title: Histological determination of nitric oxide synthase (NOS) and NADPH-diaphorase in ragged-red fibers from patients with mitochondrial encephalomyopathies.
abstract: To determine localization of nitric oxide synthase in diseased muscle, we performed immunohistochemical analyses of neuronal-type nitric oxide synthase (nNOS) and endothelial-type nitric oxide synthase (ec-NOS) in biopsied muscles from five patients with mitochondrial encephalomyopathies. Immunostaining of nNOS was prominent in the sarcolemmal region of the ragged-red fibers, and weak in the sarcolemmal region of normal fibers. Immunostaining of ec-NOS was strongly positive in the myofibrils of ragged-red fibers. Ec-NOS immunoreactivity corresponded to fibers positive for SDH by histochemistry. Histochemical methods revealed prominent staining for NADPH-diaphorase on surface membranes of the ragged-red fibers. Findings suggest that nitric oxide is important in the muscles of patients with mitochondrial encephalomyopathies.
authors.affiliation: Department of Neurology, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Ohkoshi
authors.forename: H
authors.initials: H
authors.lastname: Mizusawa
authors.forename: T
authors.initials: T
authors.lastname: Fujita
authors.forename: S
authors.initials: S
authors.lastname: Shoji
mesh_terms: D000328:Adult; D002648:Child; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D007150:Immunohistochemistry; D017241:MELAS Syndrome / Q000201:enzymology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000201:enzymology / Q000473:pathology; D018482:Muscle, Skeletal / Q000201:enzymology / Q000473:pathology; D009252:NADPH Dehydrogenase / Q000032:analysis*; D019001:Nitric Oxide Synthase / Q000032:analysis*
chemical_list: D019001:Nitric Oxide Synthase; D009252:NADPH Dehydrogenase