, cristae fractures and axonal dissolution in the axon. The expression of CHAT and telomerase activity in the lateral nucleus of the experimental group were significantly lower than those in the control group (P <0.01, P <0.05). Conclusions Free facial nerve can destroy the parotid gland in the external vasculature, leading to obvious changes in the ultrastructure of the facial nerve and decreased facial nerve conduction function, leading to decreased levels of acetylcholine synthesis and neuronal apoptosis in the facial nerve nucleus. It suggests that in clinical parotid gland resection, As far as possible to protect the facial nerve blood vessels, in order to reduce the incidence of facial paralysis.