失神经支配肌肉提取液对创伤性运动神经元胞体死亡的保护作用  

RESCUE OF AXOTOMY-INDUCED MOTONEURONAL CELL DEATH BY DENERVATED SKELETAL MUSCLE EXTRACTS──AN IN VIVO STUDY IN NEONATAL RATS

作　　者：孔吉明[1] 钟世镇[1] 胡耀民[1] 李忠华[1] 

机构地区：[1]第一军医大学解剖学教研室

出　　处：《神经解剖学杂志》1994年第4期279-283,共5页Chinese Journal of Neuroanatomy

基　　金：国家自然科学基金

摘　　要：周围神经损伤后的功能恢复常不尽如人意，原因之一是周围神经损伤会导致一定数量的神经元胞体死亡。对于感觉神经元胞体的退变死亡，于损伤局部连续施用神经生长因子即可取得较好的保护效应，但对于运动神经元胞体的损伤性死亡，目前尚无一种有效的保护因子。作者从失神经支配肌肉能诱导其邻近的正常运动神经纤维发芽生长这一现象受到启发，研究了失神经支配肌肉提取液（ＤＭＥ）对周围神经损伤所导致的运动神经无胞体死亡的保护作用。结果表明，用失去神经支配后５ｄ的骨骼肌制成的提取液最具运动神经元营养活性。经乳鼠坐骨神经损伤实验模型检测，这种自制的ＤＭＥ能保护８７．６％的脊髓腰段前角运动神经元在坐骨神经损伤后一个月继续存活，而正常骨骼肌提取液的保护率仅为３７．３％。如不加以保护，则神经元胞体的存活率仅为８％。本研究结果提示骨骼肌的失神经支配可能会引起肌肉的某些代谢的改变，从而合成和分泌一些靶源性运动神经营养因子。Functional restoration of a peripheral nerve following axotomy is unsatisfactory and axotomy-induced neuronal cell death is believed to be one of the main reasons. There has ben considerable evidence demonstrating that nerve growth factor (NGF) could, both in vitro and in vivo, protect the dorsal root ganglion neurons and sympathetic neurons from axotomy-induced cell death. Unfortunatdy it is less effective in protecting motoneurons, and there is no single ideal substance so far that could be used in vivo for the protection of traumatic motoneuronal degeneration, A variety of studies showed that approximately four days after a muscle is partially denervated, the remaining motor axons produced both terminal and collateral sprouts, suggesting that the inactive skeletal muscle may release a diffusible factor that is neurotrophic.Our previous study demonstrated that denervated skeletal muscle bridge was able to promote peripheral nerve regeneration and growth. In the present study, denervated skeletal muscle extracts (DME) were prepared from adult Wistar rats and their protective effects on motoneuronal survival were tested in neonatal Wistar rats three days of age, The results show that a DME prepared from 5-day-denervated muscle is most neurotrophic.Determined by neurorial cell counts up to one month following sciatic resection, 87.6% of the corresponding motoneurons were proterted by the DME from cell death, while only 37.3% survived when treated with normai skeietal muscle extract. In control group treated with saline,the survival rate of motoneurons after nerve section was 9.1 %. All these add up to a concept that denervared skeletal muscle may secrete a neurotrophic factor which is specific to motoneurons.

关 键 词：周围神经损伤 运动神经元 死亡 DME 保护 

分 类 号：R651.302[医药卫生—外科学] R602[医药卫生—临床医学]