Eldefrawi M E
Fed Proc. 1978 Dec;37(14):2823-7.
Rabbits immunized with acetylcholine (ACh) receptor purified from Torpedo electroplax were studied after they were paralyzed and exhibiting respiratory distress. Intercostal muscles from the immunized rabbits had reduced amplitude of miniature end-plate potentials (MEPPs) as well as reduced junctional ACh sensitivity. However, a large percentage of the cells studied (40%), which exhibited no MEPPs, had junctional ACh sensitivity that was 45% of normal. It is suggested that, unlike myasthenic patients, such paralyzed and dying rabbits may have, in addition to postsynaptic damage, neurons that are damaged or separated from the muscle. Serums from six paralyzed rabbits inhibited binding of [3H]ACh and [125I]alpha-bungarotoxin to Torpedo ACh-receptor to varying degrees: 18.8--95.5% and 42.5--86.1%, respectively. Immune serums also inhibited the carbamylcholine-induced 22Na efflux from Torpedo microsacs, but neither they nor the immunoglobulins inhibited neuromuscular transmission when applied to intercostal muscles from a control rabbit. The data suggest that homology between receptor and antibody is important for inhibition of ACh binding to its receptor and its function. The role of complement in pathogenesis is also discussed, and so is the relationship of the ACh-receptor to its ionic channel.
用从电鳐电板纯化的乙酰胆碱（ACh）受体免疫的兔子在出现瘫痪并表现出呼吸窘迫后接受了研究。免疫兔子的肋间肌微小终板电位（MEPPs）幅度降低，同时接头处ACh敏感性降低。然而，所研究的细胞中有很大比例（40%）未表现出MEPPs，但其接头处ACh敏感性为正常的45%。有人提出，与重症肌无力患者不同，这类瘫痪濒死的兔子除了有突触后损伤外，可能还有受损或与肌肉分离的神经元。六只瘫痪兔子的血清对[3H]ACh和[125I]α-银环蛇毒素与电鳐ACh受体的结合有不同程度的抑制：分别为18.8% - 95.5%和42.5% - 86.1%。免疫血清也抑制了氨甲酰胆碱诱导的电鳐微囊22Na外流，但当将它们或免疫球蛋白应用于对照兔子的肋间肌时，它们均未抑制神经肌肉传递。数据表明，受体与抗体之间的同源性对于抑制ACh与其受体的结合及其功能很重要。还讨论了补体在发病机制中的作用以及ACh受体与其离子通道的关系。
