CONGENITAL MYASTHENIC SYNDROMES .1. DEFICIENCY AND SHORT OPEN-TIME OF THE ACETYLCHOLINE-RECEPTOR
CONGENITAL MYASTHENIC SYNDROMES .1. DEFICIENCY AND SHORT OPEN-TIME OF THE ACETYLCHOLINE-RECEPTOR
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DOI：
10.1002/mus.880161204
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发表时间：
1993-12-01
期刊：
影响因子：
3.4
通讯作者：
WAISBURG, HA
中科院分区：
文献类型：
--
作者：
ENGEL, AG;NAGEL, A;WAISBURG, HA
一名5.5岁女孩自出生以来就有肌无力症状。抗乙酰胆碱受体（AChR）抗体试验阴性。为了研究神经肌肉传递缺损的特点，我们在27个月大时获得了肋间肌标本。终板未见免疫沉积。电镜下大部分突触后区正常，但结褶上的AChR密度弥漫性降低。体外微电极研究显示，神经冲动释放的递质量子数正常。终板电位和电流的微缩幅度异常低。通过分析乙酰胆碱诱导的电流噪声对AChR的动力学特性进行了研究，结果表明AChR的平均通道打开时间显著降低；平均通道电导正常。在这种疾病中，神经肌肉传递的安全范围可能因AChR的缺乏和异常的动力学特性而受到损害。这些发现在迄今为止所描述的先天性AChR缺乏症患者中是独一无二的。1993 John Wiley & Sons, Inc.；
A 5.5-year-old girl had myasthenic symptoms since birth. Tests for antiacetylcholine receptor (AChR) antibodies were negative. To investigate the character of the neuromuscular transmission defect, an intercostal muscle specimen was obtained at age 27 months. Immune deposits were absent from the endplates. On electron microscopy, most postsynaptic regions appeared normal, but the density of AChR on the junctional folds was diffusely reduced. In vitro microelectrode studies revealed that the number of transmitter quanta released by nerve impulse was normal. The amplitude of miniature of endplate potentials and currents was abnormally low. A study of the kinetic properties of AChR by analysis of acetylcholine-induced current noise demonstrated a significant decrease in mean channel open-time; the mean channel conductance was normal. The safety margin of neuromuscular transmission in this disorder is likely to be compromised by the deficiency and abnormal kinetic properties of AChR. The findings are unique among those patients with congenital AChR deficiency described to date. (C) 1993 John Wiley & Sons, Inc.