Mosaicism of mitochondria in mitochondrial myopathy: an electronmicroscopic analysis of cytochrome c oxidase.
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.
Haginoya
K
K
Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan.
Miyabayashi
S
S
Iinuma
K
K
Tada
K
K
D000328:Adult; D002648:Child; D003576:Electron Transport Complex IV / Q000276:immunology / Q000648:ultrastructure*; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D007150:Immunohistochemistry; D007231:Infant, Newborn; D008854:Microscopy, Electron; D008931:Mitochondria, Muscle / Q000201:enzymology / Q000648:ultrastructure*; D009132:Muscles / Q000201:enzymology / Q000473:pathology / Q000648:ultrastructure; D009135:Muscular Diseases / Q000201:enzymology / Q000473:pathology*
D003576:Electron Transport Complex IV