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

---

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

The usual histologic pattern in acute viral hepatitis (AVH) includes cellular abnormalities predominantly in the perivenular (zone 3) hepatocytes and changes interpreted as representing regenerative activity in the periportal (zone 1) hepatocytes. Enzyme histochemical and ultrastructural studies of livers of 12 patients with AVH were undertaken to see whether these features support the concept of regeneration of hepatocytes in zone 1. The swollen hepatocytes in the perivenular areas were hydropic, with dilated or eccentric rough endoplasmic reticulum and decreased or vesicular smooth endoplasmic reticulum; correspondingly, the glucose-6-phosphatase activity (reflecting, when present, intact and functional endoplasmic reticulum) was markedly decreased. Succinic dehydrogenase and diphosphopyridine nucleotide diaphorase activities, representing mitochondrial enzymes, were limited to the perinuclear or pericanalicular cytoplasm of swollen hepatocytes. gamma-Glutamyl transpeptidase activity was increased. The periportal hydropic hepatocytes were small and arranged in clusters displacing sinusoids. Ultrastructurally, these hepatocytes had nearly normal organelles but scanty smooth endoplasmic reticulum. Activities of the enzymes glucose-6-phosphatase, succinic dehydrogenase, and diphosphopyridine nucleotide diaphorase were weak, although glycogen was abundant. gamma-Glutamyl transpeptidase activity was scanty in these hepatocytes. These findings from enzyme histochemical and electron microscopic studies could be interpreted as evidence of functional deterioration of perivenular swollen hepatocytes and relative functional immaturity of periportal hydropic clustered hepatocytes, suggesting regeneration of zone 1 hepatocytes.
...
PMID:Acute viral hepatitis: morphologic and functional correlations in human livers. 669 43

The diurnal rhythms of the microsomal flavoprotein NADPH-cytochrome c reductase activity, of diaphorase and of succinic dehydrogenase are presented. Minimum levels are ascertained at 09(00), maximum levels at 21(00). The concentration of mitochondrial radicals as a function of the time of day is also demonstrated. Here too the minimum is at 09(00) and the maximum between 15(00) and 21(00). On the other hand, GSH levels are found to be high between 09(00) and 12(00) and low in the evening. Thus a causative relationship between the concentration of cellular radicals, which originate in flavin enzymes, and the concentration of the tripeptide glutathione is assumed.
...
PMID:Flavin enzymes, mitochondrial radicals and reduced glutathione in daily rhythmic dependency. 677 1

Histochemical studies have been made of the isocitrate dehydrogenase, succinic dehydrogenase, malate dehydrogenase, glutamate dehydrogenase, DPN diaphorase, TPN diaphorase, delta 5-3 beta-hydroxysteroid dehydrogenase and monoamine oxidase in the caput, corpus and cauda epididymides of normal and alpha chlorohydrin (6.5 mg/kg/9 days) treated rats. Administration of alpha chlorohydrin in a low dose caused a conspicuous decrease in all these enzymes except delta 5-3 beta-HSD, in various cell types of epididymal epithelium and sperms. Biochemical estimations of isocitrate dehydrogenase, succinic dehydrogenase, malate dehydrogenase and delta 5-3 beta-HSD have further supported and confirmed these histochemical observations. These changes in enzyme activities after treatment with low dose of alpha chlorohydrin strongly suggest that TCA cycle and amino acid metabolism of epididymis become defective, much earlier before any histological damage to the epididymis becomes visible.
...
PMID:Effects of low doses of alpha chlorohydrin on the dehydrogenases and oxidases of rat epididymal epithelium and sperms: a correlative histochemical and biochemical study. 694 44

Androgen level and the activity of lactate dehydrogenase, succinic dehydrogenase, 17 beta-hydroxysteroid dehydrogenase and NADP-diaphorase was studied in cultured Leydig cells obtained from testes of male mice from inbred strains KP and CBA following a single injection of cadmium chloride. Mice from CBA strain, known to be resistant to the toxic effects of cadmium showed no differences in the enzyme activity and endocrine function of gonads, as compared with control animals. In KP mice, sensitive to cadmium, a marked decrease of activity of all studied dehydrogenases, as well as a fall of androgen level was observed following cadmium administration. The decrease of hormone secretion occurred on the 2nd day of tissue culture and showed a correlation with the 17 beta-hydroxysteroid dehydrogenase activity.
...
PMID:Effect of cadmium on androgen level and oxidoreductive enzymes activity in cultured leydig cells of KP and CBA mice. 694 54

The quantitative cytochemical investigation of the prodigiozan effect on the enzymatic activity of the peritoneal macrophages was performed on mice. The drug was administered in a single dose of 150 microgram/kg 24 hours before the specimen collection. Prodigiozan promoted a reliable increase in the activity of the enzymes participating in glycolysis (lactate and cytoplasmic alpha-glycerophosphate dehydrogenases), hexoso-monophosphatic pathway of glucose oxidation (glucoso-6-phosphate dehydrogenase), succinate dehydrogenase, NADP. N-diaphorase and lysosomal enzymes, such as acid phosphatase and non-specific alpha-naphthyl acetate esterase. The changes indicate that activation of the macrophages is one of the significant mechanisms of increasing the host nonspecific resistance with prodigiozan.
...
PMID:[Prodigiozan as an activator of peritoneal macrophages]. 727 Dec 60

The mitochondrion is the only extranuclear organelle containing DNA (mtDNA). As such, genetically determined mitochondrial diseases may result from a molecular defect involving the mitochondrial or the nuclear genome. The first is characterized by maternal inheritance and the second by Mendelian inheritance. Ragged-red fibers (RRF) are commonly seen with primary lesions of mtDNA, but this association is not invariant. Conversely, RRF are seldom associated with primary lesions of nuclear DNA. Large-scale rearrangements (deletions and insertions) and point mutations of mtDNA are commonly associated with RRF and lactic acidosis, e.g. Kearns-Sayre syndrome (KSS) (major large-scale rearrangements), Pearson syndrome (large-scale rearrangements), myoclonus epilepsy with RRF (MERRF) (point mutation affecting tRNA(lys) gene), mitochondrial myopathy, lactic acidosis, and stroke-like episodes (MELAS) (two point mutations affecting tRNA(leu)(UUR) gene) and a maternally-inherited myopathy with cardiac involvement (MIMyCa) (point mutation affecting tRNA(leu)(UUR) gene). However, RRF and lactic acidosis are absent in Leber hereditary optic neuropathy (LHON) (one point mutation affecting ND4 gene, two point mutations affecting ND1 gene, and one point mutation affecting the apocytochrome b subunit of complex III), and the condition associated with maternally inherited sensory neuropathy (N), ataxia (A), retinitis pigmentosa (RP), developmental delay, dementia, seizures, and limb weakness (NARP) (point mutation affecting ATPase subunit 6 gene). The point mutations in MELAS, MIMyCa, and MERRF, and the large-scale mtDNA rearrangements in KSS and Pearson syndrome have a broader biochemical impact since these molecular defects involve the translational sequence of mitochondrial protein synthesis. The nuclear defects involving mitochondrial function generally are not associated with RRF. The biochemical classification of mitochondrial diseases principally catalogues these nuclear defects. This classification divides mitochondrial diseases into five categories. Primary and secondary deficiencies of carnitine are examples of a substrate transport defect. A lipid storage myopathy is often present. Disturbances of pyruvate or fatty acid metabolism are examples of substrate utilization defects. Only four defects of the Krebs cycle are known: fumarase deficiency, dihydrolipoyl dehydrogenase deficiency, alpha-ketoglutarate dehydrogenase deficiency, and combined defects of muscle succinate dehydrogenase and aconitase. Luft disease is the singular example of a defect in oxidation-phosphorylation coupling. Defects of respiratory chain function are manifold. Two clinical syndromes predominate, one involving limb weakness, and the other primarily affecting brain function. Leigh syndrome may result from different enzyme defects, most notably pyruvate dehydrogenase complex deficiency, cytochrome c oxidase deficiency, complex I deficiency, and complex V deficiency associated with the recently described NARP point mutation. A new group of mitochondrial diseases has emerged.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:The expanding clinical spectrum of mitochondrial diseases. 833 7

Using two-dimensional gel electrophoresis and N-terminal amino acid sequencing analysis, we demonstrate that a mutant of the global regulatory protein ArcA fails to decrease the synthesis of the TCA cycle enzymes malate dehydrogenase, isocitrate dehydrogenase, lipoamide dehydrogenase E3 and succinate dehydrogenase in response to stasis, while the increased production of the glycolysis enzymes phosphoglycerate mutase and pyruvate kinase is unaffected. Microcalorimetric and respiratory measurements show that the continued production of TCA cycle enzymes in the (delta)arcA mutant is manifested as an elevated rate of respiration and total metabolic activity during starvation. The (delta)arcA mutant is severely impaired in surviving prolonged periods of exogenous carbon starvation, a phenotype that can be alleviated by overproducing the superoxide dismutase SodA. In addition, flow cytometry demonstrates that starving (delta)arcA mutant cells, in contrast to wild-type cells, fail to perform reductive division, remain large and contain multiple chromosomal copies. We suggest that the ArcA-dependent reduced production of electron donors and the decreased level and activity of the aerobic respiratory apparatus during growth arrest is an integral part of a defense system aimed at avoiding the damaging effects of oxygen radicals and controlling the rate of utilization of endogenous reserves.
...
PMID:Bacterial defense against aging: role of the Escherichia coli ArcA regulator in gene expression, readjusted energy flux and survival during stasis. 867 Aug 22

The genes encoding succinate dehydrogenase (sdhCDAB), the specific components of the 2-oxoglutarate dehydrogenase complex (ODH, E1o and E2o; sucAB) and succinyl-CoA synthetase (sucCD) form a cluster containing two promoters at 16.3 min in the chromosome of Escherichia coli: Psdh sdhCDAB-Psuc sucAB-sucCD. The gene encoding the lipoamide dehydrogenase component of both the 2-oxoglutarate and pyruvate dehydrogenase complexes (E3; lpdA) is the distal gene of another cluster containing two promoters located at 2.7 min: Ppdh pdhR-aceEF-Plpd lpdA. The responses of the suc and lpd promoters to different environmental conditions and to regulator defects were investigated with appropriate lacZ fusions, in order to understand how expression of the sucAB genes is co-regulated with other genes in the sdhCDAB-sucABCD cluster and with lpdA expression. Expression from the suc promoter was repressed by IHF and partially activated by sigma 38 but it was not regulated by ArcA, FNR, CRP, FruR or Fis, and not repressed by glucose or anaerobiosis, indicating that the well-established catabolite and anaerobic repression of ODH synthesis is imposed elsewhere. In contrast, the lpd promoter was repressed by both glucose (via a CRP-independent mechanism) and anaerobiosis (mediated by ArcA), and activated by Fis, but it was not regulated by FNR, FruR, IHF or sigma 38. These observations support the view that transcription of the sucABCD genes is primarily initiated and regulated at the upstream sdh promoter, and that the lpd promoter is independently co-regulated with Psdh (primarily by ArcA-mediated repression) rather than with Psuc. Direct evidence for co-transcription of the entire sdhCDAB-sucABCD region from Psdh was obtained by detecting a 10 kb transcript in rnc and rne mutants, but not in the parental strains. Three RNaseIII-specific processing sites, which contribute to the extreme instability of the readthrough transcript, were identified in the sdhCDAB-sucABCD intergenic region. Other sites of endonuclease processing were located by interpreting the patterns of transcript subfragments observed in Northern blotting.
...
PMID:Transcription and transcript processing in the sdhCDAB-sucABCD operon of Escherichia coli. 972 32

Cytochemical reactions for mitochondrial NADH-dependent dehydrogenases (diaphorase/NADH which is related to flavoprotein), NAD-dependent dehydrogenases (isocitrate, malate) and succinate dehydrogenase were carried out in rat spermatozoa. In addition to a morphological evaluation, the intensity of the reactions was assessed using a computer image analysing system (Quantimet 600 S). The intensity of the reactions was examined in sperm midpieces by measuring integrated optical density (IOD) and mean optical density (MOD). The activity of mitochondrial respiratory chain complexes was also analysed using the polarographic method. In the population of spermatozoa studied, all whole spermatozoa midpieces were completely filled with formazans, the product of the cytochemical reaction. These morphological findings corresponded to the values obtained for IOD and MOD for the given enzymes. In the oxygraphic studies, the spermatozoa demonstrated consumption of oxygen in the presence of substrates for I, II and IV complexes and their mitochondria revealed normal integrity and sensitivity to the substrates and inhibitors. However, the oxygraphic studies revealed differences between the sperm and somatic cells. These differences concerned the stimulation of pyruvate oxidation by malate, the lack of an effect of malonic acid on phenazine methosulphate (an acceptor of electrons) oxidation and the lack of an effect of cytochrome c on ascorbate oxidation. The cytochemical method, together with densitometric measurements, enables: (1) the reaction intensity to be determined objectively; (2) subtle and dramatic differences in reaction intensity to be revealed between spermatozoa that do not differ under morphological evaluation of the intensity; (3) possible defects within the mitochondrial sheath to be located and assessed in a large number of spermatozoa. This method can be used as a screening method alongside the routine morphological examination of spermatozoa. On the other hand, the oxygraphic method in the inner membrane of mitochondria can reveal functional changes which are related to the action of respiratory chain complexes and display characteristic features of mitochondria energy metabolism. The methods used are complementary and allow the complex evaluation of mitochondria in spermatozoa. Both methods can be used in experimental and clinical studies.
...
PMID:Computerized analysis of cytochemical reactions for dehydrogenases and oxygraphic studies as methods to evaluate the function of the mitochondrial sheath in rat spermatozoa. 1116 13

Nitric oxide synthase-1 (NOS-1) is found in high concentrations in skeletal muscles, where its synthesis product nitric oxide (NO) is reported to be involved in a number of processes, including the modulation of the oxidative metabolism of myofibers. Performing immunoblot analysis and quantification of formazan produced by its specific NADPH diaphorase activity, we found NOS-1 to be enriched in rat skeletal muscles with a high proportion of fast-twitch myofibers. Since these myofibers represent a metabolically heterogeneous subpopulation, we extended our investigation to the level of individual myofibers. Using serial sections we combined myosin heavy chain-based fiber-typing with quantitative succinate dehydrogenase histochemistry to determine three groups of fiber-types, comprising fast-oxidative, fast-glycolytic and slow-oxidative myofibers. Image analysis showed that NOS-1 diaphorase activity is significantly enriched in fast-oxidative myofibers compared with fast-glycolytic and slow-oxidative ones. In order to characterize potential biological effects of the fiber-type-specific enrichment of NOS-1, we performed cytochrome oxidase histochemistry in the presence of the NO donors NOC-9 and SNAP. Both NO donors reduced cytochrome oxidase activity in all myofibers investigated with almost identical semi-maximal inhibition rates, although fast-oxidative and slow-oxidative myofibers contained twice as much basal catalytic activity than fast-glycolytic ones. In summary, we suggest that the NOS-1/NO system of skeletal muscles exerts its biological role especially in fast-oxidative myofibers, since these myofibers express more NOS-1 than fast-glycolytic or slow-oxidative ones and also contain the highest concentrations of cytochrome oxidases as potential target molecules of NO.
...
PMID:Nitric oxide synthase-1 is enriched in fast-twitch oxidative myofibers. 1170 44


<< Previous 1 2 3 4 5 6 7 8 9 Next >>

---