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)

1. Adipose tissues from rats fed a balanced diet were incubated in the presence of glucose (20mm) with the following additions: insulin, anti-insulin serum, insulin+acetate, insulin+pyruvate, insulin+lactate, insulin+phenazine methosulphate, insulin+oleate+albumin, insulin+adrenaline+albumin, insulin+6-N-2'-O-dibutyryl 3':5'-cyclic AMP+albumin. 2. Measurements were made of the whole tissue concentrations of adenine nucleotides, hexose phosphates, triose phosphates, glycerol 1-phosphate, 3 phosphoglycerate, 6-phosphogluconate, long-chain fatty acyl-CoA, acid-soluble CoA, citrate, isocitrate, malate and 2-oxoglutarate, and of the release into the incubation medium of lactate, pyruvate and glycerol after 1h of incubation. 3. Fluxes of [(14)C]glucose carbon through the major pathways of glucose metabolism were calculated from the yields of (14)C in various products after 2h of incubation. Fluxes of [(14)C]acetate, [(14)C]pyruvate or [(14)C]lactate carbon in the presence of glucose were also determined. 4. Measurements were also made of the whole-tissue concentrations of metabolites in tissues taken directly from Nembutal-anaesthetized rats. 5. Whole tissue mass-action ratios for phosphofructokinase, phosphoglucose isomerase and the combined (aldolasextriose phosphate isomerase) reaction were similar in vivo and in vitro. The reactants of phosphofructokinase appeared to be far from mass-action equilibrium. In vitro, the reactants of hexokinase also appeared to be far from mass-action equilibrium. 6. Correlation of observed changes in glycolytic flux with changes in fructose 6-phosphate concentration suggested that phosphofructokinase may show regulatory behaviour. The enzyme appeared to be activated in the presence of oleate or adrenaline and to be inhibited in the presence of lactate or pyruvate. 7. Evidence is presented that the reactants of lactate dehydrogenase and glycerol 1-phosphate dehydrogenase may be near to mass-action equilibrium in the cytoplasm. 8. No satisfactory correlations could be drawn between the whole-tissue concentrations of long-chain fatty acyl-CoA, citrate and glycerol 1-phosphate and the observed rates of triglyceride and fatty acid synthesis. Under the conditions employed, the concentration of glycerol 1-phosphate appeared to depend mainly on the cytoplasmic [NAD(+)]/[NADH] ratios. 9. Calculated hexose monophosphate pathway flux rates roughly correlated with fatty acid synthesis rates and with whole tissue [6-phosphogluconate]/[glucose 6-phosphate] ratios. The relative rates of production of NADPH for fatty acid synthesis by the hexose monophosphate pathway and by the ;malic enzyme' are discussed. It is suggested that all NADH produced in the cytoplasm may be used in that compartment for reductive synthesis of fatty acids, lactate or glycerol 1-phosphate.
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PMID:The regulation of triglyceride synthesis and fatty acid synthesis in rat epididymal adipose tissue. 439 81

Just before birth, changes occur in the metabolic capacities of rat liver so that the animal can adapt to changes in the substrate supply. In utero, glucose is the main energy-generating fuel and the liver metabolism is directed towards glucose degradation. The activities of the rate-limiting enzymes of glycolysis, hexokinase and phosphofructokinase, are high. In preparation for post-natal life, when the continuous glucose supply from the mother is interrupted, very large amounts of glycogen are stored in the late fetal liver. With the intake of the fat-rich and carbohydrate-poor milk diet, the animal develops the ability to synthesize glucose de novo from non-carbohydrate precursors. During suckling, metabolic energy is derived mainly from the beta-oxidation of fatty acids, which in turn is an essential prerequisite for the high rate of gluconeogenesis, by yielding acetyl-CoA for the activation of pyruvate carboxylase and by generating a high NADH/NAD ratio for the shift of the glyceraldehyde 3-phosphate dehydrogenase reaction in the direction of glucose formation.--The developmental adaptation of metabolism and the process of enzymatic differentiation are closely connected with the maturation of the endocrine system and the changes in the concentration of circulating hormones. The neonatal regulation of phosphoenolpyruvate carboxykinase and of tyrosine aminotransferase by variations in the hormonal milieu around birth, and also the interaction of hormonal and nutritional factors in the induction of serine dehydratase and glucokinase at the end of the suckling period, will be discussed in detail.
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PMID:Biochemistry of liver development in the perinatal period. 613 74

The accumulations by axoplasmic transport of selected enzyme activities proximal and distal to a ligature placed on the sciatic nerve were monitored in rats exposed in utero to maternal antibodies to nerve growth factor (NGF) and in control rats. Littermates of the animals exposed to anti-NGF were shown elsewhere to have had a 70% reduction in the number of sensory neurons in dorsal root ganglia and a 90% reduction in number of neurons in superior cervical (sympathetic) ganglion. The accumulation of F(-)-sensitive acid phosphatase activity was depressed 75% both proximal and distal to the tie. Accumulation of F(-)-resistant acid phosphatase activity was depressed nearly 50% proximal to the tie. Distal accumulation of this activity did not occur in either group of rats. Accumulation of acetylcholinesterase activity was depressed 30%. Distal accumulation of the activities of beta-glucuronidase and hexokinase was depressed 50%. In the lumbar dorsal root ganglia, dry weight was reduced 40%, and the activities of peroxide-sensitive, F(-)-resistant acid phosphatase and of the mitochondrial enzymes hexokinase, glutamic dehydrogenase, glutamic-oxalacetic transaminase, and NAD-dependent isocitric dehydrogenase were all reduced a little more, 45--50% per ganglion. However, the activities of the lysosomal enzymes, F(-)-sensitive acid phosphatase and beta-glucuronidase, of the peroxide-resistant, F(-)-resistant acid phosphatase, and of the mitochondrial enzyme glutaminase were all reduced about 60% per ganglion. The results of these measurements were interpreted to suggest that much, and perhaps all, of the F(-)-sensitive acid phosphatase activity in motion in peripheral nerve in rat is confined to sensory axons.
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PMID:Transported enzymes in sciatic nerve and sensory ganglia of rats exposed to maternal antibodies against nerve growth factor. 616 7

The quantitative assay of hexokinase (HK), phosphorylase, phosphofructokinase (PFK), glucose 6-phosphate dehydrogenase (G-6-PDH), glycerol 3-phosphate dehydrogenase (G-3 PDH) and lactate dehydrogenase (LDH) revealed that coxal muscles compared to hepatopancreas contained higher activities of all the enzymes investigated. It appears that the coxal muscles of the premolt field crab has carbohydrate-based fuel economy. The hepatopancreas is a rich source of lipid and very poor source of glycogen. The activity of G-6-PDH is moderately high in the hepatopancreas. It seems that in this lipogenic tissue conversion of G-6-P to triose phosphate occurs predominately via pentose-phosphate pathway thus generating NADPH for lipogenesis. The relative G-3PDH ad LDH activities in hepatopancreas and coxal muscles led us to believe that the reconversion of NAD from NADH in hepatopancreas nd muscle flexor is effected by glycerol 3-phosphate shuttle, whereas in muscle extensor it is achieved by both G-3PDH and LDH activities.
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PMID:Glycolytic enzymes in the premolt field crab Paratelphusa hydrodromus (Milne-Edwards) (Crustacea). 619 88

The effect of 5 days' complete fasting on the activity of 7 enzymes of energy supplying metabolism was studied in the vastus lateralis muscles of 9 healthy male volunteers. There was a significant decrease of lactate dehydrogenase (by 66%), triosephosphate dehydrogenase (by 61%), malate:NAD dehydrogenase (by 48%), hexokinase (by 40%), 3-hydroxyacyl-CoA-dehydrogenase (by 40%), triosephosphate dehydrogenase/3-hydroxyacyl-CoA-dehydrogenase (by 35%), citrate synthase (by 33%). Glycerolphosphate:NAD dehydrogenase activity did not decrease significantly. These findings suggest a) that utilization of the major energy substrates decreases; b) that the decrease mainly concerns the catabolism of carbohydrates, that of fatty acids to a lesser extent; c) that the decreased capacity of carbohydrate catabolism is partly compensated for by the predominance of the more economic aerobic-oxidative pathway; d) that the reducing equivalents formed in the cytosol may be transported via the glycerolphosphate shuttle into the respiratory chain to a greater extent, so that a greater portion is not lost by the reduction of pyruvate to lactate.
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PMID:Activities of muscle energy supplying enzymes after 5 days complete fasting in young men. 621 60

1. In rat kidney cortex, outer and inner medulla the development of activities of seven enzymes was investigated during postnatal ontogeny (10, 20, 30, 60 and 90 days of age). The enzymes were selected in such a manner, as to characterize most of the main metabolic pathways of energy supplying metabolism: hexokinase (glucose phosphorylation, HK), glycerol-3-phosphate dehydrogenase (glycerolphosphate metabolism or shunt, GPDH), triose phosphate dehydrogenase (glycolytic carbohydrate breakdown, TPDH), lactate dehydrogenase (lactate metabolism, LDH), citrate synthase (tricarboxylic acid cycle, aerobic metabolism, CS), malate NAD dehydrogenase (tricarboxylic acid cycle, intra-extra mitochondrial hydrogen transport, MDH) and 3-hydroxyacyl-CoA-dehydrogenase (fatty acid catabolism, HOADH). 2. The renal cortex already differs metabolically from the medullar structures on the 10th day of life. It displays a high activity of aerobic breakdown of both fatty acids and carbohydrates. Its metabolic capacity further increases up to the 30th day of life. 3. The outer medullar structure is not grossly different from the inner medulla on the 10th day of life. Further it differentiates into a highly aerobic tissue mainly able to utilize carbohydrates. It can, however, to some extent, also utilize fatty acids aerobically and produce lactate from carbohydrates anaerobically. 4. The inner medullar structure is best equipped to utilize carbohydrates by anaerobic glycolysis, forming lactate. This feature is already pronounced on the 10th day of life, its capacity increases to some extent during postnatal development, being highest between the 10th and the 60th day of life.
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PMID:Postnatal changes of some enzymatic activities of energy supplying metabolism in the cortex, inner and outer medulla of the rat kidney. 644 14

In aggregates of nervous tissue, cultivated for 1--7 days at 0 degree C and 37 degrees C, respectively, the activities of seven enzymes of energy liberating metabolism were estimated, in order to evaluate their metabolic "profiles" and changes during cultivation. The enzymes used as markers of different pathways of energy liberation from substrates were: lactate dehydrogenase - LDH - (EC 1.1.1.27), triose-3-phosphate dehydrogenase - TPDH - (EC 1.2.1.12), glycerol-3-phosphate dehydrogenase - GPDH - (EC 1.1.1.8), hexokinase - HK - (EC 2.7.1.1.), malate:NAD dehydrogenase - MDH - (EC 1.1.1.37), citrate synthase - CS - (EC 4.1.3.7), and 3-hydroxyacetyl CoA dehydrogenase - HOADH - (EC 1.1.1.35). During the cultivation, some changes in the metabolic "profiles" were observed. Although some of these changes as well as the differences between the cultivation at 0 degree C and 37 degrees C, were statistically significant, they were not greater than the variations between different samples of any tissue taken at different times. They were not, therefore considered to be of major significance. However, all the aggregates exhibited "profiles" characteristic for the nervous tissue, with relatively very high activity of HK, high activity of MDH and CS (carbohydrate breakdown) and low activity of GPDH and HOADH (lipid catabolism).
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PMID:Enzyme activity pattern in developing mouse brain in situ in embryonic brain aggregated cells at 37 degrees C and 0 degree C. 661 8

The activity of NAD-linked alpha-glycerol-3-phosphate dehydrogenase (NAD-G3PDH; EC 1.1.1.8) was depressed by 35% when the thyroid hormone 3,3',5-triiodo-L-thyronine (20 micrograms/liter) was added to the serum-free, hormonally supplemented medium of cultured neonatal rat heart cells. The degree of depression was greater (65%) when the medium contained normal serum levels of hydrocortisone and insulin. There is a dramatic inverse dose-response relationship between triiodothyronine levels and NAD-G3PDH activity. The classic elevation by thyroid hormones of the FAD-linked alpha-glycerol-3-phosphate dehydrogenase (FAD-G3PD; EC 1.1.99.5) was observed concurrently. The medium-glucose depletion rate in triiodothyronine-free cells was depressed 32% through 11 days-in-culture, indicating reduced glycolytic activity. The activities of nine other metabolically important enzymes which were measured during this study, including hexokinase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, phosphofructokinase, pyruvate kinase, malate dehydrogenase, NAD-isocitrate dehydrogenase, NADH cytochrome c reductase, and succinic cytochrome c reductase, did not respond to varying triiodothyronine concentrations.
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PMID:Triiodothyronine depresses the NAD-linked glycerol-3-phosphate dehydrogenase activity of cultured neonatal rat heart cells. 669 42

A serum-free, hormone-supplemented medium (SFHM) for maintaining neonatal rat heart cells in culture has been developed in this laboratory (Mohamed et al., 1983). Morphological assessment of heart cells grown in SFHM show it to be similar to commonly used serum-supplemented media. To quantitatively compare cell behavior in SFHM with serum-supplemented media, the activities of ten regulatory enzymes which represent four metabolic pathways were studied in heart cells cultured in SFHM. The enzyme activities which were measured included hexokinase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, phosphofructokinase, pyruvate kinase, NAD+-linked sn-glycerol-3-phosphate dehydrogenase, malate dehydrogenase, NAD+-linked isocitrate dehydrogenase, NADH-cytochrome c reductase, and succinic cytochrome c reductase. Rat heart cells maintained in culture on SFHM are not only qualitatively and quantitatively similar to those maintained in serum-supplemented medium but also provide a more suitable model system for metabolic studies of neonatal cardiac tissue for several reasons: 1) many enzyme activities that may represent dedifferentiation are elevated by serum; 2) NAD-linked glycerol-3-phosphate dehydrogenase activity in cells maintained on SFHM is similar to the in vivo activity; 3) cells beat at or near the in vivo frequency and can be maintained 3 months on SFHM; 4) the SFHM is chemically defined and thus can be completely manipulated by the investigator. The effects of three concentrations of hydrocortisone (HC) (5,000 ng/ml, 50 micrograms/ml, 0 ng/ml) on heart cells cultured in SFHM supported our previous conclusion that function (beating) and growth (protein accumulation) are inversely related in cultured neonatal rat heart cells.
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PMID:Control of enzyme activity levels by serum and hydrocortisone in neonatal rat heart cells cultured in serum-free medium. 674 46

In sections of rat tumors arisen after transplacental and postnatal exposure to BP, DMVA, and NEM there was found the activity of NAD. H2-tetrazole-oxydoreductase, hexokinase, succinate and lactate dehydrogenase, glucoso-6-phosphate, alpha-glycerophosphate, glutamate, acid and alklaine phosphatase. A comparison of the histological structure and histochemical properties of malignant tumors showed their being independent on the chemical structure, dosage and terms of the carcinogen administration. However, the malignant signs of tumors of various histogenesis varied not only between epithelial, neurogenic and mesenchymal type of tumors but also within each of the types concerned.
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PMID:[Enzymohistochemical study of the tumors from the transplacental and postnatal exposure to various carcinogens]. 676 96


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