NEURAL CELL-ADHESION MOLECULE (N-CAM) ACCUMULATES IN DENERVATED AND PARALYZED SKELETAL-MUSCLES
NEURAL CELL-ADHESION MOLECULE (N-CAM) ACCUMULATES IN DENERVATED AND PARALYZED SKELETAL-MUSCLES
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DOI：
10.1073/pnas.82.13.4544
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发表时间：
1985-01-01
影响因子：
11.1
通讯作者：
SANES, JR
中科院分区：
文献类型：
--
作者：
COVAULT, J;SANES, JR
用免疫荧光和免疫印迹方法研究了神经细胞黏附分子(N-CAM)在大鼠骨骼肌中的数量和分布，该分子被认为是介导神经元与培养的肌管黏附的分子。N-CAM存在于胚胎肌管的表面，但随着发育的进行，它会消失，在成年肌肉中几乎不存在。成年肌肉失神经后，N-CAM重现。在失神经肌肉中，N-CAM既与肌肉纤维有关，也与纤维间隙中的细胞有关。间隙中的N-CAM集中在失神经终板附近，这些终板是神经再支配的优势部位。已知的神经肌肉麻痹在许多方面类似于去神经支配，也会导致N-CAM的积累。再生的轴突在终末带有N-CAM，再神经支配会导致N-CAM从肌肉中消失。去神经支配会导致N-CAM在小鼠和鸡以及大鼠肌肉中的积聚。N-CAM在肌肉中的表达受肌肉“S”神经支配状态的调节，由于N-CAM丰富的肌肉(胚胎、失神经支配和瘫痪的肌肉)能够接受突触，而N-CAM缺乏的肌肉(正常成人和重新神经支配的肌肉)不能接受超神经支配，N-CAM可能反过来参与调节肌肉的S对神经支配的敏感性。
Immunofluorescence and immunoblotting methods were used to study the amount and distribution of the neural cell adhesion molecule (N-CAM) in rat skeletal muscle; this molecule is thought to mediate adhesion of neurons to cultured myotubes. N-CAM is present on the surface of embryonic myotubes, but it is lost as development proceeds and is nearly absent from adult muscle. Denervation of adult muscle results in the reappearance of N-CAM. In denervated muscle, N-CAM is associated both with muscle fibers and with cells in interstitial spaces between fibers. The N-CAM in interstitial spaces is concentrated near denervated endplates, which are known to be preferential sites for reinnervation. Paralysis of innervated muscle, known to mimic denervation in many respects, also induces the accumulation of N-CAM. Axons that regenerate to reinnervate muscle bear N-CAM on their terminals, and reinnervation results in the disappearance of N-CAM from muscle. Denervation induces accumulation of N-CAM in mouse and chicken, as well as in rat muscles. The expression of N-CAM in muscle is regulated by the muscle''s state of innervation. In that N-CAM-rich muscles (embryonic, denervated and paralyzed) are known to be competent to accept synapses while N-CAM-poor muscles (normal adult and reinnervated) are refractory to hyperinnervation, N-CAM might, in turn, participate in regulating muscle''s susceptibility to innervation.