Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.3.5.1 (succinate dehydrogenase)
8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mitochondrial myopathies are morphologically characterized by ragged-red fibres (RRF). Serial cross-section revealed that the ragged-red appearance was only focal. This is in agreement with a partial cytochrome c oxidase (COX) deficiency in chronic progressive external ophthalmoplegia (CPEO). Since most of these patients show deletions of the mitochondrial genome single fibre analyses were performed determining COX and succinate dehydrogenase (SDH) in serial muscle sections from two patients with CPEO. High SDH activity was demonstrated in RRF; in contrast COX activity was lower in RRF in a patient, possibly representing a focal assembly of mitochondria with deletions in their genomes. The variation of enzyme activities along the muscle fibre was especially high in RRF. This study presents the first quantitative evidence that enzyme activities vary considerably along fibres in muscle from patients with a mitochondrial myopathy.
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PMID:Enzyme activity analyses along ragged-red and normal single muscle fibres. 133 Sep 95

The strongly succinate dehydrogenase-reactive blood vessels (SSV) are shown to have increased numbers of enlarged mitochondria in smooth muscle cells of the vessel wall on electron microscopy. They are seen in biopsied skeletal muscles from patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) at high frequency. The present study was done to examine the incidence of SSV in biopsied muscles from various neuromuscular diseases. Among 107 patients with mitochondrial encephalomyopathies (MEM) including 50 with chronic progressive external ophthalmoplegia (CPEO), 7 with myoclonus epilepsy with ragged-red fibers (MERRF), and 50 with MELAS, SSV were seen in nearly a half of the patients, and comprised approximately 24% of small arteries. On the other hand, SSV in 100 patients with various neuromuscular diseases other than MEM were exceptional, and only one of 8 patients with myotonic dystrophy had SSV. These findings suggest that the SSV are induced by functional abnormality of mitochondria in smooth muscle cells, and that an identification of the SSV is an additional crucial evidence to make a pathological diagnosis of MEM.
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PMID:[Strongly succinate dehydrogenase-reactive blood vessels (SSV) in various neuromuscular diseases]. 142 48

Vascular involvement in biopsied muscle specimens from 11 patients with chronic progressive external ophthalmoplegia (CPEO) with ragged-red fibers (RRF) was studied. Almost none of 69 intramuscular arteries examined were strongly stained with succinate dehydrogenase (SDH) except one patient who had 2 SSV (strongly SDH-reactive blood vessels) in his muscle biopsy. Although RRF and focal cytochrome c oxidase (CCO) deficiency in muscle fibers were the common histochemical changes in muscle biopsy specimens from CPEO patients, all mitochondria in both endothelial and smooth muscle cells of the arteries had normal morphology except for the two SSV and all mitochondria in the blood vessels had normal CCO activity by electron cytochemistry. The findings obtained from the present study were quite different from those in mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), and myoclonus epilepsy associated with ragged-red fibers (MERRF) in which the striking vascular involvement with SSV is the most common and major abnormality in muscle biopsy specimens. To study vascular involvement in mitochondrial encephalomyopathies is the one of very important clues to understand the pathophysiology of phenotypic expressions in mitochondrial encephalomyopathies.
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PMID:[Vascular pathology in chronic progressive external ophthalmoplegia with ragged-red fibers]. 161 73

We studied a large family with a dominantly inherited mitochondrial myopathy characterized by progressive external ophthalmoplegia, dysphagia, cataract, lactic acidosis, exercise intolerance, and early death. Morphologic studies of muscle biopsies suggested mitochondrial heteroplasmy and revealed ragged-red fibers and decreased histochemical reactions for cytochrome c oxidase and succinate dehydrogenase. Biochemistry showed a partial defect of cytochrome c oxidase and a mild generalized reduction of other mitochondrial enzymes requiring mitochondrial DNA-encoded subunits. Southern blot analysis and PCR amplification showed mitochondrial DNA deletions in muscle of all affected members, but not in lymphocytes or fibroblasts, suggesting a tissue-specific distribution. Deletions were multiple and seemed to increase with time and to correlate with the severity of the disease.
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PMID:Dominantly inherited mitochondrial myopathy with multiple deletions of mitochondrial DNA: clinical, morphologic, and biochemical studies. 206 33

Ragged-red fibers (RRFs) are mainly seen in mitochondrial myopathy and related to biochemical defects in electron transfer chain on some occasions. Recently, some papers reported the occurrence of RRFs in the biopsied muscle of myotonic dystrophy (MyD). To examine whether the mitochondrial function is disturbed in MyD, we have studied the biopsied muscles of 12 cases with MyD (10 males and 2 females averaging 38 years of age) morphologically and mainly biochemically. RRFs, ranging from 2--20% of the muscle fibers, were identified in 5 out of 12 cases. On electron microscopy, these fibers had aggregated abnormally enlarged mitochondria with dene bodies, concentrically whirled membranous cristae and paracrystalline inclusions. Clinically, 4 of 5 cases with RRFs had mild to moderate and only 2 of 7 without RRFs had ophthalmoplegia. Bicycle ergometer exercise test showed abnormal increase of lactate/pyruvate ratio in three cases with RRFs. Histochemically, cytochrome c oxidase (CCO) activity was absent selectively in all of the RRFs. Immunohistochemical staining showed the presence of CCO protein by using monoclonal antibody which was specific to CCO subunit IV. Biochemical study with crude muscle extract of 11 cases of MyD showed decreases in NADH dehydrogenase, NADH CoQ reductase, succinate CoQ reductase (SCR), CCO, carnitine actyl transferase activities in most of cases regardless RRFs. To avoid the influence possibly derived from the various stages of muscle degeneration in the biopsied specimens, we calculated the ratio of the enzyme activities compared with succinate dehydrogenase which was located in the electron transfer chain and did not show any statistical difference regardless of RRFs.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[A study of mitochondrial electron transfer chain in myotonic dystrophy]. 259 36

A 25-year-old woman with Kearns-Sayre syndrome (KSS) had complete external ophthalmoplegia, short stature, ataxia, cardiac conduction defects, and pigmentary retinopathy. Muscle biopsy revealed ragged-red fibers. Electron microscopy showed increased numbers of mitochondria with disordered structure and paracrystalline inclusions. Enzymatic analysis revealed a deficiency of complex II of the mitochondrial respiratory chain, and, more specifically, a deficiency of succinic dehydrogenase, although both subunits of this enzyme proved to be present by immunologic analysis. Therapy with vitamin cofactors did not result in short-term improvement. This appears to be the first report of complex II deficiency in a patient with KSS.
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PMID:Kearns-Sayre syndrome and complex II deficiency. 271 Mar 60

Single-fiber analyses using a kinetic microphotometric method were performed on three patients with chronic progressive external ophthalmoplegia and proximal myopathy accompanied by a partial deficiency of cytochrome c oxidase. Two patients had subsarcolemmal accumulation of mitochondria (ragged-red fibers). Qualitative histochemical demonstration of cytochrome c oxidase showed a mosaic of fibers without detectable cytochrome c oxidase activity. Quantitative single fiber measurements in the patients' biopsies showed that the majority of the muscle fibers had decreased cytochrome c oxidase activity without selective involvement of a specific fiber type. Succinate dehydrogenase was measured and the ratio of the activities (succinate dehydrogenase/cytochrome c oxidase) was calculated. Normal muscle showed a ratio of about 2, whereas diseased muscle showed values between 10 and 20, due to a decrease in cytochrome c oxidase activity. Ragged-red fibers showed very low or undetectable cytochrome c oxidase activity.
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PMID:Enzyme activity measured in single muscle fibers in partial cytochrome c oxidase deficiency. 282 55

A case of mitochondrial enzymopathy, called also ophthalmoplegia plus, was observed in a 31-year-old man. Histoenzymatic investigations demonstrated in the myocytes decreased and irregularity of reactions for succinic dehydrogenase, tetrazole reductase and mitochondrial ATPase. In electron microscopy paracrystalline structures, lamellar bodies and concentrically condensed cristae were seen in the mitochondria, and increased glycogen stores outside the mitochondria.
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PMID:[A case of mitochondrial enzymopathy]. 297 67

The evaluation of the severity of progressive external ophthalmoplegia (PEO) with ragged-red fibers in muscle, at the onset of the disease, when PEO is most often the only presenting symptom, is a difficult problem in neurological practice. In order to address that issue, we have performed a comparative analysis of the clinical, morphological and molecular characteristics of 43 patients affected with that form of ocular myopathy. Quantification of mitochondrial accumulation was performed with an image analysis application on muscle sections stained with succinate dehydrogenase histochemical reaction. The proportion of muscle fibres appearing as cytochrome c oxidase deficient was used as an index of the muscle-energy defect. Muscle mitochondrial DNA deletions were detected, localized and quantitated by Southern blot analysis. Point mutations were screened in five transfer RNA genes in the mtDNA (tRNA(Leucine (UUR)), tRNA(Lysine), tRNA(Glutamine), tRNA(Isoleucine) and tRNA(Formylmethionine)) by a denaturing gradient gel electrophoresis technique. This investigation confirmed the high frequency of mtDNA deletions or point mutations in PEO. At the onset of the disease, no clinical, morphological or molecular features could predict whether PEO would remain isolated or become part of a more severe multisystem disease. However, patients with mtDNA deletions were characterized by more severe ophthalmoplegia of earlier onset. Their muscle alterations were roughly parallel in severity to the proportion of deleted mtDNA molecules in muscle. Patients with a multitissular disease and mtDNA deletions were always sporadic cases and their clinical presentation was, most often, closely related to Kearns Sayre syndrome.
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PMID:Chronic progressive external ophthalmoplegia with ragged-red fibers: clinical, morphological and genetic investigations in 43 patients. 749 74

Using in situ hybridization, we studied muscle biopsy specimens from 4 patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). Three of the 4 patients with MELAS had a mutation at position 3243 of mitochondrial DNA (mtDNA) in the transfer RNALeu(UUR) gene, and the other patient had a mutation at position 3271 in the same transfer RNALeu(UUR) gene. Quantitative analysis using Southern blot hybridization and polymerase chain reaction showed 80 to 90% mutant mtDNA in muscle. In situ hybridization analysis showed that total mtDNAs (both normal and mutant) were extremely increased in blood vessels with high succinate dehydrogenase activity (strongly succinate dehydrogenase-reactive blood vessels) and ragged-red fibers. Cytochrome c oxidase activity in most of these reactive blood vessels and ragged-red fibers was positive. The similar morphological behavior in these vessels and fibers suggests that an increase in mutant mtDNA is responsible for mitochondrial proliferation and dysfunction in both tissues where cytochrome c oxidase is not a primarily defective enzyme. The pattern of expression of genes for mtDNA-encoded ribosomal RNA and the protein-coding region cytochrome c oxidase subunit II were similar in muscle specimens of patients with MELAS, patients with chronic progressive external ophthalmoplegia, and normal control subjects, and also between the two MELAS mutations. These results do not support the hypothesis that impaired transcription termination is a molecular defect in MELAS.
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PMID:Increased mitochondrial DNA in blood vessels and ragged-red fibers in mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). 768 81


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