Engel A G, Lindstrom J M, Lambert E H, Lennon V A
Neurology. 1977 Apr;27(4):307-15. doi: 10.1212/wnl.27.4.307.
Peroxidase-conjugated alpha-bungarotoxin (P-BGT) was used for the ultrastructural localization of the acetylcholine receptor in end-plates in external intercostal muscles of four patients with myasthenia gravis, in forelimb digit extensor muscles of rats with advanced chronic experimental autoimmune myasthenia gravis, and in suitable human and rat controls. In control end-plates, the previously reported localization of acetylcholine receptor on the terminal expansions of the postsynaptic folds and, in traces, on the presynaptic membrane was confirmed. By contrast, in myasthenia gravis some postsynaptic regions bound no P-BGT; in other regions, the folds displayed only faint traces of the reaction product, or only some segments of the postsynaptic membrane showed the reaction product; finally, in some regions there was no apparent decrease in reaction product. In general, those postsynaptic regions showing the greatest decrease in P-BGT binding were also the simplest or showed the most degenerative changes, and the presynaptic staining was decreased in proportion to the decrease in the adjacent postsynaptic P-BGT binding. In the experimental animals, the abnormalities in the amount and distribution of the acetylcholine receptor were essentially like those in the more severely affected patients. Morphometric estimates of the postsynaptic acetylcholine receptor surface correlated well with the patients' clinical status and linearly with the miniature end-plate potential amplitude.
过氧化物酶结合的α-银环蛇毒素（P-BGT）用于对4例重症肌无力患者肋间外肌终板、晚期慢性实验性自身免疫性重症肌无力大鼠前肢指伸肌以及合适的人类和大鼠对照的乙酰胆碱受体进行超微结构定位。在对照终板中，证实了先前报道的乙酰胆碱受体位于突触后褶皱的终末膨大上，以及少量位于突触前膜上。相比之下，在重症肌无力中，一些突触后区域不结合P-BGT；在其他区域，褶皱仅显示出微弱的反应产物痕迹，或者只有突触后膜的某些节段显示出反应产物；最后，在一些区域，反应产物没有明显减少。一般来说，那些显示P-BGT结合减少最明显的突触后区域也是最简单的或显示出最退化性变化的区域，并且突触前染色随着相邻突触后P-BGT结合的减少而按比例减少。在实验动物中，乙酰胆碱受体数量和分布的异常与病情较重的患者基本相似。突触后乙酰胆碱受体表面的形态计量估计与患者的临床状态密切相关，并与微小终板电位幅度呈线性相关。
