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“All‐or‐none” cytochrome C oxidase positivity in mitochondria in chronic progressive external ophthalmoplegia: An ultrastructural—cytochemical study
Author(s) -
Matsuoka Taro,
Goto YuIchi,
aka Ikuya
Publication year - 1993
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880160215
Subject(s) - chronic progressive external ophthalmoplegia , cytochrome c oxidase , mitochondrion , ultrastructure , external ophthalmoplegia , mitochondrial dna , biology , pathology , medicine , mitochondrial myopathy , biochemistry , anatomy , gene
Teased single muscle fibers from 6 patients with chronic progressive external ophthalmoplegia (CPEO) showed a segmental defect in cytochrome c oxidase (COX) activity. On ultrastructural–cytochemical examination, the majority of mitochondria in COX‐positive segments were COX‐positive, whereas all mitochondria in COX‐negative segments were COX‐negative. This “all‐or‐none” COX positivity in mitochondria in CPEO with deleted mitochondrial DNA can be explained by the “threshold effect,” which induces the tissue‐specific involvement and clinical heterogeneity. © 1993 John Wiley & Sons, Inc.