Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.9 (glucose-6-phosphatase)
 3,081 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Differential centrifugation was applied to adult and foetal liver of monkey. Obtained fractions were: F1 (800 X g); F2 (12 500 X g); F3 (200 000 X g); and cell sap. Analysis of chemical compounds of these fractions shows that: (1) adult and foetal nucleic acids levels are similar; (2) there are more proteins in adult than in foetal hepatocytes; (3) most of the glycogen is located in F3; the foetal level is twenty times higher than the adult level. Plasma membrane enzymes (5'-nucleotidase, adenylate cyclase) show a nucleomicrosomic distribution. The distribution of alkaline phosphatase is not significant. Mitochondrial enzymes (monoamine oxydase, succinate cytochrome c reductase, cytochrome oxydase) are enriched in F2 without any sedimentation in F3. There is more malate dehydrogenase liberated in cell sap during foetal liver fractionation. This indicates the foetal mitochondria are more sensitive to the homogenisation method. Lysosomal enzymes (acid phosphatase, N-acetylglucosaminidase) are enriched in F2. The same observation for N-acetylglucosaminidase as for malate dehydrogenase leads to the same conclusion for foetal lysosomes. Endoplasmic reticulum and Golgi enzymes (glucose-6-phosphatase and related phosphotransferase activity, NADPH-cytochrome c reductase and sialytransferase) are much enriched in F3. Thus this fraction F3 is pure enough to allow the observation of the modification produced on endoplasmic reticulum and Golgi apparatus during foetal and neonatal development.
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PMID:[Comparative study of microsomal enzymic activities in adult and foetal monkey hepatocytes (author's transl)]. 11 30

1. Cataract formation in streptozotocin-induced diabetes in rats was reduced by approximately 85% when a diet rich in maize oil (300 g/kg diet) (fat diet) was given, thus confirming results of earlier studies. However, the concentration of sorbitol in the lens of diabetic animals remained high, the values for diabetic rats given the standard diet and the fat died being 65 and 40 mumol/g protein respectively. 2. With the standard diet, the fatty acid profile of the triglycerides of the epididymal fat pads was characterized by a greater relative proportion of saturated fatty acids for the diabetic animals compared to that for the normal animals. The fat diet moderated the tendency towards saturation in the diabetic animals. 3. The fat diet had other effects on the diabetic animals; these included a reduced mortality rate, increased body-weight, a decrease in the daily water intake, and in the daily urinary excretion of glucose and urea. 4. In the diabetic animals the fat diet had no effect on the specific activities in the liver of hexokinase (EC 2.7.1.1), glucokinase (EC 2.7.1.2), phosphofructokinase (EC 2.7.1.11) and pyruvate kinase (EC 2.7.1.40). However, the specific activity of glucose-6-phosphatase (EC 3.1.3.9) was reduced, while that of malate dehydrogenase (decarboxylating) (NADP) (EC 1.1.1.40) was increased. The NAD+:NADH ratio, as calculated from liver pyruvate and lactate concentrations, tended to increase. 5. The results suggested that the fat diet moderated the long-term metabolic effects of diabetes.
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PMID:The effect of an unsaturated-fat diet on cataract formation in streptozotocin-induced diabetic rats. 13 11

In the presented study the influence of freezing and freeze-drying on enzyme activity is described. Attention is paid to 16 enzymes which can be used for quantitative enzyme histochemical techniques. With the exception of succinate dehydrogenase only, no significant inactivation during freezing and freeze-drying procedures could be demonstrated with lactate dehydrogenase, malate dehydrogenase (NAD+), malate dehydrogenase (decarboxylating) (NADP+), isocitrate dehydrogenase (NADP+), glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, NADH-oxydoreductase, mitochondrial glycerol-3-phosphate dehydrogenase, cytochrome c oxidase, phosphoglucomutase, glucosephosphate isomerase, glucose-6-phosphatase, acid phosphatase, beta-glucuronidase and non specific aryl esterase. Therefore, the results supply a sound foundation for those quantitative enzyme histochemical techniques in which tissue specimens are frozen or frozen-dried before enzyme estimations are performed.
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PMID:The influence of freezing and freeze-drying of tissue specimens on enzyme activity. 87 Apr 61

The effect of Fusarium sporotrichiella v. sporotrichioides mycotoxin (sporofusarin) on the total and non-sedimentary supernatant activity of 13 marker-enzymes of subcellular particles (2 mitochondrial enzymes-cytochrome oxidase and malate dehydrogenase; 8 lysosomal enzymes -- acid phosphatase, acid RNAase, acid DNAase, arylsulphatases A and B, beta-N-acetylglucosaminidase, beta-glucuronidase, beta-galactosidase and beta-glucosidase; 2 microsomal enzymes -- glucose-6-phosphatase and acetylesterase; plasma membrane enzyme -- alkaline phosphatase) of the rat liver, kidney, spleen and bone-marrow was studied in in vivo experiments. The latter demonstrated that sporofusarin effects were characterized by a significant organ and organella specificity, viz. the toxin caused a sharply increased activity, mainly of lysosomes enzymes and labilization of the lysosomal membranes, primarily in the spleen and the bone-marrow. A conclusion is drawn that the discovered selective destructive action of sporofusarin on the lysosomes may be regarded as a new phenomenon that, possibly is directly related to the characterization of the mechanism responsible for a specific effect produced by sporofusarin.
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PMID:[Lysosomal component in the mechanism of the toxic effect of sporofusarin]. 94 27

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

In vitro rates of lactate conversion to glucose and oxidation to CO2 were determined in livers of stress-susceptible (SS) and stress-resistant (SR) pigs because we hypothesized that livers of SS pigs had a lower capacity than livers of SR pigs to remove lactate from blood. Stress-susceptibility was determined by reaction to halothane at 7 weeks of age. At approximately 9 weeks of age, pigs were assigned to one of three experimental diets. Pigs weighing 95 kg were slaughtered immediately after stress, and liver samples were obtained. Incorporation of lactate into glucose in liver of SS pigs was 38% of that in SR pigs. Addition of either vitamin C or vitamins C and E plus magnesium oxide and collagen extract to a corn-soy diet did not alter lactate conversion to glucose, but depressed lactate oxidation to CO2. No differences were detected in either activities of lactate dehydrogenase, HAD-malate dehydrogenase, phosphoenolpyruvate carboxykinase, fructose-1,6-diphosphatase, and glucose-6-phosphatase or concentration of glycogen in livers of SS and SR pigs. Our data indicate that livers of SS pigs possess a lower capacity to incorporate lactate into glucose and to oxidize lactate to CO2; maximal activities of enzymes measured in this study are not the cause of these differences. Reduced capacity of lactate metabolism in livers of SS pigs seems a part of the etiology of the porcine stress syndrome.
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PMID:Gluconeogenesis from lactate in liver of stress-susceptible and stress-resistant pigs. 126 79

Renal clear cell tubules and clear/acidophilic cell tumors were induced in male Sprague-Dawley rats by 7 weeks oral administration (stop model) of N-nitrosomorpholine (NNM) at a concentration of 12 mg/100 ml in the drinking water. Twelve, 23 and 34 weeks after withdrawal of NNM serial cryostat sections of the kidneys were histochemically analyzed for the following parameters: glucose transporter proteins (GLUT1, GLUT2), glycogen content and the activities of glycogen synthase (SYN), glycogen phosphorylase (PHO), glucose-6-phosphatase (G6Pase), glucose-6-phosphate dehydrogenase (G6PDH), hexokinase (HK), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate kinase (PK), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), alkaline phosphatase (ALP), acid phosphatase (ACP) and gamma-glutamyltransferase (GGT). Clear cell (glycogenotic) tubules first appeared at 23 weeks, and clear/acidophilic cell tumors at 34 weeks after withdrawal of the carcinogen. G6Pase, ALP, GGT and GLUT2 were absent in clear cell tubules, clear/acidophilic cell tubules, and clear/acidophilic cell tumors indicating a sequential origin of all these types of lesions from the collecting duct system, in line with previous morphological findings. In comparison to the collecting duct epithelium, glycogenotic tubules demonstrated an increased activity of PHO and reduced activities of glycolytic and mitochondrial enzymes, which were accompanied by a strongly reduced expression of GLUT1. Moderately increased activities of glycolytic and mitochondrial enzymes were observed in the clear cells of clear/acidophilic cell tubules and tumors compared with those in glycogenotic tubules. They had slightly increased activities of the glycolytic enzymes GAPDH and PK compared with normal collecting duct epithelium, while most of them were nearly lacking in GLUT1. Our findings suggest that glycogen storage is not due to an increased uptake of glucose from the blood, but results from a disturbance in intracellular flux of metabolites. The development of clear cell tubules from the normal collecting duct epithelium is accompanied by a markedly decreased expression of GLUT1 along with a reduction in glycolytic and mitochondrial enzymes. This reduction of enzyme activities is replaced by an increase in enzyme activities in clear/acidophilic cell tumors indicating a fundamental shift in carbohydrate metabolism during progression from preneoplastic to neoplastic lesions.
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PMID:Sequential changes in glycogen content, expression of glucose transporters and enzymic patterns during development of clear/acidophilic cell tumors in rat kidney. 147 41

Chronic infection of woodchucks with woodchuck hepatitis virus (WHV) was associated with the development of hepatitis, foci of altered hepatocytes and hepatocellular adenomas and carcinomas. The cytomorphological and cytochemical analysis permitted the identification of three different types of focal lesions; namely, glycogen-storage foci, mixed-cell foci and intermediate-cell foci, each showing a characteristic pattern. The cells of the glycogen-storage foci had clear to acidophilic cytoplasm, and were overloaded with glycogen. They showed a marked elevation in the activity of glucose-6-phosphate dehydrogenase (G6PDH) and malate dehydrogenase (MDH), increased activity of succinate dehydrogenase (SDH), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and glycerol-3-phosphate dehydrogenase (G3PDH), reduction in the activity of glycogen phosphorylase (PHO), glucose-6-phosphatase (G6Pase), adenosine triphosphatase (ATPase) and adenyl cyclase (ADC), and unchanged activity of glycogen synthase (SYN) and gamma-glutamyl transferase (GGT). The mixed-cell foci mainly consisted of basophilic cells poor in glycogen, but were intermingled with cells containing glycogen. These foci were characterized by a marked decrease in activity of PHO, SYN, G6Pase, G6PDH, ATPase and ADC, and increased activity of GGT, SDH, MDH and GAPDH. The intermediate-cell foci consisted of cells with both basophilic and glycogenotic cytoplasmic compartments, and showed a similar enzyme histochemical profile to the mixed-cell foci, with slight differences in the degree of elevation or reduction of some enzymes. The phenotypic similarities and the close spatial relationship between the foci of altered hepatocytes, and the hepatocellular adenomas and carcinomas in WHV-infected woodchucks, suggest that these lesions are preneoplastic. The focal morphological and metabolic aberrations emerging during hepatocarcinogenesis in WHV-infected woodchuck, are in principle similar to those identified in the course of chemical hepatocarcinogenesis in various species. The focal metabolic aberrations apparently represent a general biological response of the liver parenchyma to oncogenic agents and are closely linked to neoplastic transformation of the hepatocytes.
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PMID:Phenotypic patterns of preneoplastic and neoplastic hepatic lesions in woodchucks infected with woodchuck hepatitis virus. 215 41

Enzyme histochemical methods were performed on sporozoite infected liver tissue of rats in order to gain insight into the nutrition and metabolism of exoerythrocytic forms of Plasmodium berghei. The following enzymes were demonstrated in the hepatocytic stages of the parasites, obtained 41 and 48 h after inoculation of sporozoites: acid phosphatase, cytochrome oxidase, NADH-tetrazolium reductase, succinate dehydrogenase, NAD+ and NADP+ dependent isocitrate dehydrogenase, NADP+-dependent malate dehydrogenase, lactate dehydrogenases, 6-phosphogluconate dehydrogenase and glucose-6-phosphate dehydrogenases and alpha-glycerol-phosphate dehydrogenase. The results suggest that a conventional Embden-Meyerhoff pathway, pentose phosphate pathway and Krebs' citric acid cycle may in part be present in these exoerythrocytic parasites. Alkaline phosphatase, nucleoside polyphosphatase, 5' nucleotidase, glucose-6-phosphatase, alpha-glucan phosphorylase, NAD+ dependent malate dehydrogenase, amino-peptidase M and non-specific esterases were not detected by our techniques in the parasite. The enzyme distribution of this intrahepatocytic malaria parasite revealed by histochemistry is compared with the enzyme distribution in the other phases of the parasite's life cycle.
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PMID:Histochemical observations on the exoerythrocytic malaria parasite Plasmodium berghei in rat liver. 608 94

The freshwater murrel, Channa punctatus, was exposed to a sublethal concentration of mercuric chloride (3 micrograms/liter) for 120 days and the following effects were examined: changes in the levels of glucose and lactic acid in blood and of glycogen and lactic acid in liver and muscles; rate of absorption of glucose from the intestine; and changes in the activities of glucose-6-phosphatase (G-6-Pase), hexokinase, lactate dehydrogenase (LDH), pyruvate dehydrogenase (PDH), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), glutamate dehydrogenase (GDH), L-amino acid oxidase (AO), and xanthine oxidase (XO) in brain, gills, intestine, kidney, liver, and muscles. Mercury-treated fish were hypoglycemic and hypolactemic. The glycogen content of liver and muscles remained unaltered but the muscle lactic acid level decreased significantly. The rate of intestinal absorption of glucose was reduced significantly by exposure to mercury. G-6-Pase activity was decreased in all the tissues. Hexokinase activity also decreased in mercury-exposed fish but it was significant only in intestine, kidney, and liver. The activities of LDH, PDH, SDH, and MDH also were decreased significantly except LDH in brain and MDH in kidney where an insignificant decrease and an insignificant increase, respectively, were recorded. GDH and AO activities were elevated in most of the tissues except GDH in gills, and AO in gills and muscles where a decrease was observed. XO activity in brain, gills, and kidneys was significantly elevated, but no marked alteration was noted in other tissues.
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PMID:Effect of mercuric chloride on some biochemical and physiological parameters of the freshwater murrel, Channa punctatus. 608 7


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