Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q8NEX9 (reductase)
 26,410 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present findings provide experimental evidence for the hypothesis that compromised cellular defense mechanisms, i.e., glutathione (GSH), GSH-peroxidase and catalase in the brain may be involved in neuronal degeneration caused by manganese (Mn) neurotoxicity. Moreover, data are presented demonstrating that the striatum is particularly susceptible to the deleterious effects of Mn. Specifically, exposure to subchronic MnCl2 produced significant reductions in GSH-peroxidase activity in the cytosol and mitochondrial fractions of the whole brain and the striatum. The decrease in GSH-peroxidase was most pronounced in the mitochondrial fraction of the striatum where the activity was reduced to 35% of the control. Catalase activity was also decreased in the striatum of rats treated with Mn but not in the whole brain. GSH content was markedly depleted (20% of the control) in the striatum, although only modestly decreased in whole brain (80% of the control). The alterations in the above parameters were accompanied by depletion of dopamine and dopamine metabolites in the striatum. The treatment of rats with Mn also decreased the activity of oxidized glutathione-reductase; the same treatment increased the activity of gamma-glutamyltranspeptidase. The activity of gamma-glutamylcysteine synthetase was not altered by Mn. The possible relevancy of the findings of this study to understanding the mechanism of Mn neurotoxicity of dopamine systems is discussed.
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PMID:Selective vulnerability of glutathione metabolism and cellular defense mechanisms in rat striatum to manganese. 290 11

The unprecedented ability of cyclosporin A, when given for six days at a dose of 25 mg/kg/d or 50 mg/kg/d, to cause a marked and sustained increase in renal glutathione (GSH) concentration in rat kidney is described. This response was particular to the kidney insofar as the GSH concentration in the liver was not increased in response to a lower dose of cyclosporin and was decreased in the liver of animals treated with the higher dose of the drug. The increase in kidney GSH concentration did not appear to be due to an increased rate of production or to an inhibition of the degradation of the tripeptide. This suggestion is based on the finding that the activities of the GSH synthesis pathways, GSSG-reductase and gamma-glutamylcysteine synthetase, were unchanged or decreased, respectively, and those of the catabolic enzymes, GSH-peroxidase and gamma-glutamyltranspeptidase, were unchanged or increased, respectively. It is suggested that the elevation of renal GSH content in the face of diminished synthetic capacity and an apparent increased utilization may result from an enhanced uptake of GSH as the result of alterations caused by cyclosporin in the renal transport system.
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PMID:Cyclosporin-mediated increase in kidney glutathione and effects on gamma-glutamyl-cycle enzymes. 290

Rat hepatic microsomal and 100,000 g supernatant fractions catalyzed an NADH- and FMN-dependent reduction of amine oxides. Horseradish peroxidase (HRP) served as a model for the amine oxide reductase located in rat hepatic 100,000 g supernatant fraction. The HRP-catalyzed reaction displayed saturation kinetics with respect to NADH and the amine oxide substrate; however, there was an optimum concentration for FMN after which inhibition was observed at increased concentrations of FMN. The reductase in the 100,000 g hepatic supernatant fraction closely paralleled HRP-catalyzed amine oxide reduction in coenzyme requirements, sensitivity to inhibitors, and substrate specificity. Moreover, the peroxidase activity of HRP and microsomal and 100,000 g supernatant fractions correlated with the NADH- and FMN-dependent amine oxide reductase activities of these enzyme preparations. The NADH- and FMN-dependent amine oxide reductase activity in 100,000 g supernatant fractions, however, did not parallel the aldehyde oxidase activity. Thus, the results indicate that there is an amine oxide reductase in rat hepatic 100,000 g supernatant fraction with catalytic properties that are modeled well by horseradish peroxidase.
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PMID:Peroxidase as a model for reduction of tertiary amine oxides catalyzed by rat hepatic supernatant and microsomal fractions. 291 14

The vulvar epithelial lesions which have been subjected to histological examinations in Nagasaki University Hospital (1965-1985) and its 5 affiliated hospitals (1975-1985) included 133 cases in vulvar dystrophies, 72 in other benign lesions, 18 in squamous cell carcinoma in situ, 10 in vulvar Paget's disease, and 59 in invasive carcinoma. These lesions were studied pathologically and endocrinologically, and the pathogenesis of vulvar carcinoma and whose clinical problems were discussed. Serum hormone level in lichen sclerosus In a lichen sclerosus group, serum testosterone level was higher, as compared to that of a coetaneous group in the control, and androstenedione remained normal whereas 5 alpha-dihydrotestosterone (DHT) was decreased significantly. This led us to apply a 2% testosterone propionate ointment to the local skin, and which resulted in an apparent increase in DHT; the greater the increase multiple, the more the significance in clinical efficacy; suggesting that application of testosterone ointment may lead to the activation of 5 alpha-reductase and subsequently to an increase in DHT by which clinical symptoms also were alleviated. Papillomavirus antigen A test was carried out, for each lesion to search human papillomavirus (HPV) antigen, using avidin-bioton peroxidase complex (ABC) method with monoclonal antibody against papillomavirus. The results obtained revealed that antigens were negative on all in the case with lichen sclerosus and in a hyperplastic dystrophy case not associated with atypia, but cases judged as being positive included 9 of 14 with atypia and 5 of 6 with carcinoma in situ.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Pathological and clinical observations on precancerous lesions of the vulva]. 301 6

On subcellular fractionation, carbonyl reductase (EC 1.1.1.184) activity in guinea pig lung was found in the mitochondrial, microsomal, and cytosolic fractions; the specific activity in the mitochondrial fraction was more than five times higher than those in the microsomal and cytosolic fractions. Further separation of the mitochondrial fraction on a sucrose gradient revealed that about half of the reductase activity is localized in mitochondria and one-third in a peroxidase-rich fraction. Although carbonyl reductase in both the mitochondrial and microsomal fractions was solubilized effectively by mixing with 1% Triton X-100 and 1 M KCl, the enzyme activity in the mitochondrial fraction was more highly enhanced by the solubilization than was that in the microsomal fraction. Carbonyl reductases were purified to homogeneity from the mitochondrial, microsomal, and cytosolic fractions. The three enzymes were almost identical in catalytic, structural, and immunological properties. Carbonyl reductase, synthesized in a rabbit reticulocyte lysate cell-free system, was apparently the same in molecular size as the subunit of the mature enzyme purified from cytosol. These results indicate that the same enzyme species is localized in the three different subcellular compartments of lung.
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PMID:Subcellular distribution and properties of carbonyl reductase in guinea pig lung. 304 13

The enzymes involved in antioxidative activity and the cellular content of the antioxidants glutathione and ascorbate in the cyanobacteria Nostoc muscorum 7119 and Synechococcus 6311 have been examined for their roles in hydroperoxide removal. High activities of ascorbate peroxidase and catalase were found in vegetative cells of both species and in the heterocysts of N. muscorum. The affinity of ascorbate peroxidase for H2O2 was 15- to 25-fold higher than that of catalase. Increased activity of ascorbate peroxidase was observed in N. muscorum when H2O2 production was enhanced by photorespiration. Catalase activity was decreased in dilute cultures whereas ascorbate peroxidase activity increased. Ascorbate peroxidase activity also increased when the CO2 concentration was reduced. Ascorbate peroxidase appears to be a key enzyme in a cascade of reactions regenerating antioxidants. Dehydroascorbate reductase was found to regenerate ascorbate, and glutathione reductase recycled glutathione. In vegetative cells glutathione was present in high amounts (2-4 mM) whereas the ascorbate content was almost 100-fold lower (20-100 microM). Glutathione peroxidase was not detected in either cyanobacterium. It is concluded from the high activity of ascorbate peroxidase activity and the levels of antioxidants found that this enzyme can effectively remove low concentrations of peroxides. Catalase may remove H2O2 produced under photooxidative conditions where the peroxide concentration is higher.
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PMID:Hydroperoxide metabolism in cyanobacteria. 308 78

Types 1 and 2C fibers in human skeletal muscle were cross-reactively identified with monoclonal anti-bovine neurofilament (200 kd) antibody. Thirty seven biopsy samples including sixteen vastus lateralis muscles, twelve lumbar paravertebral muscles, six gluteus medius muscles, two flexor carpi ulnaris muscles, and one flexor pollicis longus muscle, were examined. Serial transverse sections were stained histochemically with myofibrillar ATPase (pH 10.4, 4.6, 4.3) and DPNH-tetrazolium reductase reactions, and immunochemically using the avidin-biotin-peroxidase complex with the primary antibodies of monoclonal anti-bovine neurofilament (200 kd, 160 kd, 70 kd) antibodies and anti-bovine glial filament acidic protein antibody. The immunochemical reaction with anti-NF (200 kd) antibody could distinguish two kinds of fibers; positive and negative in all of the specimens. No fiber was recognized with other antibodies. Myosin ATPase reactions in serial sections proved that the positively stained fibers with anti-NF (200 kd) antibody were types 1 and 2C fibers and negative fibers types 2A and 2B fibers. At present, it is not known what substance is responsible for the cross-reaction with the monoclonal anti-NF (200 kd) antibody in types 1 and 2C fibers, but this unique antibody would be valuable in two aspects: one concerns the problem of the evolution of fiber types, and the other the utility as another supplemental method to conventional myosin ATPase scheme.
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PMID:Cross reactive identification of types 1 and 2C fibers in human skeletal muscles with monoclonal anti-neurofilament (200 kd) antibody. 311 44

In principle, target inactivation analysis provides a means of determining the molecular weights (Mr) and states of aggregation of proteins in native environments where they are functionally active. We applied this irradiation technique to the rat liver microsomal membrane proteins: cytochrome b5, epoxide hydrolase, flavin-containing monooxygenase, NADH-ferricyanide reductase, NADPH-cytochrome P-450 reductase, and seven different forms of cytochrome P-450. Catalytic activities, spectral analysis of prosthetic groups, and sodium dodecyl sulfate-polyacrylamide electrophoresis/peroxidase-coupled immunoblotting were used to estimate apparent Mr values in rat liver microsomal membranes. Except in one case (cytochrome P-450PCN-E), the estimated Mr corresponded most closely to that of a monomer. Purified cytochrome P-450PB-B, NADPH-cytochrome P-450 reductase and epoxide hydrolase were also subjected to target inactivation analysis, and the results also suggested monomeric structures for all three proteins under these conditions. However, previous hydrodynamic and gel-exclusion results clearly indicate that all three of these proteins are oligomeric under these conditions. The discrepancy between target inactivation Mr estimates and hydrodynamic results is attributed to a lack of energy transfer between monomeric units. Thus, while P-450PCN-E may be oligomeric in microsomal membranes, target inactivation analysis does not appear to give conclusive results regarding the states of aggregation of these microsomal proteins.
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PMID:Target inactivation analysis applied to determination of molecular weights of rat liver proteins in the purified state and in microsomal membranes. 311 94

The localization and distribution of NADPH-cytochrome P450 reductase and cytochrome P450C-M/F were investigated immunohistochemically in the liver and the kidney of untreated rats employing both an unlabelled antibody peroxidase-antiperoxidase method and a peroxidase labelled primary antibody technique. In both immunohistochemical procedures, the reductase and P450C-M/F were detected in hepatocytes throughout the liver. In contrast, the reductase and P450C-M/F in the kidney were only detectable in the proximal tubule cells.
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PMID:Immunochemical detection of cytochrome P450C-M/F and NADPH-cytochrome P450 reductase in rat liver and kidney. 312 46

An H2O2-generating fraction was prepared from porcine thyroid homogenate by differential and Percoll-density gradient centrifugations. The fraction consisted of mainly fragmented plasma membranes as judged by marker enzyme analysis and electron microscopy. The fraction produced H2O2 by reaction with NADPH only in the presence of Ca2+. The Ca2+ concentration for half-maximal activation (KCa) was about 0.1 microM and the Hill coefficient was 2. Sr2+ also activated the reaction whereas Mn2+, Zn2+, and Cd2+ inhibited it. The reaction was enhanced about twice by addition of ATP but not ADP, and inhibited by addition of hexokinase together with glucose to remove ATP. The Km value for NADPH was 35 microM and was less than 1/12 that for NADH. The NADPH oxidation rate was measured and the KCa and the Km were similar to those for the H2O2 production. The stoichiometry between the oxidation and the H2O2 formation was essentially 1. Superoxide dismutase (SOD) and KCN did not affect H2O2 production. The fraction catalyzed NADPH-cytochrome c reduction but the activity was SOD-insensitive. These results suggest that H2O2 was not generated through superoxide anion formation. NADPH-dichloroindophenol (DCIP) reductase activity was also observed and DCIP inhibited the production of H2O2. The cytochrome c and DCIP reductase activities were not influenced by Ca2+ or ATP. A unique electron transport system regulated by Ca2+ and ATP exists in the thyroid plasma membrane that produces H2O2. The concentrations of Ca2+ and ATP in thyroid cells may regulate hormone synthesis through activation of the production of H2O2, a substrate for peroxidase.
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PMID:Activation by ATP of calcium-dependent NADPH-oxidase generating hydrogen peroxide in thyroid plasma membranes. 312 60


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