神经肌接头阻滞差异性在术中面神经监测的应用基础研究

项目名称： 神经肌接头阻滞差异性在术中面神经监测的应用基础研究

项目编号： No.30872428

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 陈莲华

作者单位： 复旦大学

项目金额： 34万元

中文摘要： 术后面神经麻痹是耳科、颅底外科和头颈外科中涉及面神经的手术的重要并发症,如何合理使用肌松药，是涉及EEMG监测的手术麻醉的关键问题。我们的临床研究证明：面肌和四肢骨骼肌对肌松药的敏感性可能存在差异。 本项目利用大鼠面神经急性压榨伤模型，在离体实验水平，比较罗库溴铵对正常面神经、功能受损面神经支配的口轮匝肌和胫神经支配的腓肠肌的肌张力振幅的抑制程度，观察三种神经肌接头的突触前膜乙酰胆碱量子式释放数目、突触后膜乙酰胆碱受体数目与分布、肌纤维构成的差异。三组肌肉的肌张力振幅均随罗库溴铵浓度升高而呈剂量依赖性减小，口轮匝肌的MTAI%明显低于腓肠肌；正常及损伤侧口轮匝肌与腓肠肌终板区AChR密度依次递减，各浓度梯度下腓肠肌对罗库溴铵的饱和度均明显高于口轮匝肌；损伤面神经的EPP/MEPP降低较之于正常面神经明显。面神经支配的口轮匝肌对罗库溴铵的敏感性低于肢体神经支配的腓肠肌，其机制既与运动终板AChR受体密度及受体对罗库溴铵的亲和力有关又与突触前膜乙酰胆碱量子式释放有关；损伤面神经支配的口轮匝肌较之于正常面神经支配的口轮匝肌更容易受到罗库溴铵的抑制，机制主要与突触前膜乙酰胆碱量子式释放有关

中文关键词： 罗库溴铵；口轮匝肌；腓肠肌；乙酰胆碱；受体

英文摘要： Facial nerve paralysis is a common iatrogenic complication of surgeries involving the facial nerve, such as otology, skull base and head-neck surgeries. Evoked electromyography (EEMG) is commonly used for intraoperative monitoring of facial nerve to reduce the incidence of facial nerve injuries by identifying its location. Our clinical study indicated that different sensitivity may exist between facial-nerve-innervated muscles and somatic-nerve-innervated muscles.The current study was designed to investigate the differences in response to the non-depolarizing muscle relaxant rocuronium among orbicularis oris muscles innervated by normal or injured facial nerves and gastrocnemius muscle innervated by somatic nerve; to evaluate the presynaptic quantal release of acetylcholine and the number of acetylcholine receptors (AChR) on the end-plates, the affinity of AChR to rocuronium, as well as the fibre type composition of muscle fibers under a series of concentrations of rocuronium in rats, in vitro. A dose-dependent decrease in MTAs for the strips of normal or injured facial nerve innervated orbicularis oris and gastrocnemius muscles was detected after rocuronium incubation. ?At rocuronium concentrations of 2.5, 5, 7.5 and 10 μml, the MTAI% of the gastrocnemius muscle was significantly higher than that of orbicularis oris muscles (P<0.05).The density of AChR presented an incremental trend from the gastrocnemius to injured facial nerve innervated orbicularis oris and peaked in the normal facial nerve innervated orbicularis oris (P<0.05). As the concentration of rocuronium increased, the degree of saturation of AChR in the presence of the muscle relaxant rose in a dose-dependent manner in all three groups of muscles; within each concentration, the increase in the gastrocnemius group was significantly greater than that in the orbicularis oris group (P<0.05).The values of EPP/MEPP were dose-dependently decreased as the concentrations of rocuronium increased with the extent of decrease significantly larger in injured facial nerves than in normal facial nerves, and the largest in somatic nerves at rocuronium concentrations of 5, 7.5 and 10 μml (P<0.05). The sensitivity to rocuronium is lower in the facial-nerve-innervated orbicularis oris than those in somatic-nerve-innervated gastrocnemius, its mechanisms may be related to both the density of AChR at end-plates as well as the affinity of AChR to rocuronium and the presynaptic quantal release of acetylcholine; The more easily inhibition by rocuronium on the injured facial-nerve-innervated orbicularis oris compared to normal facial-nerve-innervated orbicularis oris is related mainly to the presynaptic quantal release of acetylcholine.

英文关键词： rocuronium; orbicularis oris; gastrocnemius; acetylcholine; receptors