Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.1.1.49 (glucose-6-phosphate dehydrogenase)
 7,794 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A cytochemical study on the localization of the enzymes glucose-6-phosphate dehydrogenase, sorbitol dehydrogenase, and alkaline phosphatase was carried out in human ampullary glands. Although the former two enzymes showed a marked reactivity, alkaline phosphatase was absent from epithelial cells. On the basis of these results it is concluded that, as in the human seminal vesicle, in the ampullary gland fructose is probably secreted via the oxidative mechanism proposed by Hers (Le Metabolisme du Fructose. Bruxelles, Arscia, 1957).
 ...
PMID:Histochemical demonstration of glucose-6-phosphate dehydrogenase, D-sorbitol dehydrogenase, and alkaline phosphatase in human ampulla ductus deferentis. 2 93

In Rhodopseudomonas capsulata the enzymes of the Entner-Doudoroff pathway and the Embden-Meyerhof pathway have been examined. Fructose-grown cells contained inducible activities of phosphoenolpyruvate-fructosephospho-transferase and 1-phosphofructokinase and only low levels of fructokinase and 6-phosphofructokinase. Although fructose-grown cells contained, in addition, all the enzymes of the Entner-Doudoroff pathway together with fructose-1,6-diphosphatase and phosphoglucose isomerase, the Entner-Doudoroff pathway was not operative in fructose catabolism and served only the degradation of glucose. The functional separation of glucose and fructose catabolism via the Entner-Doudoroff and a modified Embden-Meyerhof pathway, respectively, was confirmed by different approaches: 1. Radiorespirometric experiments with glucose and fructose labelled in positions 1, 2, 3, 3+4 and 6 have been carried out. The pattern of 14CO2-evolution from position-labelled glucose was characteristic for the Entner-Doudoroff pathway, that from position-labelled fructose for the Embden-Meyerhof pathway. 2. In the presence of arsenite up to 50% of glucose- and fructose-carbon was excreted as pyruvate. Using 1-14C-glucose, 86% of the pyruvate was labelled in the carboxyl group, whereas using 1-14C-fructose only 19% of the pyruvate was labelled in the carboxyl group. 3. A glucose-6-phosphate dehydrogenase-deficient mutant was isolated which lacked a functional Entner-Doudoroff pathway but which was unaltered in its ability to grow on fructose.
 ...
PMID:Different degradation pathways for glucose and fructose in Rhodopseudomonas capsulata. 13 34

Acitivites of the hepatic enzymes were determined in spontaneous diabetes rats. The activities of the enzymes were compared with those in normal rats and in streptozotocin diabetic rats. In the spontaneous diabetes rats, glycogen phosphorylase and glycogen synthase were 14.6 +/- 0.6 and 1.73 +/- 0.15 U respectively. The activities of both the enzymes were significantly increased. In the spontaneous diabetes rats glucokinase was 3.82 +/- 0.5 U showing a significant increase. On the contrary, the activity of the enzyme was decreased in the streptozotocin diabetic rats. Glucose-6-phosphatase was increased both in the spontaneous diabetes rats and in the streptozotocin diabetic rats. Fructose-1,6-diphosphatase was increased in the spontaneous diabetes rats. Glucose-6-phosphate dehydrogenase was increased in the spontaneous diabetes rats and decreased in the streptozotocin diabetic rats. In the spontaneous diabetes rats phosphofructokinase showed a reduction of the activity and glucose-6-phosphate dehydrogenase was elevated. These findings are consistent with the results of activities of the hepatic enzymes in adult-onset diabetic patients. These patterns of the hepatic enzymes in the spontaneous diabetes rats were different from those in the streptozotocin diabetic rats. From these patterns of activities of the hepatic enzymes, the spontaneous diabetes rats produced by repetition of selective breeding according to Goto et al. (1975,1976) are an excellent model of human adult-onset diabetes.
 ...
PMID:Activities of hepatic enzymes in spontaneous diabetes rats produced by selective breeding of normal Wistar rats. 15 47

The effect of addition of different carbohydrates (starch, glucose, fructose) to the feed was investigated using the experimental animal. Additionally, the admixture of cholesterol and of cholesterol plus cholic acid was tested. Fructose (70% of the feed) causes a slight increase in serum triglyceride concentration and a very slight increase in triglyceride concentration in the liver. Fructose and to a lesser degree glucose cause an increase in pyruvate kinase activity in the liver. The activity of glucose-6-phosphate dehydrogenase is increased slightly following high-dosed glucose, whereas the increase is very pronounced following fuctose-rich feed. The admixture of cholesterol (with cholic acid) causes a decrease in glucose-6-phosphate dehydrogenase activity up to 70%. The activity of glutamate dehydrogenase is decreased also following cholesterol admixture. A fructose-rich diet causes a slight degree of hyperlipemia with a metabolic situation similar to a latent diabetic state. This effect is greatly intensified by the addition of cholesterol and cholic acid to the diet of the rats. Especially striking was the increase in serum-free-fatty-acid concentrations in all groups of animals. This is speculated to be a sign of insulin deficiency. The so-called "carbohydrate-induced hypertriglyceridemia" is obviously intensified within a short period by the admixture of cholesterol plus cholic acid to the experimental diet.
 ...
PMID:[Effect of various dietary carbohydrates on supplementary cholesterol]. 89 66

The effects of nutrients and hormones on the mRNA levels of acetyl-CoA carboxylase, fatty acid synthase, malic enzyme, and glucose 6-phosphate dehydrogenase were examined in primary cultures of rat hepatocytes during the process of induction. The addition of both glucose and insulin to the culture medium markedly enhanced the lipogenic enzyme mRNA induction due to either of them, in 16 h. Fructose or glycerol proved to be an effective substitute for glucose, suggesting that glycolytic metabolites were involved in the mRNA induction. It is remarkable that mRNA induction of acetyl-CoA carboxylase was the most sensitive to glucose and also to insulin among the lipogenic enzymes. Polyunsaturated fatty acids markedly reduced the mRNA induction of lipogenic enzymes. Dexamethasone enhanced all the lipogenic enzyme mRNA induction by insulin. On the other hand, triiodothyronine addition greatly increased the mRNA concentrations of lipogenic enzymes, but dexamethasone decreased rather than increased the mRNA induction by triiodothyronine. The effects of insulin on the induction of the lipogenic enzyme mRNAs were similar, but those of triiodothyronine were not. Triiodothyronine markedly enhanced malic enzyme mRNA induction by insulin with dexamethasone, and tended to enhance the induction of the acetyl-CoA carboxylase and fatty acid synthase mRNAs, but not that of glucose 6-phosphate dehydrogenase mRNA. It appeared that insulin and triiodothyronine synergistically enhanced lipogenic enzyme mRNA induction by glucose, but the mechanisms were different.
 ...
PMID:Nutritional and hormonal regulation of mRNA levels of lipogenic enzymes in primary cultures of rat hepatocytes. 135 82

Nitrofurantoin is a widely utilized urinary antimicrobial drug which has been associated with pulmonary fibrosis, neuropathy, and hepatitis as well as hemolytic anemia in glucose-6-phosphate dehydrogenase-deficient individuals. Incubation of freshly isolated rat hepatocytes with nitrofurantoin caused oxygen activation as a result of futile redox cycling. Glutathione disulfide (GSSG) was formed and rapidly exported from the cell resulting in complete glutathione (GSH) depletion followed by cell death. However, fructose prevented the export of GSSG from the cell and GSH levels recovered rapidly without cytotoxicity occurring. Fructose did not affect nitrofurantoin metabolism but rapidly depleted cellular ATP levels by approximately 80% which remained depressed during the incubation period. Fructose, however, did not protect hepatocytes from nitrofurantoin-induced cytotoxicity if GSH was depleted beforehand. Protection by fructose only occurred at concentrations which caused ATP depletion. These results suggest that fructose prevents nitrofurantoin-induced toxicity by depleting ATP and thereby preventing the ATP-dependent GSSG efflux. GSSG is retained enabling NADPH and glutathione-reductase to reduce the GSSG back to GSH, thereby protecting the cell from nitrofurantoin-induced oxidative stress.
 ...
PMID:Prevention of nitrofurantoin-induced cytotoxicity in isolated hepatocytes by fructose. 189 74

1. Adult, female Xenopus laevis were subjected to 12 months of starvation. 2. Starvation resulted in a continuous reduction in the activity of both hepatic and renal glucose-6-phosphate dehydrogenase. 3. Fructose-1,6-diphosphatase was significantly reduced at months 10 and 12 in the liver, and at months 4, 10, and 12 in the kidney. 4. Pyruvate kinase activity of muscle and liver decreased during the experimental period whereas the renal enzyme remained essentially unchanged. 5. Both hepatic and renal glutamate-pyruvate transaminase (GPT) and hepatic glutamate-oxaloacetate transaminase (GOT) showed a reduction of activity after 2 and 4 months of starvation followed by an increase in GPT but not in GOT.
 ...
PMID:Long-term starvation in Xenopus laevis Daudin--III. Effects on enzymes in several tissues. 255 3

Some aspects of carbohydrate metabolism were investigated in three non-malignant, glycogen storing, cell lines derived from a primary culture of rat hepatocytes, and in the Morris hepatoma 3924 cells. The three cell lines show biochemical alterations which are, to a large extent, similar to those found in the hepatoma cells: increased activity of glycolytic enzymes and decreased activity of gluconeogenetic enzymes. An increase of glucose-6-phosphate dehydrogenase activity is also found. The three cell lines, as the Morris hepatoma cells, actively convert glucose into lactate under the in vitro conditions of culture. Fructose is not taken up as quickly as glucose and galactose is not metabolized. As compared with normal hepatocytes, the three cell lines have altered metabolism and growth behaviour. They largely resemble the preneoplastic cells appearing in rat liver at the early stages of experimental carcinogenesis.
 ...
PMID:Study of carbohydrate metabolism in glycogen storing cell lines derived from cultured rat hepatocytes. 298 18

The present study was undertaken to measure the activities of several hepatic enzymes of regulatory importance in the pathways of lipogenesis and gluconeogenesis in rats fed diets marginally deficient in copper (1.2 micrograms Cu/g of diet) and containing either fructose, glucose, or starch as the carbohydrate sources. Although all copper-deficient rats exhibited the characteristic signs of copper deficiency, they were more pronounced in rats fed the diet containing fructose. Except for the activity of phosphoenolpyruvate carboxykinase which was unaffected either by copper deficiency or by the type of dietary carbohydrate, the hepatic activities of glucose-6-phosphate dehydrogenase, malic enzyme, L-alpha-glycerophosphate dehydrogenase and fructose 1,6-diphosphatase were unaffected by copper deficiency but were affected by the type of carbohydrate in the diet. Fructose produced the greatest increase in enzymatic activities, whereas starch produced the least activity and glucose induced an intermediate effect. These results indicate that the deleterious effects of a fructose diet deficient in copper on biochemical and physiological indices could not be due to an immediate metabolite of fructose. However, the involvement of a subsequent metabolite of fructose in the mechanism of copper utilization and/or requirement cannot be excluded.
 ...
PMID:Effects of different dietary carbohydrates on hepatic enzymes of copper-deficient rats. 397 25

1. Changes in the activities of ATP citrate lyase, ;malic' enzyme, glucose 6-phosphate dehydrogenase, pyruvate kinase and fructose 1,6-diphosphatase, and in the ability to incorporate [1-(14)C]acetate into lipid have been measured in the livers of developing rats between late foetal life and maturity. 2. In male rats the activities of those systems directly or indirectly concerned in lipogenesis (acetate incorporation into lipid, ATP citrate lyase and glucose 6-phosphate dehydrogenase) fall after birth and are maintained at a low value until weaning. After weaning these activities rise to a maximum between 30 and 40 days and then decline, reaching adult values at about 60 days. ;Malic' enzyme activity follows a similar course, except that none could be detected in the foetal liver. Pyruvate kinase activity is lower in foetal than in adult livers and rises to slightly higher than the adult value in the post-weaning period. Fructose 1,6-diphosphatase activity rises from a very low foetal value to reach a maximum at about 10 days but falls rapidly after weaning to reach adult values at about 30 days. 3. Weaning rats on to a high-fat diet caused the low activities of acetate incorporation, ATP citrate lyase, glucose 6-phosphate dehydrogenase and pyruvate kinase, characteristic of the suckling period, to persist. ;Malic' enzyme and fructose 1,6-diphosphatase activities were not altered appreciably. 4. No differences could be detected in hepatic enzyme activities between males and females up to 35 days, but after this time female rats gave higher values for acetate incorporation, glucose 6-phosphate dehydrogenase activity and ;malic' enzyme activity. 5. The results are discussed in relation to changes in alimentation and hormonal influences.
 ...
PMID:Changes in hepatic lipigenesis during development of the rat. 429 24


1 2 Next >>