Action of Lambert‐Eaton myasthenic syndrome IgG at mouse motor nerve terminals
Action of Lambert‐Eaton myasthenic syndrome IgG at mouse motor nerve terminals
复制标题
兰伯特-伊顿肌无力综合征 IgG 对小鼠运动神经末梢的作用
作者：
C. Prior;B. Lang;D. Wray;J. Newsom
我们利用小鼠被动转移模型研究了从4例Lambert - Eaton肌无力综合征（LEMS）患者（其中2例伴有小细胞癌）中提取的IgG的电生理作用。小鼠给予LEMS或对照IgG或血浆，每日10 ~ 60 mg。细胞内微电极记录来自横膈肌。LEMS IgG和血浆同样降低终板电位量子含量，证实IgG是活性因子。LEMS IgG对C5‐缺陷小鼠同样有效，表明不需要晚期补体成分。定量含量下降和恢复的时间过程与小鼠血清中人IgG含量下降和恢复的时间过程密切相关，每例达到一半效果的时间约为1.5天。IgG的结合/解离或抗原决定因子（可能是Ca2+通道）的下调/上调，其半衰期在2至36小时之间。结果证实了我们的概念，即神经末梢决定因子IgG抗体是LEMS中递质释放紊乱的基础。
We have studied the electrophsiological effects of IgG obtained from four patients with Lambert‐Eaton myasthenic syndrome (LEMS) (two with small cell carcinoma), using the mouse passive transfer model. Mice received LEMS or control IgG or plasma, 10 to 60 mg daily. Microeletrode intracellular recordings were from diaphragm muscle. LEMS IgG and plasma decreased end‐plate potential quantal content similarly, confirming IgG as the active factor. LEMS IgG was equally effective C5‐deficient mice, indicating that late complement components are not required. The time course of decline and recovery of quantal content closely followed that of the human IgG in the mouse serum, with time to half‐maximal effect of about 1.5 days in each case. Binding/dissociation of IgG or down/up regulation of the antigenic determinants, possibly Ca2+ channels, has a half‐life of between 2 and 36 hours. The results confirm our concepts that IgG antibody to nerve terminal determinants underlies the disorder of transmitter release in LEMS.