THE MYOTONIC MOUSE MUTANT ADR - ELECTROPHYSIOLOGY OF THE MUSCLE-FIBER
THE MYOTONIC MOUSE MUTANT ADR - ELECTROPHYSIOLOGY OF THE MUSCLE-FIBER
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DOI：
10.1002/mus.880110505
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发表时间：
1988-05-01
期刊：
影响因子：
3.4
通讯作者：
JOCKUSCH, H
中科院分区：
文献类型：
--
作者：
MEHRKE, G;BRINKMEIER, H;JOCKUSCH, H
小鼠的遗传性神经肌肉综合征，“平直反应发育受阻”（ADR），以骨骼肌收缩后为特征。为了分析这种遗传缺陷的病因，细胞内记录研究了突变型和野生型肌纤维。直接刺激ADR肌纤维可引起持续1-5秒的动作电位，其振幅下降，频率变化。电后活动与纤维后收缩一致，这两种现象都可以被膜稳定药物托卡因抑制。由于在无氯化物培养基中野生型肌肉中观察到类似的APs，因此研究了氯化物电导在ADR综合征中的可能参与。野生型肌肉的膜时间常数在无氯培养基中延长4倍，而ADR肌肉的膜时间常数仅延长1.4倍。这一发现表明ADR肌膜的氯离子电导急剧降低。我们认为ADR是一种肌强直，其病因与遗传性肌强直有关。
The hereditary neuromuscular syndrome of the mouse, "arrested development of righting response" (ADR), is characterized by after-contractions of skeletal muscle. In order to analyze the etiology of this hereditary defect, mutant and wildtype muscle fibers were studied by intracellular recording. Direct stimulation of ADR muscle fibers elicited runs of action potentials of 1-5 seconds duration, with declining amplitudes and varying frequencies. The electrical after-activity coincided with after-contractions of the fiber, and both phenomena could be suppressed by the membrane-stabilizing drug tocainide. Since similar runs of APs were observed with wildtype muscle in chloride-free medium, the possible involvement of chloride conductance in the ADR syndrome was studied. Although membrane time constants in wildtype muscle were 4 times prolonged in chloride-free medium, those of ADR muscle were only 1.4 times longer. This finding indicated a drastic reduction of chloride conductance of the ADR muscle membrane. We conclude that ADR is a myotonia, related in its etiology to hereditary myotonias of man.