Search results for "GPX3"
showing 9 items of 9 documents
Correlation between superoxide dismutase, glutathione peroxidase and catalase in isolated rat hepatocytes during fetal development
1981
Abstract Superoxide dismutase, glutathione peroxidase and catalase activities were determined in isolated fetal rat hepatocytes of various ages and compared with the values of neonatal and adult cells. The developmental pattern of superoxide dismutase and glutathione peroxidase were very similar with a low constant activity in the fetal cells and a postnatal burst. On the contrary catalase begins to increase already since the 18th day of the fetal life. The results suggest a functional correlation of superoxide dismutase and glutathione peroxidase in the antioxidative enzyme defense of liver cells.
Physiological changes in glutathione metabolism in foetal and newborn rat liver
1991
Glutathione metabolism was studied in isolated hepatocytes from foetal, newborn and adult rats. The GSH/GSSG ratio decreased 15-20-fold through the foetal-neonatal-adult transition. This was mainly due to an increase in GSSG. All enzyme activities involved in the glutathione redox cycle tend to increase during that transition, but the relative increases in glutathione peroxidase and glutathione S-transferase were 3-5 times those of glutathione reductase or glucose-6-phosphate dehydrogenase. GSH synthesis from methionine as a sulphur source was 6 times lower in foetal than in adult hepatocytes. However, when N-acetylcysteine was used as a sulphur donor to by-pass the cystathionine pathway, t…
Glutathione metabolism in skeletal muscle derived cells of the L6 line
1993
Skeletal muscle derived L6 myoblasts possess a considerably high resting total glutathione (TGSH) pool. Exposure to L-buthionine-[S,R]-sulphoximine resulted in a 90% depletion of the intracellular TGSH pool. All the key enzymes of glutathione metabolism, especially glutathione S-transferase, were observed to be considerably active in the undifferentiated cells. Se-dependent glutathione peroxidase activity appeared to account for most of the total GSH peroxidase activity of the cells. A significant contribution of gamma-glutamyl transpeptidase-independent (5 mM acivicin insensitive) mechanism to the extracellular GSH uptake capacity of the muscle cells was evident. Efflux of oxidized glutath…
Antioxidant and glutathione-related enzymatic activities in rat sciatic nerve
1990
Abstract The present work tries to establish the antioxidant capacity of the peripheral nervous tissue of the rat, in terms of the enzymatic activities present in this tissue that either prevent the formation of activated species as the semiquinone radical (DT-diaphorase), protect against activated oxygen species (superoxide dismutase, glutathione peroxidase), conjugate natural toxic products or xenobiotics (glutathione S-transferases, especially the activity conjugating 4-hydroxy-nonenal), or complete the glutathione system metabolism (glutathione disulfide reductase, γ-glutamyl transpeptidase). All the activities studied are lower in this tissue than they are in liver, except for γ-glutam…
Gene expression profile induced by ovariectomy in bone marrow of mice: a functional approach to identify new candidate genes associated to osteoporos…
2013
Osteoporosis is a multifactorial skeletal pathology with a main genetic component. To date, however, the majority of genes associated with this pathology remain unknown since genes cataloged to date only explain a part of the heritability of bone phenotypes. In the present study, we have used a genome-wide gene expression approach by means of microarrays to identify new candidate genes involved in the physiopathology of osteoporosis, using as a model the ovariectomized (OVX) mice by comparing global bone marrow gene expression of the OVX mice with those of SHAM operated mice. One hundred and eighty transcripts were found to be differentially expressed between groups. The analysis showed 23 …
Glutathione metabolism under the influence of hydroperoxides in the lactating mammary gland of the rat. Effect of glucose and extracellular ATP.
1987
Tert-butyl hydroperoxide decreases GSH and total free glutathione (GSH+2GSSG) contents of acini from lactating mammary glands. The decrease in total free glutathione can be explained by an increase in mixed disulfide formation and by excretion of GSS G to the extracellular medium, and subsequent degradation catalyzed by gamma-glutamyl transpeptidase. Low concentrations of glucose prevented the changes in glutathione levels induced by the peroxide. In the presence of extracellular ATP, glucose did not prevent these changes. However, incubations with the peroxide, did not alter the rate of other metabolic pathways by acini.
The distribution, induction and isoenzyme profile of glutathione S-transferase and glutathione peroxidase in isolated rat liver parenchymal, Kupffer …
1989
The distribution and inducibility of cytosolic glutathione S-transferase (EC 2.5.1.18) and glutathione peroxidase (EC 1.11.1.19) activities in rat liver parenchymal, Kupffer and endothelial cells were studied. In untreated rats glutathione S-transferase activity with 1-chloro-2,4-dinitrobenzene and 4-hydroxynon-2-trans-enal as substrates was 1.7-2.2-fold higher in parenchymal cells than in Kupffer and endothelial cells, whereas total, selenium-dependent and non-selenium-dependent glutathione peroxidase activities were similar in all three cell types. Glutathione S-transferase isoenzymes in parenchymal and non-parenchymal cells isolated from untreated rats were separated by chromatofocusing …
Control of the ribulose 1,5-bisphosphate carboxylase/oxygenase activity by the chloroplastic glutathione pool.
2014
The CO2-fixing activity of ribulose 1,5-bisphosphate carboxylase/oxygenase depends on the redox state of its cysteines. Disulfides like cystamine or 5,5'-dithio-bis(2-nitrobenzoic acid), but not oxidized glutathione, switch the enzyme to the inactive oxidized form. Conversely, thiols like cysteamine, cysteine, dithiotreitol or 2-mercaptoethanol, but not reduced glutathione, recover enzymatic activity after a previous oxidation. Direct regulation of the carboxylase activity by the chloroplastic glutathione pool is hindered by kinetic barriers impeding access to the critical residues. However, reduced glutathione can drive the recovery of activity by means of minute amounts of smaller interme…
4-hydroxynonenal inhibits glutathione peroxidase: protection by glutathione
1999
Abstract 4-Hydroxy-2,3-trans-nonenal, a lipid peroxidation product, inhibits glutathione peroxidase in a concentration-dependent manner. The concentration providing 50% inhibition is 0.12 mM. This inhibition can be almost completely (89%) prevented by 1 mM glutathione added to the incubation mixture 30 min before 4-hydroxy-2,3-trans-nonenal or 2,3-trans-nonenal, but not by other thiol-containing antioxidants such as 0.5 mM dithiothreitol or β-mercaptoethanol. Again the addition of 1 mM glutathione, and not of 0.5 mM dithiothreitol or β-mercaptoethanol, to the enzyme 30 min after incubation with 4-hydroxy-2,3-trans-nonenal restores activity to the same extent as does the preincubation with G…