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)

In this communication the results of applying various histochemical semipermeable membrane techniques to the localization of several enzymes in bovine and porcine heart are presented. The Purkinje fibers of the atrioventricular conducting system of the bovine heart differ from the myocardium proper in containing a greater activity of the glycolytic and gluconeogenetic enzymes--lactate dehydrogenase, glyceraldehyde-phosphate dehydrogenase, hexokinase, glucosephosphate isomerase and phosphoglucomutase, and less activity of the aerobic enzymes--NADH: nitroBT oxidoreductase and isocitrate dehydrogenase (NADP+). The metabolic reactions obtained with Purkinje fibers of the porcine heart are less pronounced. These histochemical findings are in accordance with the impression that Purkinje fibers, compared with the common myocardial fibers, have a higher rate of anaerobic metabolism and a lower rate of aerobic metabolism. The activity of the NADPH regenerating enzymes glucose-6-phosphate dehydrogenase and phosphogluconate dehydrogenase (decarboxylating), and the activity of acid hydrolases such as non-specific esterase and acid phosphatase is higher in the Purkinje fibers of both the bovine and porcine heart.
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PMID:Enzyme histochemical studies on the Purkinje fibers of the atrioventricular system of the bovine and porcine hearts. 66 82

The Glucose-Controlled Insulin Infusion System (Biostator) is a modular, computerized, feedback control system for dynamic control of blood glucose concentrations in diabetics. This on-line glucose analyzer for use with whole blood utilizes a novel enzyme (glucose oxidase)-membrane configuration and an electrochemical cell to measure the H202 generated. The analyzer exhibits both short- and long-range stability, and instrument response and analyte concentration are linearly related over the full range of clinical interest. The response is fast, accurate, and precise, and permits determination of blood glucose within 2 min from the moment the blood leaves the patient. Correlation studies were completed to show the agreement between the Biostator Glucose Analyzer and the FDA's recommended hexokinase/glucose-6-phosphate dehydrogenase procedure on whole blood (e.g., average per cent recovered for 11 concentrations between 250 and 900 mg/liter was: hexokinase, 95.6%, Biostator Analyzer, 95.9%; bias and SDd, respectively, at low, normal, and high glucose values were: 12 and 41 mg/liter at the 500 mg/liter level; 4 and 52 mg/liter at the 1000 mg/liter level, and 4 and 128 mg/liter at the 4000 mg/liter level). No appreciable interference is observed with above-normal concentrations of bilirubin, uric acid, creatinine, sodium salicylate, or dextran. Platelet adhesion, which tends to decrease the useful life of the membrane, has been significantly decreased.
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PMID:Development and evaluation of a glucose analyzer for a glucose controlled insulin infusion system ((Biostator). 67 60

Rabbit myeloid myelocaryocytes possessed higher activities of hexokinase (HK) and lactate dehydrogenase (LDH) as compared with those of erythroid cells. The lypolytic activity was twice as high in myeloid myelocaryocytes as in erythroid ones. Both strains of medullar cells did not differ in the activity of glucose-6-phosphate dehydrogenase (G6PD). But the isoenzyme spectra of G6PD varied distinctly in these cells; HK and LDH isoenzyme spectra were the same both in myeloid and erythroid cells. The enzymatic activity was altered dissimilarly in myeloid and erythroid cells after administration of hydrocortisone. In myeloid cells the HK activity was decreased, in the erythroid cells--the HK activity tended to increase and the lipolytic activity was decreased. Alterations in the isoenzyme spectra of G6PD and LDH, caused by hydrocortisone administration, exhibited similar patterns in myeloid and erythroid cells.
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PMID:[Isoenzyme spectrum and activity of several enzymes of bone marrow erythroid and myeloid cells in rabbits and changes in them under the influence of hydrocortisone]. 68 90

A new method of measuring glucose concentrations (Reflotest-Hypoglycemie) was tested on 141 serum samples and 119 capillary blood samples and compared with the hexokinase-glucose-6-phosphate dehydrogenase method. The Reflotest (reflectance meter) compared well with the reference test. Comparison of results with three sera measured by the method in six different laboratories indicated the accuracy of the test. Endogenous bilirubin, uric acid, and haematocrit values did not influence the result. The test is therefore suitable for quantitative measurements.
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PMID:[A simple and quick method for measuring low blood-glucose concentrations (author's transl)]. 71 Mar 5

Despite the presence of a marked decrease in liver protein content 48 h after a single injection of D-galactosamine, increased activities of glucose-6-phosphate dehydrogenase, low-Km hexokinase and pyruvate kinase type M2 were observed in the injured liver. Microsomal aniline hydroxylase activity and cytochrome P-450 content in liver decreased significantly in 48 h of galactosamine treatment but not in the first 2 h in contrast with carbon tetrachloride (CCL4) intoxication. The extents of those changes were not so great as in CCl4-treated rats. The disaggreation of polyribosomes in liver was observed in 24 h of galactosamine treatment. However, the formation of microsomal lipoperoxidation did not increase in the entire course of acute liver injury by the amino sugar. These results taken together with our previous observations indicate that the dysregulation of protein synthesis is an essential biochemical event of hepatocyte injury induced by treatment of rats with galactosamine as well as CCl4.
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PMID:Dysregulation of protein synthesis in injured liver. A comparative study on microsomal and cytosole enzyme activities, microsomal lipoperoxidation and polysomal pattern in D-galactosamine and carbon tetrachloride-injured livers. 71 Mar 83

The D-glucose anomeric preference of hexokinases isolated from rat liver, brain, and skeletal muscle, and bovine retina was studied using the glucose-6-phosphate dehydrogenase-NADP system. The ratios of maximum phosphorylation rates of beta-D-glucose to those of alpha-D-glucose were 1.33, 1.46, and 1.54 for hexokinase types I, II, and III from rat liver, 1.45 and 1.63 for type I from rat brain and bovine retina, 1.53 for type II from rat skeletal muscle, and 0.55 (when determined at 5 mM) for type IV (glucokinase) from rat liver, respectively.
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PMID:D-Glucose anomeric preference of hexokinases in higher animals. 71 11

The ratios of some key enzymatic activities of carbohydrate metabolism have been measured in human tumor cytosols. The activities of whole hexokinase (low Km, EC 2.7.1.1 and high Km, EC 2.7.1.2), 6-phosphogluconate dehydrogenase (EC 1.1.1.43), glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and glucose-6-phosphate isomerase (EC 5.3.1.9) change according to a biochemical pattern coherent with cell growth requirements. 6-phosphogluconate dehydrogenase activity was in each sample tested higher than glucose-6-phosphate dehydrogenase activity; this indicates that 6-phosphogluconate, a powerful inhibitor of glucose-6-phosphate isomerase, is unlikely to accumulate and inhibit this enzyme and glucose-6-phosphate channelling into glycolysis.
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PMID:6-phosphogluconate dehydrogenase, glucose-6-phosphate dehydrogenase, glucose-6-phosphate isomerase, and hexokinase activity ratios in some human tumor cytosols. 74 21

Detailed histochemical studies have been conducted on the distribution of hexokinase, amylophosphorylase, aldolase, lactic dehydrogenase, succinic dehydrogenase and glucose-6-phosphate dehydrogenase in every component of the locus ceruleus, nucleus tractus mesencephalicus n. trigemini, nucleus dorsalis n. vagi and nucleus n. hypoglossi of the wistar strain rats. The locus ceruleus and nucleus dorsalis n. vagi which are considered to be belong to "exceptional nuclei" showed mild activity in the nerve cell bodies and strong activity in the surrounding glia cell for the hexokinase reaction. But, the nucleus tractus mesencephalicus n. trigemini and nucleus n. hypoglossi considered to be "usual nuclei" revealed strong activity in the nerve cell bodies and glia cells for the hexokinase reaction, however, glia cells did not show the tendency to surround the nerve cells in these nuclei. On the basis of the present findings, the glia cells may get their energy source from glucose in the circulating blood, and they may be energy donators to the nerve cells in the "exceptional nuclei" whereas the nerve cells may get their energy source directly from glucose in the circulating blood in the "usual nuclei". The former 2 nuclei showed low level activity of succinic dehydrogenase. These findings may indicate that the locus ceruleus and nucleus dorsalis n. vagi belong to the conception "exceptional nuclei" in this respect. However, the Embden-Meyerhof-Parnas (EMP) pathway was dominant in the locus ceruleus, while the WARBURG-DICKENS pathway (hexose monophosphate shunt = HMP shunt) was dominant in the nucleus dorsalis n. vagi in the present study. This descrepancy may strongly suggest that the locus ceruleus is distinctly different from the nucleus dorsalis n. vagi concerning the carbohydrate metabolism, though both nuclei are involved on the same conception "exceptional nuclei". The latter 2 nuclei (the nucleus tractus mesencephalicus n. trigemini and the nucleus n. hypoglossi) considered to be "usual nuclei" in 3 ways as that nerve cells get energy source directly from glucose in the circulating blood, that the 2 nuclei are equipped with enzymes involved in the EMP pathway and the HMP shunt to the same degree, and that they are rich in the tricarboxylic acid (TCA) cycle. The nucleus tractus mesencephalicus n. trigemini revealed considerably variable reactions for the hexokinase, aldolase, glucose-6-phosphate dehydrogenase and lactic dehydrogenase in the present study.
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PMID:Histochemical studies on the distribution of some enzymes concerned with carbohydrate metabolism in the locus ceruleus, nucleus tractus mesencephalicus n. trigemini, nucleus dorsalis n. vagi and nucleus n. hypoglossi of the rat. 80 76

Haemoglobin fractions and 16 enzymatic activities of red cells of a patient with juvenile chronic myeloid leukaemia are compared to normal, to comparably reticulocyte-rich, non-neonatal and to fetal red cells. The activities of hexokinase, triosephosphate isomerase, glyceraldehyde-3-phosphate dehydrogenase, monophosphoglyceromutase, enolase and glucose-6-phosphate dehydrogenase are significantly increased in fetal red cells beyond the activities of cell populations with comparable reticulocytosis. The activities of these enzymes are also increased in the patient's erythrocytes. Together with a haemoglobin F concentration of 54% and a concentration of haemoglobin Bart's of 1% these variations reflect the fetal nature of the red cells. Simultaneously, signs of dyserythropoiesis are found in the red cells of the patient: a very high activity of hexokinase and a low pyruvate kinase activity.
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PMID:Fetal erythropoiesis and dyserythropoiesis in juvenile chronic myeloid leukaemia. 82 74

Glucose turnover was measured in normal and disbetic dogs by the dilution of glucose-1-13C and glucose-1-14C tracers infused simultaneously at constant rates. In order to quantify the stable isotope, an enzymatic assay for the analysis of glucose-1-13C was developed and evaluated. CO2 from C-1 glucose was evolved by coupling hexokinase, glucose-6-phosphate dehydrogenase, and 6-phosphogluconic dehydrogenase activities. The 13C/12C ratio of the CO2 was measured with a high-precision magnetic-deflection double-collector mass spectrometer, and the radioactivity of 14CO2 was quantified by liquid scintillation. The ratio of 13C/12C was reproducible in assays of CO2 evolved from either naturally occurring or 13C-enriched glucose. Furthermore, systemic glucose production rates measured with 13C- and 14C-labeled tracers were similar over a wide range from 2 to 12 mg./kg.-min. Thus, glucose-1-13C may be employed as a tracer for glucose metabolism in human subjects without incurring the risk of radiation.
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PMID:Estimation of glucose turnover with stable tracer glucose-1-13C. 83 67


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