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)

Triphasic changes in glycogen content and activities of four enzymes of carbohydrate metabolism (glucose-6-phosphatase, phosphoenolpyruvate carboxykinase, hexokinase, and glucose-6-phosphate dehydrogenase) were studied in the liver of male Wistar rats exposed to 1, 5, 10, 15, 20, 30, 45, 60, 70 and 90-day movement restrain in pencil cases. It was assumed that these three phases corresponded to the alarm, resistance and exhaustion stages of Selye's general adaptation syndrome. In hypokinetic rats, however, a transition of the alarm reaction to the resistance stage was registered later, and hepatic glycogen accumulation was reduced in comparison with the standard pattern observed in chronic stress.
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PMID:Effect of prolonged restraint on glycogen content and activities of four enzymes of carbohydrate metabolism in the liver of rats. 301 79

Architectural arrangement, ultrastructure, and selected histochemical properties of the newt (Notophthalmus viridescens) liver were examined. Although hematopoietic tissue (1-4 cells thick) invested the liver, direct vascular communication between this tissue and hepatic parenchyma was not observed. The liver was intensely positive when stained with Oil-red-O and periodic acid-Schiff reagent and connective tissue was limited to large vascular channels and the capsule. A distinctive polarity was observed in the hepatic vascular system when lobes were viewed in cross section. Dorsally, portal venules accompanied arterioles and branches of the biliary system, while tributaries of hepatic veins were observed ventrally. Following perfusion fixation, hepatocytes appeared as sheets of cells 1-5 cells thick; however, lobules as defined in adult mammalian liver were absent. Hepatocytes contained abundant smooth endoplasmic reticulum, mitochondria, electron-dense lysosomes, patches of granular endoplasmic reticulum, and lipid droplets. Continuous endothelial cells lined sinusoids and exhibited fenestrae organized into structures similar to sieve plates observed in mammalian liver. Variable numbers of melanin-containing macrophages and subendothelial macrophages were observed; however, Kupffer cells and lipid containing perisinusoidal fat-storing cells were not seen. Patterns of reaction product for glucose-6-phosphatase (G-6-Pase), glucose-6-phosphate dehydrogenase (G-6-PDH), and succinic dehydrogenase (SDH) were localized in the newt liver. All enzymes exhibited a uniform distribution pattern; however, small punctate regions of intensely positive G-6-PDH cells were noted within hepatic parenchyma. Cells comprising the hematopoietic tissue were intensely positive for G-6-Pase, G-6-PHD, and negative for SDH.
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PMID:Morphologic and histochemical analysis of the newt (Notophthalmus viridescens) liver. 303 62

Adenylate cyclase (AC) activity was demonstrated histochemically using adenylate-(beta,gamma-methylene)diphosphate as substrate in cryostat sections of livers from 45 rats treated for 7-10 weeks with N-nitrosomorpholine (NNM) (120 mg/l drinking water) and from nine untreated control rats. The enzyme patterns of normal tissue, preneoplastic and neoplastic lesions were characterized and correlated with the morphologically defined stages of tumour development in the liver. Light microscopically, the enzyme activity of normal tissue was restricted to the plasma membrane, and was most pronounced along the bile canaliculi of the hepatocytes. In glycogen storage foci and mixed cell foci induced by NNM no, or only very weak, AC activity was visible. In the cells of neoplastic nodules and hepatocellular carcinomas AC activity was also clearly reduced. However, in small parts of the plasma membrane which lined lumina resembling normal bile canaliculi and in cytoplasmic vesicles closely associated with these structures, some AC activity was occasionally detected by light and electron microscopy. Whereas the tissue of normal appearance surrounding the lesions showed a marked increase in AC activity in the presence of glucagon, forskolin and cholera toxin. AC activity in the preneoplastic and neoplastic liver lesions could not, or could only weakly, be stimulated by this treatment. As demonstrated in serial sections of the foci, the reduction in AC activity corresponded to changes in the activity of other enzymes studied earlier in the same model. Thus the reduction in AC activity was accompanied by a decrease in the activity of glucose-6-phosphatase and glycogen phosphorylase, and by an increase in the activity of glucose-6-phosphate dehydrogenase. The results support the concept that the focal changes in the activity of many enzymes (including those of carbohydrate metabolism) during hepatocarcinogenesis are the consequence of aberrations in superordinate regulatory mechanisms of cell metabolism.
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PMID:Loss of adenylate cyclase activity in preneoplastic and neoplastic lesions induced in rat liver by N-nitrosomorpholine. 369 88

The effects of high-dose indomethacin (three daily dose, 8.5 mg/kg ip) on pathology and histology, on serum and urine biochemistry, and on various hepatic enzyme activities were studied in rats. Hepatic cytochrome P-450 and aminopyrine N-demethylase were decreased by 52-62%, but glucuronyl transferase fell by only 22%. Hepatic glucose-6-phosphatase, aryl esterase, 6-phosphogluconate dehydrogenase and sulphotransferase remained unchanged, while glucose-6-phosphate dehydrogenase increased by 29%. There were no widespread changes in hepatic and renal pathology or histology, but noteworthy was a mild, focal, centrilobular hepatic response. By contrast, there were severe intestinal lesions: the effects on hepatic enzymes might have been partly a consequence of the intestinal damage. There was a reversible uraemia and significant decreases (20-40% below normal) in both serum albumin and protein, while serum levels of creatinine and aspartate-amino-transferase activity remained constant. A reversible N-acetyl-beta-D-glucoseaminidase (NAG) enzymuria occurred (300% above normal), but no significant proteinuria (less than 300 mg/l). Administration of 16, 16-dimethylprostaglandin F2 alpha(0.5 mg/kg iv) concomitantly with the indomethacin greatly ameliorated the intestinal lesions and prevented the decreases in hepatic drug-metabolizing enzymes. Concomitant 16,16-dimethylprostaglandin F2 alpha did not, however, influence the indomethacin-induced decreases in serum protein, albumin or NAG-enzymuria. It was concluded that indomethacin had a highly selective effect causing a decrease in hepatic cytochrome P-450, which was not accompanied by severe damage to hepatocyte structure.
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PMID:Comparative effects of indomethacin on hepatic enzymes and histology and on serum indices of liver and kidney function in the rat. 393 37

Genetically obese normotensive rats, LA/N-corpulent (cp), were fed ad libitum diets containing either 54% sucrose or cooked corn starch for 12 weeks. Twenty-four rats were used for the study; half were corpulent (cp/cp) and half were lean (cp/+ or +/+). Fasting levels of plasma insulin, glucose, corticosterone, glucagon and growth hormone, and activities of liver and epididymal fat pad glucose-6-phosphate dehydrogenase (G6PD), malic enzyme (ME), and liver and kidney glucose-6-phosphatase (G6Pase), fructose 1,6-diphosphatase (FDPase), and phosphoenolpyruvate carboxykinase (PEPCK) were measured. A significant phenotype effect was observed in insulin, corticosterone, growth hormone, and liver G6PD, ME, FDPase, and kidney PEPCK, G6Pase, FDPase, and epididymal fat pad G6PD and ME (corpulent greater than lean), and glucagon (lean greater than corpulent). Diet effect (sucrose greater than starch) was significant for plasma glucose, liver ME, and kidney G6Pase. Although not significant at the P less than 0.05 level, insulin, corticosterone, liver G6PD and FDPase and kidney FDPase tended to be higher in sucrose-fed rats. This study suggests that the corpulent rat is more lipogenic and gluconeogenic than the lean, and that the hormones responsible are effective in keeping both the lipogenic and gluconeogenic enzyme activity elevated.
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PMID:Hormonal and lipogenic and gluconeogenic enzymatic responses in LA/N-corpulent rats. 399 2

The endogenous synthesis of cholesterol in hepatocyte nodules, induced in male Wistar rats, by a single dose of the hepatocarcinogen diethylnitrosamine followed by a selection procedure, was investigated and was compared with that in surrounding and control tissue. In addition, the activity of enzymes related to carbohydrate metabolism (glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, glucose-6-phosphatase and pyruvate kinase), was measured. Hepatocyte nodules showed a striking increase in their capacity for synthesizing cholesterol, in comparison to surrounding and control tissues, and an enhancement in the activity of the pentose phosphate pathway, as indicated by increased activity of glucose-6-phosphate dehydrogenase and of 6-phosphogluconate dehydrogenase, and a concomitant decrease of glucose-6-phosphatase. The stimulation of cholesterol synthesis and of the pentose phosphate pathway was associated with increased incorporation of labelled thymidine into DNA. These data indicate that, among other metabolic disturbances, enhancement of cholesterol synthesis and of the pentose phosphate pathway, is accompanied by an increased proliferative capacity of hepatocyte nodules.
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PMID:Enhancement of cholesterol synthesis and pentose phosphate pathway activity in proliferating hepatocyte nodules. 402 34

Sixteen obese (fa/fa) Zucker rats, sixteen lean (Fa/-) Zucker rats and sixteen Wistar rats, all male rats aged 7-8 weeks, were given either a control (C) diet containing no ethanol or an ethanol (E) diet in which 36% of the energy was supplied by ethanol, for a period of 4 weeks. The activities of glucose-6-phosphate dehydrogenase (EC 1.1.1.49), glucose-6-phosphatase (EC 3.1.3.9) and glycerol kinase (EC 2.7.1.30) and the glycogen content in the livers of obese (fa/fa) rats were lower in animals given diet E than in those given diet C. As a result, hepatic lipogenesis and fatty degeneration of the liver were reduced in obese (fa/fa) rats given diet E.
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PMID:Paradoxical effect of ethanol on liver lipogenesis in the genetically-obese Zucker rat. 406 99

It is shown that the administration of ethanol to male Wistar rats (3 g/kg by gastric tube 3 times a week for 2 months) before or at the beginning of the N-nitrosodiethylamine (NDEA) treatment (2.5 mg/kg 6 times a week in drinking water) reduces the hepatocarcinogenicity of NDEA. This was expressed macroscopically by less important neoplastic changes and biochemically by the higher glucose-6-phosphatase and lower glucose-6-phosphate dehydrogenase activities in the liver.
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PMID:[Effect of ethanol on the hepatocarcinogenic action of N-nitrosodiethylamine in rats]. 406 16

The influence of sodium phenobarbital (PB) treatment on the sequence of N-nitrosomorpholine (NNM) induced focal preneoplastic lesions in the rat liver was investigated using a combined morphological and enzyme histochemical approach. Quantitative assessment of the different types of foci of altered hepatocytes visible in H&E sections after carcinogen application, namely the clear and acidophilic cell glycogen storage foci and mixed cell foci comprising glycogen storing cells and also more basophilic hepatocytes showing reduction in glycogen reserves, revealed a shift towards mixed cell character and greater size in PB-treated livers in comparison to those receiving NNM alone. Within the three dose levels of PB investigated (0.75, 0.075 or 0.0075 g/l drinking water) a clear dose dependence in appearance of mixed cell foci was apparent. Assessment of alterations in the activities of marker enzymes observed within preneoplastic foci was carried out by comparison of PAS preparations with sections reacted for glucose-6-phosphate dehydrogenase (G6PDH), gamma-glutamyl transpeptidase, glucose-6-phosphatase and adenosine triphosphatase. G6PDH proved the most consistent enzyme marker for small glycogen storage foci whereas larger foci of that type and mixed cell foci were associated with change in activity of all enzymes studied. The results are discussed in relation to the sequence of events occurring during hepatocarcinogenesis and the influence of PB on altered cellular populations. The applicability of enzyme markers is further considered in view of the question of heterogeneity within populations of preneoplastic foci.
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PMID:Enhancement of NNM-induced carcinogenesis in the rat liver by phenobarbital: a combined morphological and enzyme histochemical approach. 613 86

A recently developed method for the (quantitative) demonstration of glucose-6-phosphate dehydrogenase activity in individual cells with the use of a polyacrylamide carrier has been extended for other enzyme cytochemical techniques. Isolated hepatocytes have been incorporated in the matrix of a thin transparent polyacrylamide gel prior to incubation in a cytochemical medium. The techniques which have been applied are the synthetizing reaction technique for glycogen phosphorylase, the indigogenic method for nonspecific esterase, the metal salt method for glucose-6-phosphatase, the post-azo-coupling technique for acid phosphatase, and the tetrazolium salt technique for succinate and lactate dehydrogenase activities. In all cases a few major problems which occur in the cytochemistry on single cells seem to be solved. The morphology is very well preserved, the final reaction product seems to be precipitated at the expected site of enzyme activity and the coloured end-product is highly specific for the enzyme activity to be studied, as has been demonstrated well with control experiments. The conclusion is reached, therefore, that this relatively simple device can be used routinely for the optimalization of enzyme cytochemistry of single cells.
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PMID:Enzyme cytochemical staining of individual cells with the use of a polyacrylamide carrier. Studies on the synthetizing reaction technique, the indigogenic method, the metal salt method, the post-azo-coupling technique, and the tetrazolium salt technique. 619 80


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