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Query: KEGG:D02003 (NBT)
 1,323 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using the direct method of pulse radiolysis to determine the superoxide dismutase like activity of copper(II) cimetidine complexes, it was found that the reaction rate constant with O2-, kcat, was (8.5 +/- 0.5) x 10(8) M-1s-1 independent of the cimetidine concentrations present in excess of 50-200 microM over the metal. The results suggest that either the 1:1 ligand to metal complex does not catalyze O2- dismutation at a comparable rate to that of the 2:1 complex, or that the stability constant of the last species is much higher than that determined earlier by Kimura et al., and only the 2:1 species is present in the solutions. With the indirect methods of cytochrome c and NBT for determining the ability of these complexes to catalyze O2 dismutation, these compounds exhibited a much lower SOD activity, and kcat was determined to be (5.0 +/- 0.3) x 10(6) and (7.6 +/- 0.4) x 10(7) M-1s-1, respectively using the two assays.
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PMID:Determination of the superoxide dismutase-like activity of cimetidine-Cu(II) complexes. 164 90

The experiment was carried out on 50 slaughter cocks, aged 5 weeks. The purpose of the experiment was to estimate the effect of beta-carotene and apo-beta-carotenoic acid (10% Carophyll yellow) on some indices of cellular immunity in chicks receiving the feed of high vitamin A content. Chl and NBT proved that carotenoids increased phagocytic activity of neutrophiles in peripheral blood. Similarly, in the case of beta-carotene it was found by blastic transformation test that on 30-40th day of the experiment, the value IS of peripheral blood lymphocytes was increased. On the other hand, chicks fed apo-beta-carotenoic acid showed such an effect on 40th day of observation only in the case when the lowest dose of preparation (24 mg/kg of feed) and Con A as mitogen were applied. In each experimental group, the chicks exhibited increased flavin content in liver and markedly increased retinol content due to apo-beta-carotenoic acid (24 mg/kg of feed). On the other hand, the contents of alpha tocopherol and ascorbic acid did not show significant differences between experimental and control groups. Similar were the results with iron, zinc and magnesium. Copper content of the liver was markedly increased in the birds receiving apo-beta-carotenoic acid in the dose of 24 mg/kg of feed. The increased content of manganese was observed in the liver of birds receiving beta carotene (6 mg/kg of feed).
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PMID:[Effect of carotenoids on selected indicators of cellular immunity in cockerels receiving food with high level of vitamin A]. 213 44

A superoxide dismutase (SOD) activity in saliva and gastric juice has been revealed using the NBT reduction and adrenaline autooxidation assays. This activity in saliva is induced mainly by enzymic mechanisms, whereas in gastric juice--by nonenzymic mechanisms. The gel chromatographic analysis of saliva has demonstrated the presence of several SOD isoenzymes. Nonenzymic mechanisms of the SOD activity in gastric juice involve the ionic activity of H+, Cu2+ and that of reduced glutathione. The SOD activity in gastric juice can be decreased by adding antacids and Fe ions. The effect of Fe3+ is found to be different depending on the methods of the SOD activity evaluation. Such metal-chelating agents as histidine and organic acids increase the SOD activity in gastric juice.
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PMID:[Superoxide dismutase activity of digestive secretions]. 236 86

Metallothionein inhibited in a concentration-dependent fashion the reduction of nitroblue tetrazolium [NBT] mediated by xanthine oxidase and by NADH-phenazine methosulfate. This catalytic activity of metallothionein for dismutation of O2- is dependent on the copper content in metallothionein.
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PMID:Inhibition of nitroblue tetrazolium reduction by metallothionein. 689 6

The investigations were done on 12 calves (age: 3 to 8 weeks). Six calves received (with an interval of two weeks) two intramuscular injections, each of which contained 5.75 mg selenium and 75 mg alpha-tokopherolacetate (Ursoselevit). Subsequently, they showed higher blood leukocyte counts (with less variation; p < 0.05), a greater phagocytosis index and more NBT-positive granulocytes than six untreated controls. Furthermore, their sera contained more carotenes, vitamin A and gamma-globulines than those of the controls. The other parameters considered within this trial (i.e. erythrocyte count, hemoglobin concentration, hematocrit, serum contents of calcium, magnesium, sodium, potassium, copper, iron and zinc) did not show statistically valuable differences between the members of the two groups.
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PMID:[Effect of selenium and vitamin E on white cells, serum concentration of several minerals and trace elements as well as immunologic parameters in calves]. 908 18

Only small amounts of superoxide dismutase (SOD) are present in the extracellular space to scavenge excess amounts of superoxide anions (02-) released after traumatic brain injury (TBI). Experiments were performed in rats with cerebral contusion produced by weight-drop technique. We investigated the effects of exogenous lecithinized SOD (PC-SOD) on accumulation of 02- produced in our model, by measuring the level of SOD activity (using the NBT-reducing method) and the expression of copper, zinc-SOD (Cu, Zn-SOD) mRNA (by Northern blot analysis). As determined by tissue-specific gravity, administration of PC-SOD reduced brain edema in the periphery of the lesion 6 h after contusion. SOD activity increased in the peripheral region at 30 min after contusion, but returned to normal levels at 6 h after TBI. Administration of PC-SOD increased SOD activity up to 6 h after TBI. The expression of Cu, Zn-SOD mRNA increased in the core region, peripheral portion, and contralateral hemisphere up to 6 h after TBI, then was suppressed in all three regions by PC-SOD. Our results confirm the important role of 02- in the development of brain edema after TBI and indicate that PC-SOD diminishes brain edema through a protective effect against 02-.
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PMID:Effects of lecithinized superoxide dismutase on traumatic brain injury in rats. 938 92

The tetrapeptide-Cu(II) complex H-(l-His-Gly)2-OH/Cu(II), indicated as L-Cu(II), has been investigated, as compared to the Cu(II) inorganic salt CuSO4, for its antioxidative and anti-inflammatory properties under a panel of experimental conditions. Both inorganic and organic Cu(II) compounds showed comparable activities in vitro and ex vivo by: (i) protecting, in a dose-dependent manner, rat brain homogenates from Fe(III)/ascorbate- or haemoglobin-induced lipid peroxidation; (ii) inhibiting the superoxide-mediated ferricytochrome c reduction by activated macrophages. CuSO4 and L-Cu(II) also exhibited similar anti-inflammatory effects in vivo by reducing significantly the extent of carrageenan-induced edema in the rat paw. The activities of the two compounds diverged strikingly only in the xanthine/xanthine oxidase system at low phosphate buffer concentration. L-Cu(II) decreased the rate of NBT reduction by superoxide in a true SOD-like fashion without affecting urate production. Instead, Cu(II) ions caused the rapid xanthine oxidase inactivation thus inhibiting both urate and superoxide production; this effect might be ascribed to the superoxide-mediated generation of the strong oxidant Cu(III) and its interaction with the enzyme. The administration of Cu(II), whether complexed with linear oligopeptides or as an inorganic salt, to animals or tissue extracts, conferred protection against oxidation and ought, conceivably, to interact with endogenous biological molecules and form highly bioavailable complexes which serve, subsequently, as the real scavengers. Moreover, the claimed prominent scavenger activities of Cu(II)-oligopeptide complexes over inorganic copper ions could be realised only in very simple in vitro systems through mechanisms which, although of biochemical interest, are unlikely to be of physiopathological significance.
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PMID:An in vivo, ex vivo and in vitro comparative study of activity of copper oligopeptide complexes vs Cu(II) ions. 977 91

Children with phenylketonuria (PKU) are treated with semisynthetic diets restricted in phenylalanine (PHE). The formulae must supply those trace elements and vitamins that are usually supplied by whole protein foods. We studied the effects of phenylalaline restricted diets in 42 children with PKU (P) and 31 normal (N) children, aged 1-12 y, divided into two groups (below and above 7 y). Plasma zinc and copper were analyzed by means of atomic spectrophotometry, and superoxide dismutase (CuZnSOD) activity was measured in erythrocytes, through NBT inhibition and its profile, as determined by isoelectric focalization. Plasma zinc of PKU children > or = 7 years old was significantly lower than that in the control group (17 mumol/L versus 20 mumol/L) but still within the normal range; in children < 7 years no substantial differences were found between the two groups. Plasma copper was not statistically different between PKU and normal children. Qualitative activity of CuZnSOD presented the same electrophoretic profile in both normal and PKU. Quantitative activity was not different in both P (1210 U/g Hb < 7 versus 1328 U/g hemoglobin (Hb) > or = 7) and N (1675 U/g Hb < 7 versus 1367 U/g Hb > or = 7). We concluded that children with PKU presented normal mean levels of zinc and copper, with preserved function, measured by enzyme activity.
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PMID:Plasma zinc, copper, and erythrocyte superoxide dismutase in children with phenylketonuria. 1037 99

The effects of cimetidine, a potent histamine-H2-receptor antagonist and a good -OH scavenger, on the kinetics of ferricytochrome c and NBT reduction by superoxide anions were studied. The drug dose-dependently inhibited ferricytochrome c and NBT reduction by O2- radicals, generated either in xanthine oxidase system or photochemically or directly by KO2. The inhibitory effect of cimetidine remained unchanged in the presence of catalase or mannitol. Cimetidine and its complexes with Cu(II) and Fe(III) ions inhibited ferricytochrome c and NBT reduction even when metal chelators were added to the reaction medium. The results suggest the reaction of cimetidine with O2-radicals.
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PMID:Effects of cimetidine and its metal complexes on nitroblue tetrazolium and ferricytochrome c reduction by superoxide radicals. 1048 Jun 60

A direct and rapid SDS-PAGE staining method for in situ identification of activity and molecular weight of superoxide dismutase following denaturing treatment has been developed. This technique was based on the removal of SDS after SDS-PAGE and two-step staining procedures of the SDS-polyacrylamide gel to present the achromatic activity-zones of the enzymes. We demonstrated that the detection sensitivity of SDS-PAGE staining method was the same as the traditional xanthine oxidase-NBT solution assay. Through the SDS-PAGE staining method, three classes of superoxide dismutases with distinct molecular sizes were identified in situ. Moreover, activity of copper and zinc containing superoxide dismutase in crude extracts of Escherichia coli and Actinobacillus pleuropneumoniae was significantly enhanced using the two-step staining procedure.
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PMID:A simple technique for the simultaneous determination of molecular weight and activity of superoxide dismutase using SDS-PAGE. 1124 94


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