Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.1.1 (hexokinase)
 5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The erythrocyte 2,3-diphosphoglycerate concentration (2,3-DPG) and the activity of red cell hexokinase, pyruvate kinase, glucose-6 phosphate dehydrogenase and glutathione reductase were studied in 27 normal volunteers before and after 2 and 4 months of physical endurance training. The 4 months of training increased maximal oxygen uptake and physical working capacity (PWC130) by 16% (p less than 0.001) and 29% (p less than 0.001) respectively. Resting heart rate was decreased (p less than 0.001) by 11 beats.min-1. With 2 months of training the erythrocyte 2,3-DPG concentration increased by 9% (p less than 0.001); with 4 months training the increase was only 4% (p less than 0.05). The training-induced increase in red cell 2,3-DPG was not accompanied by enhanced activity of erythrocyte hexokinase, pyruvate kinase, glucose-6 phosphate dehydrogenase or glutathione reductase. It is concluded that the rise in red cell 2,3-DPG induced by physical endurance training is not due to activation of red cell glycolytic enzymes or the enzymes involved in the pentose-phosphate cycle.
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PMID:Effects of training on erythrocyte 2,3-diphosphoglycerate in normal men. 339 60

Activities of the red cell enzymes hexokinase, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, lactic dehydrogenase and aspartate aminotransferase were measured in 17 chronic haemodialysis patients receiving androgen therapy, 15 untreated chronic haemodialysis patients and 15 normal subjects. Compared to normal subjects, untreated haemodialysis patients had similar reticulocyte counts but significantly increased levels of all five enzymes studied. This finding suggests the presence of a younger red cell population in the peripheral blood and is consistent with the shortened red cell survival known to occur in this clinical setting. Red cell enzyme activities in untreated haemodialysis patients were significantly correlated with one another and with the serum phosphate level. Moreover, in this population, red cell DPG content was directly related to hexokinase and glucose 6-phosphate dehydrogenase activities while haemoglobin-oxygen affinity (P50) was inversely related to all five enzyme activities. In contrast, in androgen-treated haemodialysis patients, despite higher reticulocyte counts, red cell enzyme activities were the same or lower than those in the untreated haemodialysis group and only slightly higher than those in normal subjects, suggesting an overall older red cell population. Moreover, relationships of red cell enzymes to one another, to serum phosphate levels and to both red cell DPG content and haemoglobin-oxygen affinity were significantly different in androgen-treated subjects than in the untreated haemodialysis group. These changes are consistent with a direct effect of androgens on red cell metabolism and an improved red cell survival during androgen therapy.
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PMID:Androgen therapy in haemodialysis patients. II. Effects on red cell metabolism. 382 30

Metabolic activity of erythrocytes was studied in healthy pregnant women. The second half of the normal pregnancy was characterized by an increase in activity of hexokinase, in content of 2,3-DPG, ADP, by a distinct decrease in ATP, NAD and the ratio ATP/ADP as well as by unaltered ratios NAD/NADH and lactate/pyruvate.
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PMID:[Glycolytic enzyme activity and levels of glycolysis metabolites in erythrocytes in physiological pregnancy]. 400 52

Red cell enzymes, 2,3-diphosphoglycerate (2,3-DPG) and adenosine triphosphate (ATP), were evaluated in a 23-mo-old boy with juvenile chronic myelocytic leukemia (JCML) at the onset of his illness and 6 mo later during the accelerated phase. The activities of the age-dependent red cell enzymes, hexokinase, aldolase, pyruvate kinase, and glucose-6-phosphate dehydrogenase, were elevated, as were the concentrations of red cell 2,3-DPG and ATP, consistent with a young red cell population metabolizing at an increased glycolytic rate. The activities of the non-age-dependent enzymes, glyceraldehyde-3-phosphate dehydrogenase (G3PD), phosphoglycerate kinase, and enolase, were also increased to levels similar to or greater than those observed in term infants. As the illness progressed, the activity of red cell G3PD increased further, and phosphoglucose isomerase activity increased markedly. These results are consistent with the prior suggestion that JCML represents a reversion to "fetal" erythropoiesis.
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PMID:Fetal erythropoiesis in juvenile chronic myelocytic leukemia. 622 20

The erythrocyte 2,3-diphosphoglycerate (2,3-DPG) concentrations of sheep change markedly during the 1st mo following birth. From measurements of erythrocyte glycolytic enzymes and intermediate concentrations, we have identified the mechanism regulating erythrocyte 2,3-DPG in postnatal sheep. The postnatal changes in erythrocyte 2,3-DPG do not result from qualitative or quantitative changes in the intracellular activities of the Rapoport-Luebering shunt enzymes, 2,3-DPG mutase or 2,3-DPG phosphatase. The postnatal 2,3-DPG changes result from changes in the erythrocyte concentration of 1,3-DPG, which is controlled by other reactions in the glycolytic pathway. Neither changes in the glycolytic control enzymes (hexokinase, phosphofructokinase, and pyruvate kinase) nor changes in the intrinsic glycolytic rate can account for these 1,3-DPG concentration changes. 1,3-DPG concentrations are regulated by the in vivo glycolytic rate, which is controlled by the intracellular concentration of glucose, the glycolytic substrate. Glucose concentrations are 0.3 mmol/l cells in erythrocytes of fetal sheep (135-140 days gestational age), increase following birth to a peak of 3.8 mmol/l cells by the 1st wk of age, and then decline to the normal adult levels of 0.5 mmol/l cells by the end of the 1st mo.
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PMID:Postnatal regulation of 2,3-DPG in sheep erythrocytes. 631 Oct 32

A metabolic osmotic model of red blood cells is presented which takes into account the main reaction steps of glycolysis and the passive and active fluxes of ions across the cell membrane. Cellular energy metabolism and osmotic behaviour are linked by the ATP consumption for the active transport of cations as well as by the osmotic action of the glycolytic intermediate 2,3-diphosphoglycerate (2,3-DPG). The model is based on a system of differential equations describing the metabolic reactions and transport processes. Further, two algebraic conditions for the osmotic equilibrium and the electroneutrality of the cell are considered. Using realistic system parameters the model allows the calculation of a great number of dependent variables, among them the cell volume, the concentrations of metabolites and ions and the transmembrane potential. Only stationary states are considered. The parameter dependence of important model variables is characterized by control coefficients. The main results are: (a) The volume of erythrocytes is mainly determined by the permeabilities of the leak fluxes of cations, the content of hemoglobin and the activity of the hexokinase-phosphofructokinase system of glycolysis; (b) Changes of volume affect the glycolytic rate mainly by changing the concentration of ATP which is a regulator of glycolysis; (c) A change in the membrane area may affect the other cell properties only if it is connected with variations of the number of active and leak sites of the membrane.
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PMID:A metabolic osmotic model of human erythrocytes. 652 55

The glycolytic intermediates of the red cells of 11 adult diabetic patients were compared with those of eight normal controls. A statistically significant elevation of glucose-6-P and fructose-6-P levels were correlated with the blood sugar levels and 2,3-DPG levels. The absence of a metabolic crossover point suggests that the effect of high levels of glucose may be exerted through regulation of the hexokinase step, itself, but the nature of the regulation cannot be deduced from the complex situation which exists in vivo.
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PMID:Red cell glycolytic intermediates in diabetic patients. 739 59

Concentrations of ATP and DPG, activities of 10 enzymes and the glycolytic rates were measured in the erythrocytes of 11 species of marsupials and two species of monotremes. Mean DPG concentrations were greater in the erythrocytes of marsupials than those of eutherian mammals. The opposite is true of ATP. Significant findings from the results of enzyme activities were: high activity of hexokinase (7.39 +/- 0.82 EU/g Hb) in the short-beaked echidna, pyruvate kinase (37.49 +/- 1.0 EU/g) Hb in bridled nailtail wallaby and glucose-6-phosphate dehydrogenase (G6PD; 41.66 +/- 1.24 EU/g Hb) in black-striped wallaby. About 6- to 7-fold difference in the activity of G6PD levels between the two species of wombats was confirmed. Glucose phosphate isomerase activity was also shown to be twice as high in the red cells of the common wombat compared with those of the southern hairy nosed wombat. There were wide variations in the glycolytic rate among the species examined.
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PMID:Comparative erythrocyte metabolism in marsupials and monotremes. 759 74

The age changes of 2,3-DPG concentration, 2,3-diphosphoglycerate mutase, hexokinase and pyruvate kinase activities in pigs erythroid cells during the first 10 days after birth have been investigated for study of the mechanism of blood oxygen-transport function regulation at the early stages of postnatal adaptation. It was established, that there are age peculiarities in young, mature and old erythrocytes metabolism in piglets during the transition to postnatal development. It was shown that the rise of 2,3-DPG, the allosteric effector of hemoglobin oxygen affinity level, is due to the increased activities of 2,3-diphosphoglycerate mutase and hexokinase after birth, that is particularly characteristic of the young pigs erythrocytes.
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PMID:[Activity of enzymes of glycolysis in pig erythrocytes in the neonatal period]. 774 43

This study was undertaken to assess the effect of propane-1,2-diol(PD) ingestion on carbohydrate metabolism in female rat erythrocytes. For this purpose, two different groups of adult albino female rats were treated orally with PD at two different dose levels of 73 and 294 mg 100 g-1 body wt. The blood samples drawn from the retro-orbital sinus prior to the treatment served as the controls, whereas the treated samples were collected at peak periods (1/2 and 2 h) 2 and 7 days after the treatment. A single dose of PD was found to elevate levels of blood glucose, lactate, pyruvate and the lactate/pyruvate ratio at the peak periods (P < 0.001) and after 2 days (P < 0.001) in both the groups. A significant (P < 0.05) increase in the contents of erythrocyte 2,3-diphosphoglycerate (2,3-DPG) was observed only at the peak periods. All these parameters returned to their base level after 7 days of treatment. The activities of hexokinase (HK), 2,3-diphosphoglycerate phosphatase (2,3-DPG Pase), lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G-6-PD), 6-phosphogluconate dehydrogenase (6-PGD) and aldehyde reductase II (AR II) declined markedly, whereas those of pyruvate kinase (PK) and aldose reductase increased as a result of PD ingestion. The changes in the activities of 2,3-DPG Pase and LDH were persistent up to 8 days post-treatment. The [14C]glucose flux through glycolysis and the hexose monophosphate shunt pathway in erythrocytes was found to be lowered (P < 0.001) in response to PD treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of propane-1,2-diol ingestion on carbohydrate metabolism in female rat erythrocytes. 844 Aug 77


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