Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.4.3.11 (glutamate dehydrogenase)
 4,437 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A histochemical evaluation of the activity of chosen oxido-reductive enzymes of the cardiac muscle connected with the citric acid cycle, glycolysis and pentose shunt in the early experimental alloxan diabetes period in white rats has been carried out. Dehydrogenases: succinate, isocitrate and glucose-6-phosphate indicated a decrease in the enzymatic activity while the lactate dehydrogenase activity did not undergo any change. An increase in the intensity of the histoenzymatic reaction only concerned glutamate dehydrogenase. The presented histoenzymatic evidence of changes in the enzymatic activities may speak for the possibility of an existence of a direct diabetes influence on the cardiac muscle metabolism.
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PMID:Some histochemical observations on the myocardial metabolism in experimental conditions. Part II. 9 52

Posthepatectomy coma was produced in 13 dogs and the cerebrums were biopsied for analysis of concentrations of glucose, glucose-6-phosphate, dihydroxyacetone-phosphate, phosphoenolpyruvate, pyruvate, lactate, citrate, alpha-ketogulutarate, fumarate, malate, oxaloacetate, adenosinetriphosphate, ammonia, and glutamine as well as for activities of glucokinase, phosphofructokinase, pyruvate kinase, isocitrate dehydrogenase, glutamate dehydrogenase, malate dehydrogenase, and malic enzyme. There were no differences from normal in the brain glycolytic substrate concentrations. Four of the Krebs cycle substrates were significantly reduced, but not differently than in dogs sedated for 24 hours. The glycolytic pathway, Krebs cycle, and related enzyme activities were not significantly altered. Cerebral adenosine triphosphate concentration was unchanged but the concentrations of ammonia and glutamine increased threefold.
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PMID:Effect of total hepatectomy on selected cerebral substrates and enzymes of the glycolytic pathways and Krebs cycle. 17 Jun 98

Histochemical studies of some myocardial oxido--reductive enzymes after a beta--adrenergic blockade with propranolol have been carried out. Succinate, isocitrate and glucose-6-phosphate dehydrogenases did not indicate any changes in activity, whereas the changes in reaction intensities concerning NADH and NADPH tetrazole reductases and glutamate dehydrogenase have rather a transitory and reversible character. Only lactate dehydrogenase showed an increase in the enzymatic activity which speaks for an increase in the glycolysis process in the heart muscle. In the light of our own presented research results we assume that the experimental beta--adrenergic blockade of the heart muscle in rats does not evoke more important enzymatic changes which are noticeable in histochemical microscope examination.
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PMID:Histochemical studies of some myocardial oxido-reductive enzymes after experimental beta-adrenergic blockade with propranolol. 21 81

In the subcommissural organ (SCO) of the guinea pig, rat, golden hamster, and mouse the activity and distribution of enzymes related to the energy-supplying metabolism and of some marker enzymes of different cell organelles have been investigated by means of mostly modified histochemical methods. The results were compared with findings in the ciliated ependyma of the ventricular wall and with those in the ependyma of the choroid plexus of the third ventricle. In the ependymal part of the SCO only a moderate activity of hexokinase is observed in its specialized columnar cells whereas a high activity is present both in the ciliated ependyma and the choroid plexus. - The staining pattern of glucose-6-phosphatase is similar to that of hexokinase but this enzyme is found is the SCO only. - Likewise hexokinase, glycogen granules and enzymes related to glycogen metabolism (phosphoglucomutase, uridine-diphosphoglucose pyrophosphorylase, glycogen synthetase and phosphorylase) are regularly found most numerous and active in the nuclear and supra-nuclear area of the ependymal part. These enzymes are less active in both the other ependymal regions. - Uridine-diphosphoglucose dehydrogenase could not be demonstrated in the SCO. The NADP-linked enzymes of the pentose phosphate shunt, glucose-6-phosphate and 6-phosphogluconate dehydrogenase, show a moderate activity which decreases also from the nuclear towards the apical area of the ependymal cells of the SCO. Enzymes of the glycolytic pathway, such as glucosephosphate isomerase, fructose-6-phosphate kinase, fructose-I,6-diphosphate aldolase, glyceraldehyde-3-phosphate and lactate dehydrogenase, are highly active in the SCO and are located mainly in the supranuclear area, too. Fructose-1,6-diphosphatase could not be demonstrated thus indicating that in the SCO the pathway is most probably only glycolytic but not gluconeogenetic. Compared to the ependyma of the ventricular wall and of the choroid plexus, in the SCO the M type subunits of lactate dehydrogenase predominate. Glycolytic enzymes are also very active in the choroid plexus but less in the ciliated ependyma. Compared to the ciliated ependyma and especially to the ependyma of the choroid plexus, the activities of enzymes which are only present in mitochondria (NAD-linked isocitrate dehydrogenase, succinate dehydrogenase, NAD-linked malate dehydrogenase after preextraction, cytochrome oxidase, 3-hydroxybutyrate and glycerolphosphate and glutamate dehydrogenase) are relatively low. Mitochondria are accumulated near the superior pole of the nuclei as well as in the most apical part of the ependymal cells. - The staining pattern of NADP-linked isocitrate and malate dehydrogenase as well as of NADH dehydrogenase suggests that these enzymes are localized both in and out of mitochondria. The extramitochondrial activity of the first two enzymes might be localized in the cytosol. The extramitochondrial activity of NADH dehydrogenase might be localized in the endoplasmic reticulum...
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PMID:Enzymatic organization of the subcommissural organ. 123 49

Cytochemical methods for the demonstration of enzyme activities in blood and bone marrow cells were systematically improved by the addition of an inert polymer, polyvinyl alcohol (PVA), to the incubation medium and by using optimized reaction media. The methods investigated were tetrazolium salt methods for lactate, glucose-6-phosphate, succinate and glutamate dehydrogenase, the indoxyl-tetrazolium salt method for alkaline phosphatase, the diaminobenzidine method for peroxidase, and diazonium salt methods for chloroacetate esterase, beta-glucosaminidase, beta-glucuronidase, acid phosphatase, and dipeptidylpeptidase II and IV. PVA in the media preserved the morphology of cells very well and prevented leakage of large molecules such as enzymes from the cells. Therefore, fixation or long periods of air-drying prior to incubation leading to substantial loss of enzyme activity could be avoided. A brief period of drying (2 min at 37 degrees C) of the cell preparations just before the incubation was sufficient for making the cells permeable. Localization of enzyme activities was very precise and precipitation of the final reaction product was confined to sites which are known to contain the enzyme under study (granules, mitochondria, lysosomes). These advantages advocate the use of PVA in haematological enzyme cytochemistry and especially for diagnosis of leukemia.
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PMID:Enzyme cytochemistry of unfixed leukocytes and bone marrow cells using polyvinyl alcohol for the diagnosis of leukemia. 280 89

The effects of different cerebro-protective agents on selected key enzymes of the energy metabolism of rat primary glial cultures and rat cerebral cortex were studied. As indicators for the capacity of the most important pathways of energy metabolism the following enzyme activities were determined: hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G-6-P-DH), malate dehydrogenase (MDH), glutamate dehydrogenase (GDH), and cytochrome-c-reductase (CCR). After a one week growth period, rat glial cultures were incubated for 3 or 4 weeks with the substances to be tested. Bencyclane (5 X 10(-5) mol/l) increased the activities of HK, G-6-P-DH, and LDH, whereas PFK and CCR were reduced. Pyritinol (10(-4) mol/l) led to a higher G-6-P-DH activity, simultaneously lowering the values for PFK, CCR, PK, LDH, and MDH. Under the influence of an extract of the leaves of Ginkgo bilobae (EGB; 100 mg/l) PFK, LDH, and MDH activities were reduced. All these alterations in enzyme activities went along with simultaneous reductions in protein content, therefore not allowing to exclude toxic effects with regard to the doses used. Moreover, direct interference with the analytical procedure was demonstrable for bencyclane and EGB. Piracetam (10(-3) mol/l), flunarizine (10(-6) mol/l), dihydroergocristine (5 X 10(-6) mol/l), and nicergoline (5 X 10(-6) mol/l) failed to induce any alteration in the employed doses. The most striking effects were obtained with meclofenoxate which was tested at 10(-3) and 10(-4) mol/l. The higher dose caused an elevation of HK, PFK, CCR, G-6-P-DH, GDH and MDH activities, while slightly reducing PK. With the lower dose of meclofenoxate CCR and G-6-P-DH activities were increased. Short-term incubation of the cultures with 10(-3) mol/l meclofenoxate for 24 hr led to an increase in LDH, G-6-P-DH, and GDH activities. Chronic incubation with meclofenoxate (10(-3) mol/l) followed by 48 hr deprivation of the drug resulted in elevated HK, PFK, CCR, G-6-P-DH, GDH, and MDH activities. These changes were accompanied by alterations in related metabolite levels. These include elevations in the concentration of creatine phosphate and fructose-1,6-bisphosphate, whereas glucose-6-phosphate levels were reduced. After one week of meclofenoxate deprivation the activities of CCR and G-6-P-DH were still elevated. The metabolites of meclofenoxate dimethylaminoethanol (DMAE; 10(-3) mol/l) and p-chlorophenoxyacetic acid (10(-3) mol/l) were also investigated.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Effects of cerebro-protective agents on enzyme activities of rat primary glial cultures and rat cerebral cortex. 294 86

Chronic metabolic alkalosis was induced in rats drinking 0.3 M NaHCO3 and receiving 1 mg furosemide/100 g body weight per day intraperitoneally. Another group of animals received a potassium supplement in the form of 0.3 M KHCO3. In this group, hypokalemia did not develop and muscle potassium fell by only 18% versus 50% in those not receiving potassium. In vitro renal production of ammonia and uptake of glutamine fell by 40% with a decrease in the activity of glutaminase I and glutamate dehydrogenase. Activity of phosphofructokinase, a major enzyme of glycolysis, rose only in the kidney of animals receiving a potassium supplement. Fructose-1,6-diphosphatase fell as well as phosphoenolpyruvate carboxykinase. Malate dehydrogenase also fell. The activity of phosphofructokinase also rose in the liver, heart, and leg muscle. The major biochemical changes in the renal cortex were the following: glutamate, alpha-ketoglutarate, malate, lactate, pyruvate, alanine, aspartate, and citrate rose as well as calculated oxaloacetate. The concentration of intermediates like 2-phosphoglycerate, 3-phosphoglycerate, and glucose-6-phosphate fell. The cytosolic redox potential (NAD+/NADH) decreased. In addition to the fall in ammoniagenesis, it could be demonstrated in vitro that the renal tubules incubated with glutamine showed decreased glucose production and increased production of lactate and pyruvate. The concentration of lactate was elevated in all tissues examined including liver, heart, and leg muscle. This study confirms in the rat that decreased renal ammoniagenesis takes place following decreased uptake of glutamine in metabolic alkalosis. All other changes are accounted for by the process of increased glycolysis, which appears to take place in all tissues in metabolic alkalosis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Renal tissue metabolism in the rat during chronic metabolic alkalosis: importance of glycolysis. 294 66

In order to study the intracellular localization of the proteolytic processing steps in the maturation of alpha-glucosidase and cathepsin D in cultured human skin fibroblasts we have used incubation with glycyl-L-phenylalanine-beta-naphthylamide (Gly-Phe-NH-Nap) as described by Jadot et al. [Jadot, M., Colmant, C., Wattiaux-de Coninck, S. & Wattiaux, R. (1984) Biochem. J. 219,965-970] for the specific lysis of lysosomes. When a homogenate of fibroblasts was incubated for 20 min with 0.5 mM Gly-Phe-NH-Nap, a substrate for the lysosomal enzyme cathepsin C, the latency of the lysosomal enzymes alpha-glucosidase and beta-hexosaminidase decreased from 75% to 10% and their sedimentability from 75% to 20-30%. In contrast, treatment with Gly-Phe-NH-Nap had no significant effect on the latency of galactosyltransferase, a marker for the Golgi apparatus, and on the sedimentability of glutamate dehydrogenase and catalase, markers for mitochondria and peroxisomes, respectively. The maturation of alpha-glucosidase and cathepsin D in fibroblasts was studied by pulse-labelling with [35S]methionine, immunoprecipitation, polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate and fluorography. When homogenates of labelled fibroblasts were incubated with Gly-Phe-NH-Nap prior to immunoprecipitation, 70-80% of all proteolytically processed forms of metabolically labelled alpha-glucosidase and cathepsin D was recovered in the supernatant. The earliest proteolytic processing steps in the maturation of alpha-glucosidase and cathepsin D appeared to be coupled to their transport to the lysosomes. Although both enzymes are transported via the mannose-6-phosphate-specific transport system, the velocity with which they arrived in the lysosomes was consistently different. Whereas newly synthesized cathepsin D was found in the lysosomes 1 h after synthesis, alpha-glucosidase was detected only after 2-4 h. When a pulse-chase experiment was carried out in the presence of 10 mM NH4Cl there was a complete inhibition of the transport of cathepsin D and a partial inhibition of that of alpha-glucosidase to the lysosomes. Leupeptin, an inhibitor of lysosomal thiol proteinases, had no effect on the transport of labelled alpha-glucosidase to the lysosomes. However, the early processing steps in which the 110-kDa precursor is converted to the 95-kDa intermediate form of the enzyme were delayed, a transient 105-kDa form was observed and the conversion of the 95-kDa intermediate form to the 76-kDa mature form of the enzyme was completely inhibited.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Biosynthesis and intracellular transport of alpha-glucosidase and cathepsin D in normal and mutant human fibroblasts. 390 6

Five enzymes were measured in 50 liver specimens (18 normal liver, 20 Reye liver, 12 diverse liver disorders other than Reye syndrome). The enzymes were: glutamic dehydrogenase (E.C. 1.4.1.3), monoamine oxidase (E.C. 1.4.3.4), lactate dehydrogenase (E.C. 1.1.1.27), D-glucose-6-phosphate dehydrogenase (E.C. 1.1.1.49), catalase (E.C. 1.11.1.6). The Reye syndrome group showed significant decreases in glutamic dehydrogenase (56%) and monoamine oxidase (70%) compared to normal control tissue and these changes were not characteristic of the non-Reye liver disorder group as a whole. Neither catalase nor lactate dehydrogenase appeared to be altered significantly in the Reye or in the abnormal control group compared with normal controls. Thus, only the prominent decreases in the mitochondrial enzyme activities appeared to be highly characteristic of Reye syndrome. Paradoxically, the means of the five hepatic enzymes and the admission levels of two serum enzymes indicative of liver damage (alanine and aspartate aminotransferase) were remarkably similar for both survivors and nonsurvivors of Reye syndrome.
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PMID:Quantitative evaluation of the extent of hepatic enzyme changes in Reye syndrome compared with normal liver or with non-Reye liver disorders: objective criteria for animal models. 396 10

Coenzymic activities of the following NADP derivatives were investigated: 2'-O-(2-carboxyethyl)phosphono-NAD (I), N6-(2-carboxyethyl)-NADP (II), 2'-O-(2-carboxyethyl)phosphono-N6-(2-carboxyethyl)-NAD (III), 2'-O-[N-(2-aminoethyl)carbamoylethyl]phosphono-NAD (IV), N6-[N-(2-aminoethyl)carbamoylethyl]-NADP (Va), 2',3'-cyclic NADP, and 3'-NADP. Derivatives I and IV show the effects of modification at the 2'-phosphate group, and derivatives II and Va show those at the 6-amino group of NADP. As for enzymes, alcohol, isocitrate, 6-phosphogluconate, glucose, glucose-6-phosphate, and glutamate dehydrogenases were used. These enzymes were grouped on the basis of the ratio of the activities for NAD and NADP into NADP-specific enzymes (ratio less than 0.01), NAD(P)-specific enzymes (0.01 less than ratio less than 100), and NAD-specific enzymes (ratio greater than 100). For NADP-specific enzymes, modifications at the 2'-phosphate group of NADP caused great loss of cofactor activity. The relative cofactor activities (NADP = 100%) of derivatives I and IV for these enzymes were 0.5-20 and 0.01-0.5%, respectively. On the other hand, NAD(P)-specific enzymes showed several types of responses to the NADP derivatives. The relative cofactor activities of I and IV for Leuconostoc mesenteroides and Bacillus stearothermophilus glucose-6-phosphate dehydrogenases and beef liver glutamate dehydrogenase were 60-200%; whereas, for B. megaterium glucose dehydrogenase and L. mesenteroides alcohol dehydrogenase, the values were 0.8-8%. For NAD-specific enzymes, these values were 20-50%. The relative cofactor activities of 2',3'-cyclic NADP and 3'-NADP were very low (less than 0.2%) except for beef liver glutamate dehydrogenase, B. stearothermophilus glucose-6-phosphate dehydrogenase, and horse liver alcohol dehydrogenase. Kinetic studies showed that the losses of the cofactor activity of NADP by these modifications were mainly due to the increase of the Km value. The mechanisms of coenzyme specificity of dehydrogenases are discussed. Unlike the 2'-phosphate group, the 6-amino group is common to NAD and NADP, and the effects of modification at the 6-amino group were independent of the coenzyme specificity of enzymes used for the assay. Derivatives II and Va had high relative cofactor activities (65-130%) for most of the enzymes except for isocitrate and glucose dehydrogenases (less than 1%) and L. mesenteroides alcohol dehydrogenase (20-60%). The cofactor activity of derivative III was generally lower than those of I and II.
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PMID:Coenzymic activity of NADP derivatives alkylated at 2'-phosphate and 6-amino groups. 397 81


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