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)

The effect of complete subphrenic vagotomy and simultaneous pyloromyotomy on the morphological state and the activities of some intracellular enzymes of the albino rat was studied histochemically. Within the first weeks after vagotomy, the pancreatic acini were found to diminish in size, and the beta-cells in the islets of Langerhans became oedematous. In the acini, the activities of succinate dehydrogenase, cytochrome oxidase, AS naphthol acetate esterase, and glucose-6-phosphatase were observed to decline, but the reactions for beta-glucuronidase and aryl sulphatase showed intensifications and polymorphic behaviour both in acinar and in islet cells. The latter also and particularly the beta-cells simultaneously revealed enhanced activities of succinate dehydrogenase, cytochrome oxidase, beta-glucuronidase, and aryl sulphatase, and an entire disappearance of the reaction for glucose-6-phosphatase. The alpha-cells increased their AS naphthol acetate esterase activity. After 5 weeks following vagotomy, morphological and enzymatic changes in the acini and islets were negligible, and after 5 and 9 months no differences were noted between the vagotomized rats and the control animals.
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PMID:Histochemical studies on the albino rat pancreas in different periods following vagotomy and simultaneous pyloromyotomy. 17 15

There are considerable changes in the lactic and pyruvic acid contents and fructoso-1,6-diphosphatase and glucose-6-phosphatase activities in some tissues of newborn and adult guinea pigs and rabbits 24 hours after cortisone-acetate (2 mg per 100 g of body weight) injection. In the newborn animals of both species the hormone causes a decrease in the lactic and pyruvic acid concentrations and an increase in fructoso-1,6-diphosphatase activity when in the adult ones--an increase in the lactic and pyruvic acid levels and in the glucose-6-phosphatase. In the liver and kidney cortex of adult animals as compared to the newborn ones the fructoso-1,6-diphosphatase activity is significantly increased and in other tissues under study it is decreased. Certain species differences in lactic and pyruvic acid contents and in the activities of both enzymes as well as in the character of their changes under cortisone influence are found.
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PMID:[Influence of cortisone on the levels of pyruvic and lactic acids and the activity of the enzymes of gluconeogenesis in the tissues of newborn and adult animals]. 17 63

The gluconeogenic capacity of mammary tissue of lactating cow was investigated by incubating mammary tissue slices with alanine, glutamate, lactate, pyruvate, or glycerol in conjunction with acetate and glucose (10mM or 1 mM). In no case was any substrate incorporated into glucose per se. In lactose synthesis, glucose was the major source of carbon although glycerol also was incorporated into lactose. Alanine, glutamate, lactate, or pyruvate were not incorporated into lactose at optimum (10 mM) or suboptimum (1 mM) concentrations of glucose. Activity of glucose-6-phosphatase was negligible in mammary tissue, less than 1% of the activity in liver or kidney tissue from the same cows. Pyruvate carboxylase, phosphoenolpyruvate carboxykinase, and fructose-1,6-diphosphatase were in cow mammary tissue, but the activities were lower than in liver. Gluconeogenic substrates were not converted to glucose regardless of whether the incubation contained an optimum (10 mM) or a suboptimum (1 mM) glucose concentration. Consistent with the inability of cow mammary tissue to convert gluconeogenic metabolites to glucose is the virtual absence of glucose-6-phosphatase and the lack of excess gluconeogenic substrates available to the intact mammary gland of lactating cow.
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PMID:Cellular gluconeogenesis by lactating bovine mammary tissue. 17 3

A method is described for the incorporation of a microsomal rat liver fraction into polyacrylamide films without significant loss of its glucose-6-phosphatase activity. The enzymatic activity was completely lost when the films were prepared with ammonium persulfate as initiator of the polymerization as previously described for alkaline phosphatase, but modification of this method showed that about 90% of the glucose-6-phosphatase activity could be retained. The enzyme in the films prepared with the new method was completely inhibited by alloxan, HgCl2, and preincubation in 0.05 M acetate buffer (pH 5.0) at 37 degrees C, as determined biochemically. Similar results were obtained for the enzyme in films determined histochemically according to the lead method of Wachstein and Meisel. In this respect the behavior of the incorporated enzyme is similar to that in suspension. Films fixed with 1.5% glutaraldehyde showed rapid inactivation of glucose-6-phosphatase. There was good correlation between the biochemical and histochemical activity determined after fixation. A method to embed polyacrylamide films in Epon for electron-microscopical investigation is also described. Dimethyl sulfoxide was used as the dehydrating agent instead of ethanol/acetone.
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PMID:Cytochemical model system for microsomal rat liver glucose-6-phosphate. 18 Jan 74

When lead acetate was administered intraperitoneally to young rats at a dose of 20 mg/kg (five times a week for 6 weeks), their growth rate was retarded when compared with controls injected with sodium acetate. Only a small amount of the heavy metal reached the circulation and exerted limited effects on typical target organs. However, large, electron-dense inclusion bodies were found in the abdominal cavity. The in vivo intestinal absorption of glucose was reduced. When perfused at 40 mM concentration, the experimental animals had a mean absorption rate of 152.1 nmol/min . cm vs. 230.6 in the controls (p less than 0.01). Also, sodium and potassium transport was reduced. No effects were observed on amino acid transport and (Na+-K+)-ATPase. Mg++-ATPase, glucose-6-phosphatase, fructose-1, 6-diphosphatase, pyruvate kinase, succinic dehydrogenase, and tryptophan hydroxylase in the small intestinal mucosa and the kidney were unaltered. Renal alkaline phosphatase was decreased. These studies confirm the greater susceptibility of some active transport mechanisms of the small intestinal mucosa to lead toxicity, compared to those of the kidney.
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PMID:Alterations of intestinal and renal functions in rats after intraperitoneal injections of lead acetate. 46 71

The free and unprecipitated activity of succindehydrogenase and glucose-6-phosphatase, as well as of that of glucose-6-phosphate-dehydrogenase in the rats liver was determined. The animals received for a long time (1--3 and 6 months) a new organophosphorus pesticide valexon (0.0-diethyl thiophosphoryl-oxyiminophenylnitryle acetate) by mouth in doses of 31 mg/kg and 3.1 mg/kg which corresponds to 1/20 and 1/200 LD50. The earliest changes (after 1 month) include: falling activity of hexokinase and a rise in that of glucose-6-phosphatase and succindehydrogenase, pointing to the damage of microsomes and mitochondria supervenes in 1 and 6 months time after introduction, respectively. The role of an early injury of microsomes and of disturbed first stages of glucose metabolism in the mechanism of the valexon action is suggested.
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PMID:[Activity of the indicator enzymes of liver subcellular structures with the prolonged administration of Valexon]. 71 33

The interaction between amphetamine and synthetic oral contraceptive steroids have been studied in the female rat. A progestational agent, quingestanol acetate, and a standard combination contraceptive (quingestanol acetate/ethynyl estradiol) were given with and without the concurrent administration of amphetamine. Steroid treatments increased the activity of some drug-metabolizing enzymes (aminopyrine N-demethylase, coumarin 3- hydroxylase, hexobarbital oxidase). Other parameters measured remained unaltered (glucose-6-phosphatase, aniline hydroxylase, cytochrome c reductase, cytochrome P 450, microsomal protein and phospholipid contents). Amphetamine treatment alone raised some drug-metabolizing enzymes (coumarin 3-hydroxylase, hexobarbital oxidase), increased microsomal phospholipid content and de novo synthesis, but elicited no effect on other enzymes measured. Amphetamine and quingestanol acetate given together significantly increased some drug metabolizing enzymes while the simultaneous treatment with combined steroids and amphetamine showed the most pronounced action. These experiments thus revealed that at least in the liver of the female rat, amphetamine elicited no overt hepatotoxicity, rather, brought about a weak inductive action of drug metabolizing enzymes. The application of steroid hormones also raised drug metabolism and the interaction between amphetamine and contraceptive steroids showed additive effects.
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PMID:Influence of oral contraceptives on the acute effect of amphetamine on the hepatic endoplasmic reticulum of the rat. 84 78

The purpose of this study was to determine the effect of the dietary antioxidant vitamin E on hepatocarcinogenesis by peroxisome proliferators which, it is hypothesized, induce tumors by increased production of hydrogen peroxide or other oxygen radicals. Rats were fed diets containing the peroxisome proliferator ciprofibrate and one of three concentrations (10, 50, or 500 ppm) of alpha-tocopheryl acetate for 6 months or 21 months. The incidence of hepatic tumors and the number and volume of gamma-glutamyl-transpeptidase-positive, ATPase-negative, glucose-6-phosphatase-negative, and glucose-6-phosphatase-positive foci were quantified. No tumors or altered hepatic foci were seen at 6 months, but at 21 months the incidence of hepatic tumors and the number and volume of altered hepatic foci were increased in rats fed higher levels of vitamin E. Indices of oxidative damage--concentrations of malonaldehyde, conjugated dienes, and lipid-soluble fluorescence products--were not affected or were lower in rats fed higher amounts of vitamin E; the enhancing effect of vitamin E on the development of altered hepatic foci and hepatic tumors, therefore, was not related to the induction of cellular oxidative damage. Hepatic peroxisomal fatty acid beta-oxidation and vitamin C concentrations were not affected by vitamin E, whereas the glutathione concentration was decreased in rats fed higher amounts of vitamin E. This study shows that increasing the vitamin E content of the diet enhances ciprofibrate-induced hepatocarcinogenesis, but the mechanism of this effect is unclear.
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PMID:Effect of dietary vitamin E on the development of altered hepatic foci and hepatic tumors induced by the peroxisome proliferator ciprofibrate. 197 53

The livers of streptozotocin-induced diabetic and fasted rats showed a decreased cholesterol synthesis measured by in vitro incorporation of [2-14C]acetate. A significant decrease of glucose-6-phosphate dehydrogenase (G-6-PD), 6-phosphogluconate dehydrogenase (6-PGD), and pyruvate kinase (PK) was also observed 7 days after administration of streptozotocin. These enzymatic activities were also low in livers of 72 hr fasted animals. An increase of glucose-6-phosphatase (G-6-Pase) was observed consistently in diabetic as well as in fasted rats. Suitable amounts of insulin and refeeding normalized the alterated enzymatic activities in diabetic and in fasted animals, respectively.
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PMID:Hexose monophosphate shunt and cholesterol synthesis in the diabetic and fasting states. 299 16

The administration of medroxyprogesterone acetate (MPA) and phenobarbital (PB) improves liver function in rats with liver damage. This was seen here as increased aryl hydrocarbon hydroxylase (AHH) activity after therapy with MPA or PB in rats with a chemical liver injury, produced by dimethylnitrosamine (DMN). Hepatic glucose-6-phosphatase (G6Pase) activity, an index of glucose metabolism was also normalized in the MPA treated rats. The present study further shows that MPA induced hepatic malic enzyme (ME) and isocitrate dehydrogenase (ICDH) activities and PB enhanced glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH) and ME activities in the DMN pretreated rats. This suggests that MPA and PB enhanced the capacity of altered liver tissue to generate NADPH, a cofactor in the monooxygenase system, which may, in part, enhance the restoration of drug hydroxylation in the rats. Since G6PDH, 6PGDH and ME participate in glucose metabolism, the finding that the compounds influenced these enzymes in distinct ways, may explain the different effects of MPA and PB on the restoration of glucose metabolism.
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PMID:Medroxyprogesterone acetate and phenobarbital induce NADPH producing enzyme activities in rats with a chemical liver injury. 300 83


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