家兔腓肠肌亚部神经切断对其肌内神经、运动终板和肌梭的影响

Effect of denervation on intramuscular nerve, motor end plate and muscle spindle of the compartment of lateral gastrocnemius in rabbit

目的 切断家兔腓肠肌外侧头肌亚部神经后 ,观察肌内神经、肌梭、运动终板带、肌湿重等的形态学变化。方法 4 0只家兔随机分成对照组和神经切断组。用Sihler s肌内神经染色法染肌内神经 ;用乙酰胆碱脂酶整肌染色法染肌运动终板 ;用HE染色法染肌梭。结果 (1)术后 2周亚部肌湿重明显下降 (P <0 0 5 ) ,肌运动终板带模糊不清 ,肌内神经染色变浅 ,三级分支消失 ,但肌梭形态及梭内肌纤维尚无明显改变 ;(2 )术后 4周肌湿重进一步下降 (P <0 0 1) ,运动终板带完全消失 ,肌内二级分支染色无 ,肌梭形态及数量有改变 ;(3)术后 12周肌肉明显萎缩 ,发生纤维化 ,运动终板带无 ,肌内神经染色无 ,仅留有鞘管样结构 ,未见神经再生 ,肌梭形态、数量明显改变 ;(4)术后 16周各参数与 12周相比差异无显著性。邻近正常肌未见有侧支神经支配失神经的亚部。结论 (1)家兔腓肠肌外侧头各亚部在神经切断术后 4周 ,运动终板、肌梭的数量和形态有改变 ;(2 ) 12周后肌内神经染色仅有神经外膜鞘管样结构残存 ;(3)术后 16周末见原位的神经再生和相邻亚部神经侧支的再支配。

Objective To investigate the morphology change of intramuscular nerve, motorend plate (MEP) following denervation, muscle spindle and muscle wet weigh biz cuttingdifferent nerve in compartment levels of lateral gastrocnemius in rabbit. Methods (1)Sihler's intramuscular neural staining technique was used to observe the change of intramuscular nerve at different periods of post-operation. (2)AChE straining technique with integrated muscle was used to investigate the change of MEP band in different rabbit models. (3)HE staining technique was used to study the change of muscle spindle in morphology. Results (1)Two weeks later, muscles withered significantly (wet weight, P<0.01); MEP band became vague; the color of secondary nerve branches became faint in muscle; muscle spindles changed weeks later, muscle wet weight was reduced further (P<0.01); MEP band little. (2)Fourd was appeared, the secondary nerve branches can't be seen in muscle; the number of muscle spindles was decreased. (3)Twelve weeks later, muscles withered seriously; fibrosis of muscle sappeared; the MEP band disappeared completely; Nothing but nerve membrane-tubes could beseen in muscle; regenerated nerve could not be found in muscle; the number of muscle spindlesdecreased significantly; irregular muscle spindles appeared. (4)Sixteen weeks later, these data were not changed significantly. The nerve branches of the normal department couldn't arrive at the injuried department. Conclusions In experimental group: (1)Four weeks later, the number and morphology of MEP and muscle spindle were changed. (2)Twelve weeks later,muscles and intramuscular nerve degenerated so that nerve could be seen in injuried department but nerve membrane-tubes. (3)None of regenerating nerve from situ or neighbour compartment could be observed after sixteen weeks later.