Mosaicism of mitochondria in mitochondrial myopathy : an electronmicroscopic analysis of cytochrome c oxidase

• Published in: Acta neuropathologica 1990-10, Vol.80 (6), p.642-648
• Main Authors: HAGINOYA, K, MIYABAYASHI, S, IINUMA, K, TADA, K
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Child; Diseases of striated muscles. Neuromuscular diseases; Electron Transport Complex IV - immunology; Electron Transport Complex IV - ultrastructure; Female; Histocytochemistry; Humans; Immunohistochemistry; Infant, Newborn; Medical sciences; Microscopy, Electron; Mitochondria, Muscle - enzymology; Mitochondria, Muscle - ultrastructure; Muscles - enzymology; Muscles - pathology; Muscles - ultrastructure; Muscular Diseases - enzymology; Muscular Diseases - pathology; Neurology
• ISSN: 0001-6322; 1432-0533
• DOI: 10.1007/BF00307633

Electron microscopic histochemistry was applied to the study of cytochrome c oxidase activity in each mitochondrion of biopsied muscles from four patients with mitochondrial myopathy [one case of fatal infantile mitochondrial myopathy, one case of myoclonus epilepsy associated with ragged-red fibers (MERRF), and two cases of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS)]. In the patient with fatal infantile mitochondrial myopathy, intercellular heterogeneity of mitochondria was recognized. In the three patients with either MERRF or MELAS, cytochrome c oxidase activity was segmentally changed from positive to negative within single muscle fibers. In the two patients with MELAS, small groups of positive-stained mitochondria were located among negative-stained mitochondria in the negative segment of a few muscle fibers. These findings revealed that there were heterogeneous populations of normal and abnormal mitochondria intracellularly or intercellularly within the muscles of these patients.