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)

Effects of glucose concentration and anoxia upon the metabolite concentrations and rates of glycolysis and respiration have been investigated in the perfused liver of the fetal guinea pig. In most cases the metabolite concentrations in the perfused liver were similar to those observed in vivo. Between 50 days and term there was a fall in the respiratory rate and in the concentration of ATP and fructose 1,6-diphosphate and an increase in the concentration of glutamate, glycogen and glucose. Reducing the medium glucose concentration from 10 mM to 1 mM or 0.1 mM depressed lactate production and the concentration of most of the phosphorylated intermediates (except 6-phosphogluconate) in the liver of the 50-day fetus. This indicates a fall in glycolytic rate which is not in accord with the known kinetic properties of hexokinase in the fetal liver. Anoxia increased lactate production by, and the concentrations of, the hexose phosphates ADP and AMP in the 50-day to term fetal liver, while the concentration of ribulose 5-phosphate, ATP and some triose phosphates fell. These results are consistent with an activation of glycolysis, particularly at phosphofructokinase and of a reduction in pentose phosphate pathway activity, particularly at 6-phosphogluconate dehydrogenase. The calculated cytosolic NAD+/NADH ratio for the perfused liver was similar to that measured in vivo and evidence is presented to suggest that the dihydroxyacetone phosphate/glycerol 3-phosphate ratio gives a better indication of cytosolic redox than the lactate/pyruvate ratio. The present observations indicate that phosphofructokinase hexokinase and possibly pyruvate kinase control the glycolytic rate and that glyceraldehyde-3-phosphate dehydrogenase is at equilibrium in the perfused liver of the fetal guinea pig.
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PMID:Some effects of glucose concentration and anoxia on glycolysis and metabolite concentrations in the perfused liver of fetal guinea pig. 2 74

The activity of enzymes regulating the processes providing functional activity of leukocytes was studied in the exudate leukocytes of healthy rabbits and animals with alloxan diabetes. Rabbits with diabetes displayed a reduction of hexokinase, phosphoglucomutase, glucose-6-phosphate dehydrogenase and adenylate kinase activity. The activity of UDPH-pyrophosphorylase, UDPH-glycogentranspherase, 6-phosphogluconate dehydrogenase and glutathion reductase showed no significant changes in the exudate leukocytes in diabetes. A reduction of hexokinase and glucose-6-phosphate dehydrogenase limiting glycolysis and the pentose-phosphate cycle, respectively, providing energy for leukocytes and important in protein metabolism of these cells, is of great significance in the reduction of functional activity of leukocytes in the inflammatory focus in diabetes.
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PMID:[Enzymatic profile of the exudate leukocytes in diabetes mellitus]. 9 55

A congenital erythrocyte pyruvate kinase (PK) deficiency was found in a 72-year old female patient with chronic myelomonocytic leukemia (CMML). Erythrocyte PK deficiency was associated with an increase in the activity of hexokinase, 6-phosphogluconate dehydrogenase and glutathione peroxidase in erythrocytes as well as a decrease in acetylcholinesterase, glutathione reductase and glucosephosphate isomerase activities. The enzymatic abnormalities were accompanied by alterations in hemoglobin and in i antigen content of erythrocyte membrane. In addition, bone marrow ultrastructural studies showed dyshemopoietic changes in all blood cell lines and especially in erythroblasts. The present findings confirm the close relationship between CMML and acquired dyserythropoietic syndromes and constitute a new observation of the infrequent association of hereditary erythrocyte enzymopathies and leukemia. A survey of the literature is presented.
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PMID:Chronic myelomonocytic leukemia associated with hereditary pyruvate kinase deficiency and multiple acquired erythrocyte abnormalities. 10 94

The R3230AC mammary adenocarcinoma was not dependent on insulin; tumor growth was equal to or greater in diabetic rats than in intact animals. However, tumor growth was reduced when daily doses of insulin were administered. Treatment with estrogen inhibited growth of the R3230AC carcinoma, either in diabetic rats or in intact animals simultaneously treated with insulin. The effects of insulin plus estrogen treatment appeared to be additive in causing inhibition of tumor growth. Tumors from diabetic rats showed few metabolic alterations as reflected by little or no changes in the activities of selected glycolytic enzymes, pyruvate kinase, phosphofructokinase, and hexokinase, nor any striking changes in the activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, representing the pentose phosphate pathway. A modest reduction in the ratio of utilization of (1-14C)glucose: (6-14C)glucose was seen in vitro by tumors from diabetic rats. It was concluded that insulin, along with estrogen and prolactin, should be considered as a hormonal factor that influences growth of this automonous, hormone-responsive adenocarcinoma.
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PMID:Influence of insulin on estrogen-induced responses in the r3230ac mammary carcinoma. 12 68

Adipose tissue and liver from vitamin B6-deficient rats have an increased lipogenic capacity. Whether this phenomenon is accompanied by changes in the activities of certain enzymes involved in the metabolism of carbohydrate and lipid, or by altered transport of glucose into adipocytes, has been studied. Five glycolytic enzymes (hexokinase, phosphoglucose isomerase, phosphofructokinase, aldolase, and pyruvate kinase), two pentose phosphate pathway enzymes (glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase), malic enzyme, and ATP citrate lyase were measured in the epididymal adipose tissue, livers and kidneys of vitamin B6-deficient and control rats. Vitamin B6 deficiency did not significantly affect the glycolytic enzyme levels in the tissues studied, or the dehydrogenases measured in adipose tissue and kidneys. Liver glucose-6-phosphate dehydrogenase, and adipose tissue and liver malic enzyme were significantly lowered in deficient rats compared to ad libitum and pair-fed controls. Adipose tissue and liver ATP citrate lyase activities were also significantly decreased by vitamin B6 deficiency. In the presence of insulin, the uptake of glucose and 3-O-methyl glucose, a non-metabolizable sugar, by fat pads from deficient rats was greater than uptake by fat pads from control rats. These observations suggest that the increased glucose utilization by adipose tissue and liver of vitamin B6-deficient rats is not directly related to changes in the enzymes studied, but in the case of adipose tissue, may be explained, at least in part, by enhanced glucose uptake.
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PMID:Effects of vitamin B6 deficiency on liver, kidney, and adipose tissue enzymes associated with carbohydrate and lipid metabolism, and on glucose uptake by rat epididymal adipose tissue. 13 63

Enzyme activity declines with erythrocyte age in most mammals. To test this concept in the dog, we decreased the PCV to less than 20 by phlebotomy. The erythrocytes were restored rapidly (1.57 per cent per day). The resulting decline in the mean erythrocyte age was accompanied by increased activity by most of the erythrocyte enzymes studied. Enzymes with lower initial enzymatic activity (hexokinase, pyruvate kinase, 6-phosphogluconate dehydrogenase and glutathione reductase) increased proportionally more than those with higher initial activity (lactate dehydrogenase, 3-phosphoglycerate kinase, glyceraldehyde-3-dehydrogenase and glucose-6-dehydrogenase). Among species, increases in enzyme activity after phlebotomy appear to be related to each species' life span. Most of the metabolites increased concomitantly with the highest reticulocyte period. Diphosphoglycerate concentrations did not change significantly during the experiment.
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PMID:The effect of phlebotomy on canine erythrocyte metabolism. 16 7

Established epithelial cell lines derived from livers of 7-day (B, B-R, B-3-4-7, J-C-1, J-C-13, J-5-2-1, E-C-4 and E-C-7) and adult (AL-2, AL-3, AL-4, AL-5 and AL-6) rats were analyzed for hexokinase (HK), pyruvate kinase (PK), glucose 6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), glucose 6-phosphatase (G6Pase) and fructose 1,6-diphosphatase (FDPase). None of the cell lines showed appreciable activities of adult type liver enzymes (HK Type IVs (glucokinase), PK Type L, G6Pase and FDPase). On the contrary, the activities of fetal type liver enzymes (HK Types I and II, PK Type M2 and G6PD) increased markedly as compared with dispersed cells or tissues of adult liver. 6PGD gave minimum changes in activity, and the 6PGD/G6PD ratio decreased consistently. HK Type III was found only in J-C-13, AL-5 and AL-6, while HK Type IVf (high Km) was present in all the cell lines examined. Possible explanations for the undifferentiated patterns of carbohydrate-metabolizing enzymes in the established cell lines, which have several evidence of hepatocyte origin, are presented.
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PMID:Undifferentiated patterns of key glycolytic and gluconeogenic enzymes in epithelial cell lines derived from rat liver. 16 73

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.
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PMID:Activity and androgenic control of glycolytic enzymes in the epididymis and epididymal spermatozoa of the rat. 18 56

Age alterations in the activity of several key enzymes of glucose oxidative breakdown (hexokinase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and cytochrome c oxidase) were studied in extracts from rabbit aorta. The hexokinase activity was measured also in mitochondrial fraction. The activity of all the enzymes studied in rabbit aorta (calculated either per 1 g of the tissue or per 1 mg of proteins) was the highest at the age from 1-2 weeks to 1 month. The minimal activity was observed in adult animals, which were 1-2 years old, In aorta of 3,5-4 years old rabbits an increase (per 1 g of the tissue) in the activity of the enzymes was observed.
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PMID:[Age and changes in the activity of several energy metabolism enzymes in the rabbit aorta]. 20 2

A procedure is described to prepare uniformly labelled D-[14C]ribulose 1,5-bisphosphate enzymically from uniformly labelled D-[14C]glucose through the coupled reactions catalysed by hexokinase (EC 2.7.1.1), glucose 6-phosphate dehydrogenase (EC 1.1.1.49), 6-phosphogluconate dehydrogenase (EC 1.1.1.44) and 5-phosphoribulokinase (EC 2.7.1.19). All reagents utilized in the method are commercially available. The procedure is a reliable preparative-scale method for synthesizing the dibarium salt of D-[14C]ribulose 1,5-biphosphate with a specific radioactivity up to 7 mCi/mmol and a purity near 90%. The final product was free of other 14C-labelled sugars, sugar phosphate esters, Pi and nucleotides.
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PMID:Preparative-scale enzymic synthesis of D-[14C]ribulose 1,5-bisphosphate. 21 56


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