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

Changes in the specific activities of acetyl-CoA-carboxylase (ACX), malic enzyme (ME) and glucose-6-phosphate dehydrogenase (G-6-PD) were compared to changes in de novo lipogenesis measured by in vivo incorporation of [3H] of tritiated water into fatty acids of liver and of perirenal and dorsal subcutaneous adipose tissues. In the adipose tissues, the specific activities of the three enzymes rather closely followed fluctuations in the rate of fatty acid synthesis. In the liver, ACX and especially ME activities were satisfactory indicators of de novo lipogenesis; G-6-PD activity did not depend on de novo lipogenesis.
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PMID:Comparative changes in the lipogenic enzyme activities and in the in vivo fatty acid synthesis in liver and adipose tissues during the post-weaning growth of male rats. 286 36

Adipose deposits and their lipogenic enzymes were studied on 27 young Alpine male kids. They were weaned either at 28, 42 or 56 days of age and for each age at weaning, 3 animals were slaughtered unweaned (P 0), or 14 (P + 14) or 56 (P +56) days after weaning. They received milk replacer ad libitum from day 5 after birth to weaning and concentrate, hay and water from a week before weaning to slaughter. The adipose tissues were very developed in the abdomen in P 0 and P + 56 animals. Subcutaneous tissues were scarce. All adipose tissues in the P + 14 were lighter. The older the animals, the greater was the reduction in adipose tissue weight between P 0 and P + 14. But this loss was proportionally higher in younger animals. In all P + 14 animals the perirenal tissues showed higher loss. Lipoprotein lipase (LPL) activity was high in abdominal adipose tissues of P 0 and P + 56 kids, particularly in the omental tissue, but was very low in sternal adipose tissue. LPL activity had a low value 14 days after weaning but its specific activity roughly reached the unweaned LPL value 56 days after weaning. By contrast, acetyl CoA carboxylase (ACX) activity was very low in omental adipose tissue but existed even in unweaned kids. Fifty-six days after weaning, this activity was high in 28-day weaned kids. The activity of both glucose-6-phosphate dehydrogenase (G6PDH) and malic enzyme (EM) was high in unweaned kids, particularly at 42 days. Surprisingly, EM activity was higher than G6PDH activity in kids weaned for 56 days. Thus, in ad libitum concentrate-fed kids, the ATP-citrate lyase EM pathway seemed to be active and important for lipogenesis.
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PMID:[Lipogenesis in adipose tissues of kids weaned at 4, 6, and 8 weeks]. 287 33

When fasted rats were refed for 4 days with a carbohydrate and protein diet, a carbohydrate diet (without protein) or a protein diet (without carbohydrate), the effects of dietary nutrients on the fatty acid synthesis from injected tritiated water, the substrate and effector levels of lipogenic enzymes and the enzyme activities were compared in the livers. In the carbohydrate diet group, although acetyl-CoA carboxylase was much induced and citrate was much increased, the activity of acetyl-CoA carboxylase extracted with phosphatase inhibitor and activated with 0.5 mM citrate was low in comparison to the carbohydrate and protein diet group. The physiological activity of acetyl-CoA carboxylase seems to be low. In the protein diet group, the concentrations of glucose 6-phosphate, acetyl-CoA and malonyl-CoA were markedly higher than in the carbohydrate and protein group, whereas the concentrations of oxaloacetate and citrate were lower. The levels of hepatic cAMP and plasma glucagon were high. The activities of acetyl-CoA carboxylase and also fatty acid synthetase were low in the protein group. By feeding fat, the citrate level was not decreased as much as the lipogenic enzyme inductions. Comparing the substrate and effector levels with the Km and Ka values, the activities of acetyl-CoA carboxylase and fatty acid synthetase could be limited by the levels. The fatty acid synthesis from tritiated water corresponded more closely to the acetyl-CoA carboxylase activity (activated 0.5 mM citrate) than to other lipogenic enzyme activities. On the other hand, neither the activities of glucose-6-phosphate dehydrogenase and malic enzyme (even though markedly lowered by diet) nor the levels of their substrates appeared to limit fatty acid synthesis of any of the dietary groups. Thus, it is suggested that under the dietary nutrient manipulation, acetyl-CoA carboxylase activity would be the first candidate of the rate-limiting factor for fatty acid synthesis with the regulations of the enzyme quantity, the substrate and effector levels and the enzyme modification.
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PMID:Effects of dietary nutrients on substrate and effector levels of lipogenic enzymes, and lipogenesis from tritiated water in rat liver. 287 38

F344 Male rats weighting between 90 and 110 gm were given 90 ppm diethylnitrosamine in their drinking water for 5 weeks. Seven weeks after the administration of carcinogen was completed, the rats were sacrificed and sections of their livers were embedded in methacrylate. Serial sections 2 or 4 micron in thickness demonstrated the presence of gamma-glutamyl transpeptidase, acid phosphatase, adenosine triphosphatase, aldehyde dehydrogenase, alkaline phosphatase, alpha-naphthyl butyrate esterase, DT diaphorase, glucose-6-phosphate dehydrogenase, and 5'-nucleotidase activity and glycogen. The use of 4-micron sections of methacrylate-embedded tissue allows the evaluation of many more phenotypic markers in serial sections than is currently possible with frozen sections.
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PMID:Examination of enzyme-altered foci with gamma-glutamyl transpeptidase, aldehyde dehydrogenase, glucose-6-phosphate dehydrogenase, and other markers in methacrylate-embedded liver. 287 68

The rates of ATP synthesis and release by the dynein ATPase were determined in order to estimate thermodynamic parameters according to the pathway: (Formula: see text). Dynein was incubated with high concentrations of ADP and Pi to drive the net synthesis of ATP, and the rate of ATP production was monitored fluorometrically by production of NADPH through a coupled assay using hexokinase and glucose-6-phosphate dehydrogenase. The turnover number for the rate of release of ATP from 22S dynein was 0.01 s-1 per site at pH 7.0, 28 degrees C, assuming a molecular weight of 750 000 per site. The same method gave a rate of ATP synthesis by myosin subfragment 1 of 3.4 X 10(-4) s-1 at pH 7.0, 28 degrees C. The rate of ATP synthesis at the active site was estimated from the time dependence of medium phosphate-water oxygen exchange. Dynein was incubated with ADP and [18O] Pi, and the rate of loss of the labeled oxygen to water was monitored by 31P NMR. A partition coefficient of 0.31 was determined, which is equal to k-2/(k-2 + k3). Assuming k3 = 8 s-1 [Johnson, K.A. (1983) J. Biol. Chem. 258, 13825-13832], k-2 = 3.5 s-1. From the rates of ATP binding and hydrolysis measured previously (Johnson, 1983), the equilibrium constants for ATP binding and hydrolysis could be calculated: K1 = 5 X 10(7) M-1 and K2 = 14.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Rate of ATP synthesis by dynein. 293 51

Twenty adult Sprague-Dawley outbred rats (10 male and 10 female) were fed a nonpurified diet without or containing dehydroepiandrosterone acetate (DHEA 6 g/kg diet) for 11 w. DHEA-treated animals weighed less than the controls after 6 wk and until the end of treatment. However, only the differences between male groups were statistically significant. Food intake of the DHEA-fed animals was not affected, but resting heat production was elevated for both sexes. Serum triglyceride levels and activity of hepatic glucose-6-phosphate dehydrogenase of the experimental groups were lower than controls. Analyses of body composition indicated DHEA-treated animals had proportionately less body fat and therefore more body water, protein and ash than controls. In most cases, differences in body composition were due primarily to effects of DHEA on the female animals. In a second experiment, DHEA treatment did not alter urinary ketone levels nor did it enhance citrate synthase activity in interscapular brown fat, skeletal muscle, heart or liver. Findings suggest that DHEA acetate treatment affected body weight, body composition and utilization of dietary energy by both impairing fat synthesis and promoting fat-free tissue deposition and resting heat production. Possible mechanisms by which DHEA may affect metabolism are discussed.
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PMID:Effects of dehydroepiandrosterone acetate on metabolism, body weight and composition of male and female rats. 294 8

Rat lenses with experimentally induced cataract (either by naphthalene or by streptozotocin) were analyzed biochemically. Both noxae had some effects in common. Water-soluble protein and aldose reductase activity decreased, and glucose-6-phosphate dehydrogenase, phosphofructokinase and glutathione reductase activity increased. A specific effect of streptozotocin was the rise in glucose, fructose and sorbitol. A specific effect of naphthalene was increased amounts of water-insoluble protein.
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PMID:Alterations of lens metabolism with experimentally induced cataract in rats. 297 80

The connection between metabolic and sea water adaptation of the rainbow trout was investigated. The rainbow trout were kept in fresh water and diluted sea water of 8 and 20 0/00 S at 16 degrees C and fed on three different diets for 51 days. Hyperosmotic salinity (20 0/00) tends to inhibit growth in rainbow trout by reducing the food conversion efficiency. A higher protein concentration in the diet can partly compensate for this effect. The liver IDH, G6PDH and 6PGDH activities of the rainbow trout are influenced only by food quality, whereas the liver G1DH, AspT and A1T activities, like the muscle A1T, are also affected by salinity. The salinity had no significant effect on the activities of the kidney enzymes we investigated (Na/K-ATPase, G1DH, A1T, AspT) or of the muscle AspT in these experiments.
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PMID:Influence of salinity and ratio of lipid to protein in diets on certain enzyme activities in rainbow trout (Salmo gairdneri Richardson). 299 Aug 8

It was established that water deprivation during 3, 6, 9 days caused a distinct decrease in phospholipid level and disturbances of phospholipid composition in the rat lung tissue. It was accompanied by alterations in the activity of antioxidant defense system enzymes (superoxide dismutase, glutathione peroxidase, glutathione reductase, catalase, glucose-6-phosphate dehydrogenase). These data are indicative of lipid peroxidation intensification in the rat lungs during water deprivation.
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PMID:[Changes in the phospholipid-phospholipid ratios and the enzyme activity of antioxidant protection in the rat lung during dehydration]. 302 Dec 59

Some physicochemical properties of partially purified hypothalamic material from the spontaneously hypertensive rat, and of plasma from man and the rat, have been characterized using a validated cytochemical bioassay which measures the ability of biological fluids to stimulate fresh guinea-pig kidney glucose-6-phosphate dehydrogenase (G6PD) after 2 min of exposure to the test substance, as an indication of their ability to inhibit Na+/K+ adenosine triphosphatase (Na+/K+-ATPase) after 4-6 min of exposure. The G6PD-stimulating activity of both hypothalamic extract and plasma is soluble in water and insoluble in chloroform. During electrophoresis the activity from both sites appears in the same fractions and travels considerably further than lysine. After high-pressure liquid chromatography the activity of hypothalamic extract appears in a discreet fraction which does not absorb u.v. light. The activity of both the hypothalamic extract and plasma survives boiling and acid hydrolysis, but is substantially inhibited by prior incubation with digoxin antibody. From ultrafiltration studies, the substance responsible for the ability to stimulate G6PD appears to have a molecular weight of less than 500. The G6PD-stimulating activity of hypothalamic extracts was destroyed by ashing and by base hydrolysis. The ability of plasma of high activity to stimulate G6PD is considerably increased by incubating at 37 degrees C for 15 min and destroyed by incubation for 45 min. It is concluded that these and several other previously noted similarities suggest that the cytochemically assayable Na+/K+-ATPase-inhibiting/G6PD-stimulating activity in the plasma and hypothalamus may be due to the same ouabain-like substance.
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PMID:Extraction and characterization of a cytochemically assayable Na+/K+-ATPase inhibitor/glucose-6-phosphate dehydrogenase stimulator in the hypothalamus and plasma of man and the rat. 302 64


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