【作者】 程勇泉；

【导师】 高志强；

【作者基本信息】 中国协和医科大学 ， 临床医学， 2008， 博士

【摘要】 目的1.探索可简单准确地调控面神经雪旺细胞(Schwann Cells,SC)活性的方法。2.观察不同活性的SC对面神经在SD大鼠中行同种异体原位移植中神经再生的效果的影响。方法1.定量测定冻融法对面神经SC活性的影响,将动物分为新鲜神经组(F组)、冻融一次组(FTI组)和冻融五次组(FTV组)。2.每组3条面神经用钙黄绿素-AM(Calcein-AM)染色,以共聚焦显微镜测定荧光强度,反映SC活性。每组9只大鼠接受单侧同种异体面神经移植。3.术后2、4、8周各取3只大鼠的面神经移植物中段行髓鞘锇酸染色,观察轴突再生情况,计数新生轴突。术后第8周测定大鼠手术侧和对侧面神经的动作电位幅度及神经传导速度。结果1.平均荧光强度:F组为140.93±17.55/μm~2,FTI组56.99±7.10/μm~2,FTV组28.46±4.11/μm~2。2.术后第8周F组、FTI组和FTV组中段的轴突计数分别为356.60±75.57、334.41±93.71和301.60±95.67,无统计学差异。三组的动作电位振幅和神经传导速度也无统计学差异。3.术后第8周,FTI组神经新生轴突分布较FTV组和F组更为均匀,髓鞘厚度和轴突横截面积更大,髓鞘更为成熟。结论1.快速冻融法可以有效和准确地调控面神经SC的活性,冻融一次可以将神经SC活性降低到新鲜面神经的40%,而反复冻融五次可降低到20%。2.在本实验条件下,不同雪旺细胞活性对大鼠同种异体面神经移植的再生轴突数目和神经电生理功能没有明显影响。但术后第8周,FTI组的新生髓鞘在形态学上优于FTV组和F组,提示雪旺细胞活性降低到一定范围内可能有利于面神经再生。更多还原

【Abstract】 Objectives1.To explore a simple and precise method to modulate the viability of Schwann cell (SC) in Facial Nerve.2.Facial nerves with different SCs’ viability are allotransplanted in SD rats and observe nerve regeneration to evaluate the effects of SCs’ viability on nerve transplantation.Methods1.The effects of freeze-thaw method on SCs’ viability of Facial Nerve were measured. SD rats were assigned to flesh nerve group(Group F),freeze-thaw-one -time group (Group FTI) and freeze-thaw-five -time group(Group FTV).2.Three nerves in each group were stained with Calcein-AM,and fluorescent strengths were measured by confocal microscope to reflect the viability of SC.Nine SD rats in each group were received unilateral facial nerve allotransplantation.3.The middle grafts of 3 rats in each group were stained with osmic acid to observe the regeneration of axons and were counted regenerated axons in 2,4 and 8 weeks after transplantation.The amplitude of action potential and neural conducting velocity (NCV) of transplanted facial nerve and contralateral facial nerve were measured in 8 weeks after transplantation.Results1.The mean fluorescent strength of Group F was 140.93±17.55/μm~2,that of Group FTI was 56.99±7.10/μm~2,and Group FTV 28.46±4.11/μm~2.2.The axons counts of Group F,Group FTI and Group FTV in Week 8 after transplantation were356.60±75.57,334.41±93.71 and 301.60±95.67 respectively,the difference was not statistically significant.There was also no significant statistical difference in the amplitude of action potential and NCV of three groups.3.The distribution of regenerative axons of Group FTI in Week 8 after transplantation was more even than that of Group FTV and Group F,and the thickness of myelin and transactional area of axons were larger,myelin was more mature.Conclusion1.The viability of SC can be effectively and precisely modulated by fast freeze-thaw method,it can be decreased to 40%of fresh nerve by freeze-thaw for one time,while 20%by freeze-thaw for 5 times.2.Under conditions of this experiment,no significant statistical differences were found about effects of Schwann cells’ viability on regeneration of facial nerve allotransplantation.But the morphology of regenerated axons in Group FTI was better than that of Group FTV and Group F.It is suggested that lower viability of SC in certain range may be beneficial for regeneration of facial nerve.更多还原