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)

A study of post-mortem changes in human central nervous tissue has shown that within 100 h of death, no significant change occurs in the amount of nerve cell DNA and nucleolar RNA nor in some membrane-associated enzymes such as succinate dehydrogenase, NADH and NADPH diaphorase, and cytochrome oxidase. Low molecular weight RNA species, probably transfer and messenger RNA are quickly lost, but there is little alteration in ribosomal RNA content. Cytoplasmic enzymes show variable changes; phosphofructokinase activity is rapidly decreased; hexokinase is unaltered but lactate dehydrogenase, pyruvate kinase and glucose-6-phosphate dehydrogenase initially show increases in activity which subsequently decline. Oxygen uptake diminishes quickly. These findings indicate that mechanical alterations in cell structure, following death, render organelles physiologically ineffective long before any significant changes in certain constituent biochemicals are detected. This report emphasizes the great importance necessary in the selection of appropriately time matched post-mortem tissues if accurate comparative studies of many of the cells constituents are to be made.
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PMID:Post-mortem changes in human central nervous tissue and the effects on quantitation of nucleic acids and enzymes. 14 55

The effects of exposure of glial cells in primary culture and in continuous line (clone NN) to pentobarbital over various periods of time on cellular respiration and activities of enzymes involved in carbohydrate metabolism were studied. The results obtained in glial cells in primary culture were qualitatively identical to those obtained in glial cells in clonal line (NN). Both types of glial cells were shown to develop biochemical tolerance to pentobarbital as defined by an attenuated response to the depressant effects of a challenging dose of pentobarbital on cellular respiration in barbiturate-cultivated cells compared to those grown in drug-free medium. The biochemical tolerance was evident in the presence of glucose and succinate but not malate as substrate. This tolerance to pentobarbital was accompanied by increased activities of hexokinase, glucose-6-phosphate dehydrogenase, succinate dehydrogenase, and glutamate dehydrogenase and by a marked increase in the number of glial cell mitochondria as observed in electron micrographs. The results are interpreted to indicate a compensation of glial cells to the continuous presence of PB by an accelerated glucose uptake and metabolism, an accelerated metabolism of succinate, and an increased mitochondrial activity.
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PMID:Development and mechanism of barbiturate tolerance in glial cell cultures. 15 11

The activity of the following enzymes was studied in normal, precancerous, and malignant biopsies from the human cervix uteri: hexokinase (HK), phosphofructokinase (PFK), pyruvate-kinase (PK), lactate dehydrogenase (LDH), and glucose-6-phosphate dehydrogenase (G-6-PDH). In precancerous conditions, i.e., dysplasia and carcinoma in situ without any signs of invasive carcinoma, only PK showed moderate but significant activity increases. A rise in enzyme activity in biopsies histologically classified as carcinoma in situ was found to signal the presence of invasive carcinoma in other parts of the cervix. In invasive carcinomas of the cervix, all the enzymes studied showed a two- to four-fold increase (p less than 0.01) as compared to the normal cervix. The present study failed to reveal significant differences between enzyme activities in biopsies from patients in Stage I, II, and III; no correlation could be established between enzyme activity and prognosis.
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PMID:The glycolytic enzyme activity of the human cervix uteri. 16 34

Development of cirrhosis of liver tissue did not influence the intensity of glycolysis, with glucose as a substrate, in supernatant fraction of liver homogenate in chronic intoxication with CCL4. In preparations of cirrhotic liver, as compared with liver from the intact animals, more distinct activation of glycolysis was caused by addition of ATP and NAD at the stage of 3-week intoxication and also by addition of hexokinase, glyceraldehydephosphate dehydrogenase and lactate dehydrogenase at the stage of distinct cirrhosis of liver (6 weeks of CCL4 intoxication). Km values for glucose-6-phosphate dehydrogenase increased over all the periods of intoxication.
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PMID:[Change in the glycolytic and glucose-6-phosphate dehydrogenase activity in experimental cirrhosis of the liver]. 16 85

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

The activities (Vmax) of hexokinase, glycogen phosphorylase, glucose-6-phosphate dehydrogenase, phosphofructokinase, lactate dehydrogenase, citrate synthase, cytochrome c oxidase, and 3-OH-acyl-CoA dehydrogenase in human skeletal muscles were compared with the in vitro utilization of glucose and palmitic acid assessed under optimal conditions. Statistically significant correlations between substrate fluxes and enzyme activities were found suggesting that the substrate incorporation rate in vitro in some way reflects the capacity of metabolic pathways. The incorporation rate of leucine into muscle proteins was also statistically significantly correlated to the RNA concentration in the muscle tissue. Glycolytic and glycogenolytic enzymes correlated significantly to each other and correlations were also found between aerobic enzymes supporting the validity of constant proportions between certain key enzymes in human skeletal muscles.
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PMID:Incorporation rate of glucose carbon, palmitate carbon and leucine carbon into metabolites in relation to enzyme activities and RNA levels in human skeletal muscles. 17 28

The pathway of glucose metabolism in Pseudomonas aeruginosa was regulated by the availability of glucose and related compounds. On changing from an ammonium limitation to a glucose limitation, the organism responded by adjusting its metabolism substantially from the extracellular direct oxidative pathway to the intracellular phosphorylative route. This change was achieved by repression of the transport systems for gluconate and 2-oxogluconate and of the associated enzymes for 2-oxogluconate metabolism and gluconate kinase, while increasing the levels of glucose transport, hexokinase and glucose 6-phosphate dehydrogenase. The role of gluconate, produced by the action of glucose dehydrogenase, as a major inhibitory factor for glucose transport, and the possible significance of these regulatory mechanisms to the organism in its natural environment, are discussed.
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PMID:The role of glucose limitation in the regulation of the transport of glucose, gluconate and 2-oxogluconate, and of glucose metabolism in Pseudomonas aeruginosa. 17 10

The activity of the glycolytic enzymes and of the glucose-6-phosphate dehydrogenase (G-6-PDH) were compared with the content of noradrenaline in rat myocardium and the liver after the intraperitoneal injection of high doses of noradrenaline. It was shown that 24 hours after int noradrenaline injection which caused exhaustion of endogenous catecholamine supply, the lactate content and the activities of lactic dehydrogenase were increased in the myocardium; the activity of hexokinase and G-6-PDH in rat myocardium and the liver were also increased, whereas the glucokinase activity was decreased. In these experiments alterations of the enzyme activities were shown to be similar to the alterations in the dystrophic tissues in which the catecholamine content was sharply decreased. The role of the sympathetic nervous system and its mediators in the mechanism of the enzyme regulation of the energy metabolism in the myocardium and the liver is discussed.
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PMID:[Activity of energy metabolism related enzymes in the myocardium and liver following administration of large doses of noradrenaline]. 17 88

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

A surgical specimen of solitary, encapsulated tumor tissue obtained from a 52-year-old male, diagnosed histologically as well-differentiated hepatocellular carcinoma (Grade II, Edmondson and Steiner) with liver cirrhosis, Type A' (and B is some parts), was found to have a supernormal level of pyruvate kinase Type L and subnormal level of Type M2; the activities (units/mg protein) being 1.21 and 0.12 respectively. The resulting isozyme pattern was apparently "superdifferentiated" as compared with those of not only the tumor-bearing, cirrhotic liver (Type L, 0.19; Type M2, 0.67) but also the normal liver (Type L, 0.47+/-0.05; Type M2, 0.18+/-0.02). The electrophoretic and kinetic properties of the type L isozyme were identical with those of the cirrhotic host liver and a non-cirrhotic control liver. Other enzyme levels in the hepatoma tissue were as follows: Glucose-6-phosphatase, norma; fructose-1,6-bisphosphatase, reduced; glucokinase, absent; and hexokinase Types I and III, and glucose-6-phosphate dehydrogenase, slightly increased. The serum alpha-fetoprotein level was 95 ng/ml. The whole enzyme profile is consistent with the minimal deviation hepatomas in rats. The results were compared with those of other human hepatomas, and the mechanisms of disordered regulation in hepatoma gene expression were discussed.
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PMID:A case of minimal deviation hepatoma in man with elevated liver-type pyruvate kinase isozyme. 19 53


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