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.

Purification and Kinetic Properties of 6-Phosphogluconate Dehydrogenase from Rat Small Intestine

2005 ◽  
Vol 24 (5) ◽  
pp. 293-301 ◽  
Author(s):  
Deniz Ceyhan ◽  
Ali Danişan ◽  
I. Hamdi Öğüş ◽  
Nazmi Özer
Keyword(s):  
Small Intestine ◽  
Kinetic Properties ◽  
Rat Small Intestine ◽  
Phosphogluconate Dehydrogenase

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.

Factors Affecting the Release of Haemoglobin and Enzymes from Human Erythrocytes

1975 ◽  
Vol 12 (1-6) ◽  
pp. 58-65 ◽  
Author(s):  
J. H. Wilkinson ◽  
Jean M. Robinson ◽  
K. P. Johnson
Keyword(s):  
Lactate Dehydrogenase ◽  
Phospholipase C ◽  
Pyruvate Kinase ◽  
Energy Content ◽  
Protective Action ◽  
Creatine Phosphate ◽  
Human Erythrocytes ◽  
Prolonged Incubation ◽  
Factors Affecting ◽  
Glucose 6 Phosphate Dehydrogenase

The efflux of lactate dehydrogenase and haemoglobin from human erythrocytes during prolonged incubation at 37° was significantly reduced by ATP, ADP, AMP, UTP, creatine phosphate, or phosphoenolpyruvate and to a lesser extent by fructose, glucose 6-phosphate or fructose 6-phosphate, but not by glucose. Iodoacetate, however, markedly increased the loss of haemoglobin and slightly increased that of lactate dehydrogenase. Phospholipase C greatly accelerated the relase of haemoglobin, lactate dehydrogenase, pyruvate kinase, hexokinase, glucose 6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase from human erythrocytes, but this effect was also reduced in the presence of ATP or ADP. The loss of lactate dehydrogenase, malate dehydrogenase, and pyruvate kinase from the cells treated with phospholipase C increased as their ATP content fell. In a series of experiments in which the action of phospholipase C was stopped by the subsequent addition of trypsin, ATP and ADP (1 mmol/l) significantly reduced the efflux of haemoglobin, but AMP had no such effect. The results are consistent with the conclusion from our previous work that enzyme leakage is related to diminution in the energy content of the cells. The protective action of AMP on cells not treated with phospholipase C, however, differs from earlier findings with rat lymphocytes and it is suggested that in red cells it might be converted into ATP or that it has a direct effect on the permeability of the cell membrane.

Enzyme Activity in the Platelets of Newborn Infants

PEDIATRICS ◽  
1970 ◽  
Vol 45 (3) ◽  
pp. 472-473
Author(s):  
Frank A. Oski ◽  
Scott Murphy ◽  
Frank H. Gardner
Keyword(s):  
Enzyme Activity ◽  
Pyruvate Kinase ◽  
Newborn Infants ◽  
Phosphoglycerate Kinase ◽  
Biochemical Properties ◽  
Transaminase Activity ◽  
Glutamic Oxaloacetic Transaminase ◽  
Glucose 6 Phosphate Dehydrogenase

Platelet hexokinase, phosphofructokinase, phosphoglycerate kinase, enolase, pyruvate kinase, lactic dehydnogenase, glucose-6-phosphate, dehydrogenase, and glutamic-oxaloacetic transaminase activity was assayed in platelets from newborn infants and contrasted with those of adults. Platelet phosphofnuctokinase activity was decreased and platelet phosphoglycerate kinase and glutamic-oxaloacetic transaminase activity were elevated in the platelets of newborn infants. It would appear that certain biochemical properties of the erythrocytes of the newborn are shared by the platelets as well. The metabolic consequences of these differences remain to be explored.

scholarly journals Activity and androgenic control of glycolytic enzymes in the epididymis and epididymal spermatozoa of the rat

1976 ◽  
Vol 156 (3) ◽  
pp. 527-537 ◽  
Author(s):  
D E Brooks
Keyword(s):  
Phosphoglycerate Kinase ◽  
Glycolytic Enzymes ◽  
Phosphoglycerate Mutase ◽  
Enzyme Release ◽  
Glycerol Phosphate ◽  
Phosphogluconate Dehydrogenase ◽  
Duct Ligation ◽  
Epididymal Spermatozoa ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Glycerol Phosphate Dehydrogenase

1. Procedures were developed for the extraction and assay of glycolytic enzymes from the epididymis and epididymal spermatozoa of the rat. 2. The epididymis was separated into four segments for analysis. When rendered free of spermatozoa by efferent duct ligation, regional differences in enzyme activity were apparent. Phosphofructokinase, glycerol phosphate dehydrogenase and glucose 6-phosphate dehydrogenase were more active in the proximal regions of the epididymis, whereas hexokinase, lactate dehydrogenase and phosphorylase were more active in the distal segment. These enzymes were less active in the epididymis of castrated animals and less difference was apparent between the proximal and distal segments. However, the corpus epididymidis from castrated rats had lower activities of almost all enzymes compared with other epididymal segments. 3. Spermatozoa required sonication to obtain satisfactory enzyme release. Glycolytic enzymes were more active in spermatozoa than in epididymal tissue, being more than 10 times as active in the case of hexokinase, phosphoglycerate kinase and phosphoglycerate mutase. 4. The specific activities of a number of enzymes in the epididymis were dependent on the androgen status of the animal. These included hexokinase, phosphofructokinase, aldolase, glyceraldehyde phosphate dehydrogenase, phosphoglycerate kinase, pyruvate kinase, glycerol phosphate dehydrogenase, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and phosphorylase. 5. The caput and cauda epididymidis differed in the extent to which enzyme activities changed in response to an altered androgen status. The most notable examples were hexokinase, phosphofructokinase, aldolase, phosphoglycerate kinase, 6-phosphogluconate dehydrogenase and phosphorylase.

NADP-linked dehydrogenases in secreted milk

1985 ◽  
Vol 52 (4) ◽  
pp. 501-506 ◽  
Author(s):  
Murray R. Grigor ◽  
Peter E. Hartmann
Keyword(s):  
Mammary Gland ◽  
Lactate Dehydrogenase ◽  
Malate Dehydrogenase ◽  
Isocitrate Dehydrogenase ◽  
Malic Enzyme ◽  
Prolonged Storage ◽  
Phosphogluconate Dehydrogenase ◽  
The Absolute ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Accurate Reflection

SUMMARYThe activities of glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, isocitrate dehydrogenase, malic enzyme, lactate dehydrogenase and malate dehydrogenase have been determined in secreted milk from sows, rats and rabbits. Within each species, although there was considerable variation in the absolute activities of these enzymes, the relative activities were similar to those observed for, or previously published for mammary homogenates. The only exception was milk glucose 6-phosphate dehydrogenase which tended to lose activity upon prolonged storage in the mammary gland. These results suggest that the pattern of milk enzymes can be an accurate reflection of that occurring in the mammary gland.

scholarly journals Dietary and hormonal regulation of L-type pyruvate kinase gene expression in rat small intestine

1987 ◽  
Vol 166 (2) ◽  
pp. 365-370 ◽  
Author(s):  
Helene OGIER ◽  
Arnold MUNNICH ◽  
Stanislas LYONNET ◽  
Sophie VAULONT ◽  
Gerard REACH ◽  
...  
Keyword(s):  
Gene Expression ◽  
Small Intestine ◽  
Pyruvate Kinase ◽  
Hormonal Regulation ◽  
Rat Small Intestine ◽  
Kinase Gene

scholarly journals Adaptation of the small intestine during pregnancy and lactation in the rat

1979 ◽  
Vol 184 (2) ◽  
pp. 245-251 ◽  
Author(s):  
K Burdett ◽  
C Reek
Keyword(s):  
Small Intestine ◽  
Lactate Dehydrogenase ◽  
Isocitrate Dehydrogenase ◽  
Enzyme Activities ◽  
Unit Area ◽  
Mucosal Epithelium ◽  
Pregnancy And Lactation ◽  
Enzyme Change ◽  
Specific Activities ◽  
Glucose 6 Phosphate Dehydrogenase

During pregnancy and lactation in the rat the small intestine in general and the mucosal epithelium in particular gain weight. The specific activities of sucrase, lactate dehydrogenase and succinate-tetrazolium reductase remain constant and those of glucose 6-phosphate dehydrogenase and isocitrate dehydrogenase increase. There is no evidence that the reported decrease in absorption per unit area or weight of mucosal epithelium during pregnancy and lactation is due to decreases in enzyme activities within the epithelium. The pattern of enzyme change shows that the response of the gut to the stimuli of pregnancy and lactation must be a complex one, possibly involving increases in the specific activities of some enzymes.

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.

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