Showing papers on "Glutathione published in 1972"
TL;DR: An apparent compensation mechanism is that with increased lipid peroxides there is increased activity of GSH peroxidase, which in turn increases lipid peroxide catabolism, and also function in the protective chain by providing increased levels of G SH and NADPH, respectively.
Abstract: The effects of whole animal exposure to ozone and of dietary α-tocopherol on the occurrence in rat lung of lipid peroxidation and alteration of the activity of enzymes important in detoxification of lipid peroxides were studied. Exposure to 0.7 and 0.8 ppm ozone continuously for 5 and 7 days, respectively, significantly elevated the concentration of TBA reactants, primarily malonaldehyde, produced by lipid peroxidation, as well as the activities of glutathione (GSH) peroxidase, GSH reductase and glucose-6-phosphate (G-6-P) dehydrogenase. As a logarithmic function of dietary α-tocopherol (0, 10.5, 45, 150 and 1500 mg/kg), the increase in formation of malonaldehyde and the increase in activities of GSH peroxidase and G-6-P dehydrogenase were partially inhibited. The activity of GSH reductase was not affected by dietary α-tocopherol. The concentration of malonaldehyde and the activity of GSH peroxidase in lung were linearly correlated (p<0.001). This study confirmed the occurrence of lipid peroxidation in the lung during ozone exposure and revealed an enzymatic mechanism against damage. An apparent compensation mechanism is that with increased lipid peroxides there is increased activity of GSH peroxidase, which in turn increases lipid peroxide catabolism. The increased activities of GSH reductase and G-6-P dehydrogenase also function in the protective chain by providing increased levels of GSH and NADPH, respectively.
321 citations
305 citations
TL;DR: A selective transition in the 2GSH/GSSG redox system is effected in intact liver cells by several organic hydroperoxides reported as active substrates for rat liver glutathione peroxidase.
243 citations
171 citations
TL;DR: Evidence suggests that a coupled monooxygenase-hydrase system, inducible by 3-methylcholanthrene, is present in liver microsomes and may convert aromatic compounds rapidly to dihydrodiols, thereby circumventing toxic effects of intermediate arene oxides.
153 citations
TL;DR: In some families with hemolytic anemia and a low level of reduced glutathione in erythrocytes, the disorder is associated with a deficiency of glutATHione synthetase, the second of two enz...
Abstract: In some families with hemolytic anemia and a low level of reduced glutathione in erythrocytes, the disorder is associated with a deficiency of glutathione synthetase, the second of two enz...
137 citations
TL;DR: The effect of the antibiotic, cycloheximide, on initiation of protein synthesis is interpreted in light of the GSSG effect, and a scheme for the behavior of Factor Q inprotein synthesis is proposed.
133 citations
TL;DR: It is concluded that GSH is the major target for diamide within the cell, and conversion of GSH to GSSG is the most important immediate consequence of diamide treatment of a cell suspension.
125 citations
TL;DR: Diamide is not absolutely specific for GSH in nucleated mammalian cells in Ehrlich ascites tumor cells, however.
83 citations
TL;DR: The data indicate that most or all of the insulin degrading activity observed under the experimental conditions used is due to the presence of glutathione-insulin transhydrogenase, which may be the major insulin-degrading activity present in the animal.
82 citations
Journal Article•
TL;DR: Exposure of rats or rat lung homogenates to 2 ppM O/sub 3/ reduced total, protein, and non-protein sulfhydryl fractions in a dose-related fashion and G6PD activity signals hexose-monophosphate shunt pathway for NADPH production.
TL;DR: Microsomal mixed-function oxidases in mouse liver liberate hydrogen cyanide from several organonitriles, probably as a result of hydroxylation at the α-methylene group to form an unstable cyanohydrin.
TL;DR: The adducts formed by the reaction between cysteine or glutathione with penicillic acid were identified and found to be non-toxic to mice, quails, and in the rabbit skin test but exhibited toxicity to the chick embryo.
Abstract: About 10% of 346 Penicillium cultures isolated from mold-fermented sausage synthesized the toxic metabolite penicillic acid on liquid media. Five of these producing cultures inoculated onto sausage failed to produce this toxin in up to 70 days of ripening. Several amino acids normally occurring in meat (cysteine, glutathione, arginine, histidine, and lysine) were found capable of readily reacting with penicillic acid. The adducts formed by the reaction between cysteine or glutathione with penicillic acid were identified and found to be non-toxic to mice, quails, and in the rabbit skin test but exhibited toxicity to the chick embryo. Hypotheses accounting for this residual toxicity are advanced.
TL;DR: DDC, penicillamine and sodium ethyldiaminetetraacetate in 1 mM concentrations significantly stabilized the membrane of isolated liver lysosomes, as shown by a decreased release of β-glucuronidase upon incubation at 37° and pH 5·0.
TL;DR: 4,4′-Diaminodiphenylsulfone (DDS) can produce methemoglobinemia in vivo, apparently by the action of an unidentified metabolic product, and DDS-NOH can be regenerated by reducing compounds to yield the high heme oxidation ratio.
TL;DR: Twenty-20 enzymatic activities and the glutathione content of newborn erythrocytes are compared to normal and to comparably reticulocyte-rich nonneonatal red cells to exhibit a characteristic metabolic pattern not explained by a young mean cell age alone.
Abstract: 20 enzymatic activities and the glutathione content of newborn erythrocytes are compared (a) to normal and (b) to comparably reticulocyte-rich nonneonatal red cells. Six were very high in comparison to either control group (GSH, PGK, Enol., G-3-PD, GPI, G-6-PD). Five were very low (ACHE, RPK, GSH-Px, AK and PFK). The mean of the remainder differed from the mean of comparably reticulocyte-rich blood by less than 1 SD of the latter mean. Cord erythrocytes exhibit a characteristic metabolic pattern not explained by a young mean cell age alone.
TL;DR: Human platelets were separated by desity-centrifugation into heavy and light populations and heavy platelets contained approximately twofold greater enzyme activity (per gram wet weight) than light platelets for 7 of the 16 enzymes measured.
Abstract: Human platelets were separated by desity-centrifugation into heavy and light populations. Heavy platelets have an average volume approximately twofold greater than light platelets, and have previously been shown to be young platelets.
All 11 enzymes of the Embden-Meyerhof pathway plus the five related enzymes: phosphoglucomutase, glucose-6-P dehydrogenase, 6-P-gluconic dehydrogenase, α-glycerol-P dehydrogenase, and glutathione reductase (TPNH) were examined in cell lysates from total, heavy, and light platelet populations. Apparent Km for individual enzymes were measured in a total platelet population. Empirical Vmax of the individual enzymes were measured in total, heavy, and light platelet populations. The three apparent rate-limiting enzymes for glycolysis were hexokinase, phosphofructokinase, and glyceraldehyde-3-P dehydrogenase.
Heavy platelets contained approximately twofold greater enzyme activity (per gram wet weight) than light platelets for 7 of the 16 enzymes measured: hexokinase, phosphohexoisomerase, phosphofructokinase, glyceraldehyde-3-P dehydrogenase, phosphoglycerokinase, lactic dehydrogenase, and phosphoglucomutase. Heavy platelets also contained 1.9-fold greater reduced glutathione (GSH), 1.7-fold greater DPNH, and 1.2-fold greater TPNH than light platelets. Heavy platelets contained 1.8-fold less lipid peroxidation products (malonyl aldehyde equivalents) than light platelets and were 2.4-fold more resistant to lipid peroxidation catalyzed by 0.1 mM FeCl3.
Sterile incubation of heavy platelets, in vitro for 17 hr, resulted in a significant loss of enzyme activity for the “elevated” seven enzymes when compared with the remainder. Reducing agents such as GSH (0.1 mM), ascorbic acid (0.1 mM), and dithiothreitol (0.01 mM), when added to the incubation mixture, significantly reduced the in vitro loss of activity. In vitro incubation was also associated with a significant loss of GSH and DPNH and a 1.8-fold increase in lipid peroxidation products.
TL;DR: The enzyme that catalyses this reaction is present in the soluble fraction of liver from mouse, rat, rabbit and pig at similar activity and it is likely that the enzyme plays an important role in the detoxification of the phosphate triester pesticides containing CH(3)-O-P groups.
Abstract: 1. 2-Chloro-1-(2,4,5-trichlorophenyl)vinyl dimethyl phosphate (tetrachlorvinphos) is demethylated by mammalian liver supernatant (100000g) protein in the presence of GSH. 2. GSH acts as an acceptor of the transferred methyl group to form S-methyl glutathione. 3. The enzyme that catalyses this reaction is present in the soluble fraction of liver from mouse, rat, rabbit and pig at similar activity. The enzyme was purified 45-fold from pig liver, dimethyl 1-naphthyl phosphate being used as assay substrate. 4. Methyl groups are readily removed from most of the substrates studied; ethyl groups are removed at one-fiftieth to one-hundredth of the rate for methyl groups. It is likely that the enzyme plays an important role in the detoxification of the phosphate triester pesticides containing CH3–O–P groups.
TL;DR: The resistant strain possessed higher activity for both the mixed-function oxidases and the glutathione transferase than the susceptible strain, and both systems appear to be important in the resistance mechanism.
TL;DR: Gliotoxin and two other compounds, with antiviral activity against a number of ribonucleic acid (RNA) viruses and structurally related via the epidithiapiperazinedione moiety, appeared to be equally active in their oxidized and reduced forms.
Abstract: Gliotoxin and two other compounds, with antiviral activity against a number of ribonucleic acid (RNA) viruses and structurally related via the epidithiapiperazinedione moiety, appeared to be equally active in their oxidized and reduced forms. However, the ability of the reduced forms to inhibit viral RNA synthesis was abolished when these compounds were maintained in the reduced state by the simultaneous presence of a large molar excess of dithiothreitol or reduced glutathione. The active form therefore appeared to be that containing a disulfide bridge, and the apparent activity of the dithiol was due to cellular oxidation. Possible mechanisms by which the compounds could interact with viral proteins, e.g., viral RNA-dependent RNA polymerase, are proposed.
TL;DR: The results indicate that the stimulatory effects of cysteine on white fat cell glucose utilization involve a mechanism dependent on the presence of divalent copper.
TL;DR: Several tissues in cockroach and rat were active in this conjugation, but the highest activity was found in the fat body and the liver, and the glutathione S -transferase catalyzing the conjugations was specific for glutathion, and could not be replaced by other SH compounds.
TL;DR: Six patients with documented defects in platelet function were screened for possible abnormalities in platelets energy metabolism and reductive capacity and abnormalities found in the reductiv...
Abstract: Six patients with documented defects in platelet function were screened for possible abnormalities in platelet energy metabolism and reductive capacity. Abnormalities found in the reductiv...
TL;DR: The enzyme which catalyzes the transfer of the triazinyl group from the 2-chlorotriazine to glutathione is located in the liver cytosol and some of the properties of this glutATHione transferase have been investigated.
TL;DR: Notable differences between glyoxalase I from yeast and from porcine erythrocytes appear in molecular weight, kinetics, and reactivation of chelator-inhibited enzyme.
Abstract: Glyoxalase I from porcine erythrocytes has been purified about 2000-fold by ion-exchange chromatography on SE-Sephadex, CM-cellulose and DEAE-cellulose columns. The isoelectric point was estimated to be at about pH 5, and the molecular weight was 52000 as determined by gel filtration. The kinetics of the enzymatic reaction was studied and the Km value was determined to be 0.19 mM, which differs significantly from the Km value of the yeast glyoxalase I. The enzymatic activity is completely inhibited by the chelating agents EDTA and o-phenanthroline, and activity is regained by addition of Mg2+, Mn2+, and Ca2+. The reactivation is time-dependent, which indicates that a metal · enzyme complex is the catalytically active species. An apparent dissociation constant of 0.6 mM for the Mg2+· enzyme complex was determined.
Notable differences between glyoxalase I from yeast and from porcine erythrocytes appear in molecular weight, kinetics, and reactivation of chelator-inhibited enzyme.
TL;DR: It is concluded that GSH is released from proteins by cysteamine treatment in an exchange reaction, suggesting that protein-bound GSH may be regarded as a reservoir of a radioprotective substance which can be released under certain conditions and, when released, can contribute to enhance the radioresistance of cells.
Abstract: SummaryThe non-protein-bound part of cellular mixed disulphides between proteins and thiols was analysed by gel-filtration after reduction of the disulphide bonds. Glutathione (GSH) was found to be the only detectable low-molecular thiol bound to cellular proteins. Reduction of disulphide bonds resulted, in addition to the release of GSH, in the liberation of sulphydryl-containing protein fragments of various sizes.Using cells in which the sulphur was labelled with 35S, it was demonstrated that about 15 per cent of the incorporated cysteamine was bound to the proteins, and that GSH was released in comparable amounts. The protein-cysteamine bound was stable for at least 95 min.It is concluded that GSH is released from proteins by cysteamine treatment in an exchange reaction. The data suggest, furthermore, that protein-bound GSH may be regarded as a reservoir of a radioprotective substance which can be released under certain conditions and, when released, can contribute to enhance the radioresistance of cells.
TL;DR: Reduced glutathione (GSH) levels of erythrocytes were determined in five sheep breeds and the Merino breed had a higher incidence of low GSH animals than the other breeds tested.
Abstract: Reduced glutathione (GSH) levels of erythrocytes were determined in five sheep breeds. The Merino breed had a higher incidence of low GSH animals than the other breeds tested. High GSH type animals of the Border Leicester breed had a significantly lower mean GSH level than did higher GSH animals of the other breeds.
TL;DR: Two methods for the determination of glutathione peroxidase (GSH‐Px) activity have been compared and the overall superiority of a linked‐enzyme system has been confirmed.
Abstract: Summary
Two methods for the determination of glutathione peroxidase (GSH-Px) activity have been compared and the overall superiority of a linked-enzyme system has been confirmed. The erythrocyte GSH-Px activity was measured in 120 newborn infants and compared with older children and adults. A definite deficiency of the enzyme was found in the former group, but could not be related to evidence of haemolysis. A relationship between serum tocopherol levels and erythrocyte GSH-Px was found and the possible implications are discussed.
TL;DR: Red cells from Finnish Landrace sheep with an inherited deficiency of reduced glutathione were found to contain high concentrations of ornithine and lysine, in contrast to red cells from normal individuals.