scholarly journals The transport of oxidized glutathione from the erythrocytes of various species in the prescence of chromate

1969 ◽  
Vol 114 (4) ◽  
pp. 833-837 ◽  
Author(s):  
Satish K. Srivastava ◽  
Ernest Beutler
Keyword(s):  
Hydrogen Peroxide ◽  
Glutathione Reductase ◽  
Pyruvate Kinase ◽  
Transport Rate ◽  
Oxidized Glutathione ◽  
Phosphogluconate Dehydrogenase ◽  
Presence And Absence ◽  
Glucose 6 Phosphate Dehydrogenase

1. Erythrocytes from normal and glucose 6-phosphate dehydrogenase-deficient humans were subjected to hydrogen peroxide diffusion to oxidize the GSH. Studies were carried out in the presence and absence of chromate to inhibit glutathione reductase and with or without the addition of glucose. 2. The GSH content of erythrocytes from other species was oxidized by subjecting them to hydrogen peroxide diffusion in the presence of chromate and glucose. 3. Chromate (1·3mm) inhibited glutathione reductase by about 80%, whereas glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, hexokinase, phosphofructokinase and pyruvate kinase were not inhibited. 4. The GSSG formed was transported from the erythrocytes to the medium. 5. The transport rate of GSSG from glucose 6-phosphate dehydrogenase-deficient erythrocytes subjected to hydrogen peroxide diffusion in the presence of chromate was comparable with that from normal and glucose 6-phosphate dehydrogenase-deficient erythrocytes. 6. The rate of transport of GSSG from erythrocytes of various species studied could be ranked: pigeon>rabbit>rat>donkey>man>dog>horse>sheep>chicken>fish.

scholarly journals Depletion of glycogen synthetase and increase of glucose 6-phosphate dehydrogenase in livers of ethionine-treated mice

1965 ◽  
Vol 97 (1) ◽  
pp. 32-36 ◽  
Author(s):  
HG Sie ◽  
A Hablanian
Keyword(s):  
Pyruvate Kinase ◽  
Glucose Dehydrogenase ◽  
Liver Glycogen ◽  
Synthetase Activity ◽  
Phosphogluconate Dehydrogenase ◽  
Glycogen Synthetase ◽  
Glucose 6 Phosphate Dehydrogenase

1. Ethionine-treated mice showed a marked depletion in liver glycogen, a decrease of glycogen-synthetase activity, an increase in activity of glucose 6-phosphate dehydrogenase and the solubilization of phosphorylase. 2. The administration of cortisol or glucose did not alleviate these changes but the effect of ethionine was completely prevented in animals given methionine as well as ethionine. 3. The activities of the following enzymes were unchanged: hexokinase, glucokinase, glucose 6-phosphatase, phosphoglucomutase, 6-phosphogluconate dehydrogenase, UDP-glucose pyrophosphorylase, UDP-glucose dehydrogenase and pyruvate kinase.

scholarly journals Degradation of glucose-metabolizing enzymes in the rat small intestine during starvation

1973 ◽  
Vol 132 (4) ◽  
pp. 657-661 ◽  
Author(s):  
Gwyneth M. Jones ◽  
R. J. Mayer
Keyword(s):  
Small Intestine ◽  
Lactate Dehydrogenase ◽  
Pyruvate Kinase ◽  
Phosphoglycerate Kinase ◽  
Rat Small Intestine ◽  
Metabolizing Enzymes ◽  
Phosphogluconate Dehydrogenase ◽  
Degradation Rates ◽  
Glucose 6 Phosphate Dehydrogenase

1. The degradation rates and half-lives of hexokinase, 6-phosphogluconate dehydrogenase, lactate dehydrogenase, pyruvate kinase, glucose 6-phosphate dehydrogenase, phosphoglycerate kinase and aldolase were calculated from measurements of the decline in activities of these enzymes in rat small intestine during starvation. 2. The half-lives of the enzymes are: hexokinase, 5.7h; 6-phosphogluconate dehydrogenase, 7.6h; glucose 6-phosphate dehydrogenase, 6.0h; pyruvate kinase, 8.9h; lactate dehydrogenase, 8.7h; phosphoglycerate kinase, 8.7h; aldolase, 5.1h. 3. The significance of the results is discussed with respect to the regulation of enzyme concentrations in response to changes in diet.

scholarly journals A critical appraisal of the effect of oxidized glutathione on hepatic glucose 6-phosphate dehydrogenase activity

1983 ◽  
Vol 214 (3) ◽  
pp. 959-965 ◽  
Author(s):  
H R Levy ◽  
M Christoff
Keyword(s):  
Glutathione Reductase ◽  
Dehydrogenase Activity ◽  
Rat Liver ◽  
Critical Appraisal ◽  
Oxidized Glutathione ◽  
Assay Procedure ◽  
Low Concentrations ◽  
Hepatic Glucose ◽  
Spurious Effect ◽  
Glucose 6 Phosphate Dehydrogenase

Experiments were undertaken to elucidate the mechanism of the reversal of NADPH inhibition of rat liver glucose 6-phosphate dehydrogenase by oxidized gluthathione alone and in combination with a putative cofactor described by Eggleston & Krebs [(1974) Biochem. J. 138, 425-435]. Evidence is presented that this reversal is largely an artifact, caused by the incorrect application of a control assay procedure and a spurious effect of Zn2+ (added in order to inhibit glutathione reductase) in crude enzyme solutions. When the proper assay procedure is used and glutathione reductase is inhibited with low concentrations of Hg2+, glutathione addition has no effect on NADPH inhibition of glucose 6-phosphate dehydrogenase. No evidence was found for the existence of a cofactor that mediates an effect of glutathione on glucose 6-phosphate dehydrogenase.

Sign in / Sign up

Export Citation Format

Share Document