NERVE-INDUCED AND SPONTANEOUS REDISTRIBUTION OF ACETYLCHOLINE RECEPTORS ON CULTURED MUSCLE-CELLS
NERVE-INDUCED AND SPONTANEOUS REDISTRIBUTION OF ACETYLCHOLINE RECEPTORS ON CULTURED MUSCLE-CELLS
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DOI：
10.1113/jphysiol.1977.sp011880
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发表时间：
1977-01-01
影响因子：
5.5
通讯作者：
COHEN, MW
中科院分区：
文献类型：
--
作者：
ANDERSON, MJ;COHEN, MW
从非洲爪蟾胚胎获得的肌节肌肉的三天龄培养物用α-将银环蛇毒素与天然毒素混合，以确保随后插入肌膜的ACh [乙酰胆碱]受体不被染色。然后将神经管细胞加入培养物中。当1-3天后检查培养物时，荧光染色与神经-肌肉接触部位相关。在某些情况下，染色沿着接触路径延伸的距离比在非接触肌细胞上看到的染色斑更长。通过在一天的时间内对同一肌肉细胞进行连续观察，证实了神经-肌肉接触部位新荧光染色区域的发展。在没有神经接触的肌肉细胞上进行的类似实验显示，通常在细胞生长的区域形成了新的受体补丁。非接触肌细胞上的大多数荧光斑在1-2天的过程中没有发生大小或形状的变化。观察到一些扩大、收缩和消失的例子。乙酰胆碱受体聚集在肌膜内，自发和响应神经支配。在后一种情况下，连接外受体聚集在神经接触部位，从而促进神经下肌膜中高受体密度的发展。这种受体重新分布的过程发生在缺乏突触或收缩活动的情况下。乙酰胆碱受体的重新分配中可能涉及的机制进行了讨论，在那些似乎调节配体诱导的凝集素和免疫球蛋白受体的分布的变化。
Three day old cultures of myotomal muscle, obtained from embryos of Xenopus laevis, were stained with fluorescent conjugates of .alpha.-bungarotoxin and maintained in native toxin in order to ensure that ACh [acetylcholine] receptors subsequently inserted into the sarcolemma were not stained. Neural tube cells were then added to the cultures. When cultures were examined 1-3 days later, fluorescent stain was associated with sites of nerve-muscle contact. In some cases the stain along the path of contact extended for greater distances than the patches of stain seen on non-contacted muscle cells. The development of new areas of fluorescent stain at sites of nerve-muscle contact was confirmed by making successive observations on the same muscle cell over a period of a day. Similar experiments on muscle cells not contacted by nerve revealed the formation of new receptor patches, usually in areas of cell growth. The majority of fluorescent patches on non-contacted muscle cells did not undergo changes in size or shape over the course of 1-2 days. Some examples of enlargement, shrinkage and disappearance were observed. ACh receptors aggregated within the sarcolemma, spontaneously and in response to innervation. In the latter case extrajunctional receptors accumulated at the site of nerve contact thereby contributing to the development of high receptor density in the subneural muscle membrane. This process of receptor redistribution occurred in the absence of synaptic or contractile activity. Possible mechanisms involved in the redistribution of ACh receptors are discussed in relation to those which appear to modulate ligand-induced changes in the distribution of lectin and immunoglobulin receptors.