Franco-Obregón A, Lansman J B
Department of Pharmacology, School of Medicine, University of California, San Francisco 94143-0450, USA.
J Neurosci Res. 1995 Nov 1;42(4):452-8. doi: 10.1002/jnr.490420403.
Single-channel activity was recorded from cell-attached patches on skeletal muscle cells isolated from wild-type mice and from mice carrying the dy or mdx mutations. Spontaneous openings of the nicotinic acetylcholine receptor channel (nAChR) were detected in virtually all recordings from either dy/dy or dy/+ myotubes, but only infrequently from wild-type or mdx myotubes. Spontaneous openings were also present in most recordings from undifferentiated myoblasts from all of the mouse strains studied. The biophysical properties of the spontaneous activity were similar to those of the embryonic form of the nAChR in the presence of acetylcholine (ACh). Examination of the single-channel currents evoked by low concentrations of ACh showed a reduced sensitivity to the agonist in the dystrophic dy and mdx myotubes, but not in wild-type myotubes. The results suggest that alterations in nAChR function are associated with the pathogenesis of muscular dystrophy in the dy mouse.
从野生型小鼠以及携带dy或mdx突变的小鼠分离出的骨骼肌细胞的膜片钳记录单通道活性。在几乎所有来自dy/dy或dy/+肌管的记录中都检测到烟碱型乙酰胆碱受体通道（nAChR）的自发开放，但在野生型或mdx肌管的记录中很少见。在所研究的所有小鼠品系的未分化成肌细胞的大多数记录中也存在自发开放。自发活性的生物物理特性与在乙酰胆碱（ACh）存在下nAChR胚胎形式的特性相似。低浓度ACh诱发的单通道电流检查显示，营养不良的dy和mdx肌管中对激动剂的敏感性降低，但野生型肌管中未降低。结果表明，nAChR功能改变与dy小鼠的肌肉营养不良发病机制有关。
