Disease relevance of GPX1

• However, the low levels of glutathione peroxidase resulting from selenium deficiency cause an increase susceptibility to peroxide-mediated toxicity [1].
• The activities of GSHPx and the vitamin E levels in plasma were not significantly different in the two groups of herds, and no relationship was found between the two nutrients and the incidence of clinical mastitis [2].
• No differences occurred between immunization groups in blood selenium and glutathione peroxidase activity, plasma selenium, number of E. coli 727 isolated from secretion after challenge, rectal temperature and SCC response, clinical status of mammary quarters, or DMI [3].
• Selenium effects on glutathione peroxidase and the immune response of stressed calves challenged with Pasteurella hemolytica [4].
• No significant differences in body weight, plasma concentrations of urea, or whole blood concentrations of glutathione peroxidase were detected between groups before or after calving [5].

Psychiatry related information on GPX1

• It was concluded that selenium supplementation in cows with low GPx activity seems to support udder defense mechanisms that favor reduction of the incidence of new mastitis cases [6].

High impact information on GPX1

• In this study, we tested the hypothesis that overexpression of GPx-1 can restore the normal endothelial phenotype in hyperhomocyst(e)inemic states [7].
• An elevated level of homocysteine in vivo and in cell culture systems results in a decrease in the activity of cellular glutathione peroxidase (GPx1), an intracellular antioxidant enzyme that reduces hydrogen peroxide and lipid peroxides [8].
• These data support the conclusion that homocysteine decreases GPx1 activity by altering the translational mechanism essential for the synthesis of this selenocysteine-containing protein [8].
• Expression of the selenocysteine (SEC)-containing GPx1 protein requires special translational cofactors to "read-through" a UGA-stop codon that specifies SEC incorporation at the active site of the enzyme [8].
• We investigated the anti-apoptotic effects of intracellular and extracellular nitric oxide (*NO) donors, iron chelators, cell-permeable superoxide dismutase (SOD), glutathione peroxidase mimetics, and nitrone spin traps [9].

Chemical compound and disease context of GPX1

• Weight gains for the 21-d study were not affected by Se status, although whole blood and plasma glutathione peroxidase (GSH-Px) were higher (P less than .05) for +Se calves [4].
• The glutathione oxidant defence system in leucocytes and erythrocytes of six Anaplasma marginale-infected calves was examined by assaying glutathione peroxidase (GSH-px), glutathione reductase (GSSG-R), reduced glutathione (GSH) and superoxide dismutase (SOD) [10].
• AIMS: To investigate the activity response of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) of the rumen bacterium Streptococcus bovis following exposure to mercury(II) chloride (HgCl(2) in the presence of plant antioxidants [11].
• Studies on serum tocopherol, selenium levels and blood glutathione peroxidase activities in calves with white muscle disease [12].
• The effect of buparvaquone treatment on the levels of some antioxidant vitamins, lipid peroxidation and glutathione peroxidase in cattle with theileriosis [13].

Biological context of GPX1

• The amino-acid sequence of bovine glutathione peroxidase [14].
• In view of the physiological importance of adrenocortical lipid peroxidation, we have carried out subcellular fractionation to determine the location of glutathione peroxidase, an enzyme which protects against lipid peroxidation [15].
• Selenium (Se) is an integral part of the Se-dependent glutathione peroxidase (Se-GSH-Px) catalytic domain [16].
• Upregulation of GSH-Px and depletion of GSH indicate a reparative process of accelerated elimination of reactive oxygen species following rapid glucose reduction [17].
• Typical demands for NADPH may be to detoxify H2O2 and/or organic peroxides through the glutathione peroxidase/glutathione reductase system, and both generating and removing products of the "killing reaction" during phagocytosis [18].

Anatomical context of GPX1

• The amino-acid sequence of the seleno-enzyme glutathione peroxidase from bovine erythrocytes was completely determined [14].
• To test this hypothesis, confluent bovine aortic endothelial cells were treated with a range of concentrations of Hcy, and intracellular GPx activity was determined [19].
• Cells cultured on a plastic substrate had substantially less glutathione peroxidase activity than cells cultured on either BCE or HR-9 basement membranes [20].
• Glutathione peroxidase of calf trabecular meshwork [21].
• In the present experiments, the lack of significant bioavailable amounts of selenium in the medium was demonstrated by the finding of only low levels of glutathione peroxidase in the cultured cells (0.008 U/mg protein compared with 0.045 U/mg protein in fresh adrenocortical tissue) [1].

Associations of GPX1 with chemical compounds

• Low levels of phenol (which is normally stimulatory) or alpha-naphthol when combined with NaCN or glutathione peroxidase (agents which interfere with peroxide activation) resulted in potent synergistic inhibition with long lag times [22].
• PDGF stimulated a substantial increase in intracellular reactive oxygen species, as measured by the fluorescence of dichlorofluorescein-loaded cells, and this was blocked by the glutathione peroxidase mimetic ebselen [23].
• Homocyst(e)ine-dependent lipid peroxidation is independent of H(2)O(2) and alterations in glutathione peroxidase activity, but dependent on superoxide [24].
• Selenium (Se) is an integral component of glutathione peroxidase and is able to detoxify peroxides that can affect arachidonic acid (AA) metabolism, thereby influencing eicosanoid biosynthesis [25].
• Oxidation of the active center cysteine of BRPrx by H2O2 proceeded only several times slowly than that of the selenocysteine of glutathione peroxidase [26].

Physical interactions of GPX1

• Glutathione peroxidase (GSH-Px) activity was evaluated in a coupled test system using NADPH/GSSG reductase as an indicator and cyclooxygenase activity was evaluated using sheep seminal vesicle prostaglandin synthase [27].

Regulatory relationships of GPX1

• This effect is independent of its GSH-Px activity and its ability to inhibit cyclooxygenase and PGE2 production [27].

Other interactions of GPX1

• Using in situ hybridization, we demonstrated that GPx-4 expression is almost restricted to the oviductal luminal epithelium in contrast to GPx-1, which is widely distributed, and GPx-2 and -3, which are mainly detected in the epithelial cells and lamina propria [28].
• Marked increases in the activities of GSH-Px, SOD and G6PD from the pretrial values were observed upon initial feeding of basal concentrate diet [29].
• Endothelial cells produce H2O2 at an intracellular site in the vicinity of peroxisomes and at a second site near the cell surface that is inaccessible to intracellular catalase or glutathione peroxidase [30].
• The high levels of expression for GPx-3 in the isthmus were in contrast to expression of GPx-1 and GPx-2, which occurred mostly in the ampulla and infundibulum of the oviduct [31].
• Purification studies isolated two forms of glutathione reductase [GR I (140 kDa) with subunit Mr of 70 kDa and GR II (greater than 670 kDa) with subunit Mr of 45 kDa] and a novel glutathione peroxidase (112 kDa with subunit Mr of 29 kDa) [32].

Analytical, diagnostic and therapeutic context of GPX1

• The clear zone of GSH-Px activity on a purple background was found in both native and SDS-PAGE gels [33].
• The total glutathione peroxidase activity fractionated with the transferases in the gel-filtration range of mol.wt [34].
• The antibody also cross-reacted with the subunits of Chlamydomonas glutathione peroxidase in Western blotting SDS/PAGE [35].
• On immunoprecipitation, Chlamydomonas glutathione peroxidase was precipitated and its activity was inhibited about 90% by the antibody raised against bovine erythrocyte glutathione peroxidase [35].
• GSH-Px activity was statistically significantly higher in fetal than in maternal placenta in all examined groups, increased towards parturition and was higher in caesarean section groups than spontaneous delivery groups [36].

References