重症筋無力症の神経筋接合部の電顕的観察

ELECTRON MICROSCOPIC OBSERVATION OF NEUROMUSCULAR JUNCTION IN MYASTHENIA GRAVIS

Ｉ．はじめに

　重症筋力症は横紋筋の易労性および脱力と，それらの症状が休息することにより改善されるという臨床的特徴を有している。その本態についてはまだ不明であるが，神経筋接合部の傷害によると考えられている。

　本症の神経筋接合部に関する病理学的研究はOppen—heim^1）によつて初めて報告されている。その後，Woolfら^2）を始め光顕および組織化学に関する報告^{3）4）5）21）}がなされている。

The case of an 43-year-old male with the myas-thenia gravis was studied with light & electron microscopy, and the muscle biopsies were taken from the intercostal muscles at the time of crisis and thymectomy.

Changes in the muscle fibers were resemble with those seen in other neural muscle diseases.

Fine structure abnormalities of neuromuscular junctions were consisted of decreasing numbers of secondary synaptic clefts, decreasing numbers of synaptic vesicles, and fewer mitochondria in the area of the sole plate. The dense body was also observed in the terminal axon, and their significance was disscusseed.

From the observed abnormalities in the fine struc-ture of neuromuscular junctions, it was suggested that presynaptic lesion was significant in the myas-thenia gravis, though any primary defect was not detected with electron microscope.