CHANGES IN ENZYMES OF CARBOHYDRATE METABOLISM IN RAT UTERUS DURING EARLY PREGNANCY

ABSTRACT The enzymes phosphofructokinase (PFK), pyruvate kinase (PK), isocitric dehydrogenase (ICDH), malic dehydrogenase (MDH), glucose-6-phosphate dehydrogenase (G-6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) have been measured in rat uterus during the first 9 days of pregnancy. It was found that after implantation on day 6, the activities of PFK and PK (the key glycolytic enzymes) increased in terms of dry weight — and in terms of protein in the implantation sites, but decreased in non-implanted tissue. The pentose shunt enzymes changed similarly to those of the glycolytic enzymes. ICDH activity increased in the non-implanted tissue and decreased in the implanted tissue. Changes in malic dehydrogenase were extremely variable and did not show a consistent pattern. Administration of Actinomycin D on day 6 of pregnancy abolished the increase in PK and PFK in the implantation sites and indeed led to a major decrease in activity. This implies that the increased PK and PFK in the implantation sites, arise from a DNA dependent RNA directed synthesis of new enzyme protein. The results are discussed in relation to the energy requirement of the decidualising tissue and the need for increased pentose for RNA synthesis. It is suggested that the extra NADPH resulting from the pentose shunt is involved in increased lipid synthesis.

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EINFLUSS VON CYCLUS UND EXOGENER HORMONZUFUHR AUF STOFFWECHSELVORGÄNGE DES RATTENUTERUS

Acta Endocrinologica ◽

10.1530/acta.0.0560231 ◽

1967 ◽

Vol 56 (2) ◽

pp. 231-243 ◽

Cited By ~ 7

Author(s):

H. Schmidt ◽

I. Noack ◽

H. Walther ◽

K. D. Voigt

Keyword(s):

Isocitrate Dehydrogenase ◽

Leucine Aminopeptidase ◽

Intraperitoneal Administration ◽

Exogenous Hormone ◽

Rat Uterus ◽

Normal Cycle ◽

Phosphogluconate Dehydrogenase ◽

Dna And Rna ◽

Hormone Administration ◽

Glucose 6 Phosphate Dehydrogenase

ABSTRACT The first significant increase of weight, RNA and protein was observed in the uterus of spayed rats twelve hours after the intraperitoneal administration of a single dose of 1 μg oestradiol. There was no significant increase of DNA. At the same time the activities of glucose-6-phosphate dehydrogenase, fructose-1,6-diphosphate aldolase, isocitrate dehydrogenase and leucine aminopeptidase had increased significantly. Twentyfour hours after the injection the augmented values began to decline. Three injections of 1 μg oestradiol, given at 24 hour intervals obtained similar changes, the only difference being that these changes were more marked and that a DNA increase was also observed. The augmentation of protein, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and fructose-1,6-diphosphate aldolase content of cells induced by repeated oestradiol injections was inhibited partly by 1 mg progesterone when administered together with the last dose of oestradiol. During the normal oestrus cycle of the rat uterus an increase of uterine weight, DNA and RNA content and also of glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and 1,6-diphosphate aldolase activities was observed, whereas isocitrate dehydrogenase, malate dehydrogenase and leucine aminopeptidase did not change significantly. It would appear that the changes after exogenous hormone administration reflect those of the normal cycle as regards both their extent and timing. The importance of these findings in connection with hormone-induced pathways of uterine metabolism is discussed.

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Activity and androgenic control of glycolytic enzymes in the epididymis and epididymal spermatozoa of the rat

Biochemical Journal ◽

10.1042/bj1560527 ◽

1976 ◽

Vol 156 (3) ◽

pp. 527-537 ◽

Cited By ~ 48

Author(s):

D E Brooks

Keyword(s):

Phosphoglycerate Kinase ◽

Glycolytic Enzymes ◽

Phosphoglycerate Mutase ◽

Enzyme Release ◽

Glycerol Phosphate ◽

Phosphogluconate Dehydrogenase ◽

Duct Ligation ◽

Epididymal Spermatozoa ◽

Glucose 6 Phosphate Dehydrogenase ◽

Glycerol Phosphate Dehydrogenase

1. Procedures were developed for the extraction and assay of glycolytic enzymes from the epididymis and epididymal spermatozoa of the rat. 2. The epididymis was separated into four segments for analysis. When rendered free of spermatozoa by efferent duct ligation, regional differences in enzyme activity were apparent. Phosphofructokinase, glycerol phosphate dehydrogenase and glucose 6-phosphate dehydrogenase were more active in the proximal regions of the epididymis, whereas hexokinase, lactate dehydrogenase and phosphorylase were more active in the distal segment. These enzymes were less active in the epididymis of castrated animals and less difference was apparent between the proximal and distal segments. However, the corpus epididymidis from castrated rats had lower activities of almost all enzymes compared with other epididymal segments. 3. Spermatozoa required sonication to obtain satisfactory enzyme release. Glycolytic enzymes were more active in spermatozoa than in epididymal tissue, being more than 10 times as active in the case of hexokinase, phosphoglycerate kinase and phosphoglycerate mutase. 4. The specific activities of a number of enzymes in the epididymis were dependent on the androgen status of the animal. These included hexokinase, phosphofructokinase, aldolase, glyceraldehyde phosphate dehydrogenase, phosphoglycerate kinase, pyruvate kinase, glycerol phosphate dehydrogenase, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and phosphorylase. 5. The caput and cauda epididymidis differed in the extent to which enzyme activities changed in response to an altered androgen status. The most notable examples were hexokinase, phosphofructokinase, aldolase, phosphoglycerate kinase, 6-phosphogluconate dehydrogenase and phosphorylase.

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The effects of grass and concentrate diets on the specific activities of some enzymes of hepatic carbohydrate metabolism in sheep

British Journal Of Nutrition ◽

10.1079/bjn19760046 ◽

1976 ◽

Vol 35 (3) ◽

pp. 407-411 ◽

Cited By ~ 9

Author(s):

J. Pearce ◽

E. F. Unsworth

Keyword(s):

Carbohydrate Metabolism ◽

Malate Dehydrogenase ◽

Specific Activity ◽

Glycolytic Enzymes ◽

Phosphogluconate Dehydrogenase ◽

Specific Activities ◽

Glucose 6 Phosphate Dehydrogenase

1. Feeding sheep a concentrate diet compared with grass diets increased the hepatic specific activities of the three glycolytic enzymes studied, and that of glucose-6-phosphate dehydrogenase (EC 1.1.1.49), and reduced the specific activity of D-fructose-1,6-diphosphate 1-phosphohydrolase (EC 3.1.3.11). The specific activities of phosphogluconate dehydrogenase (EC 1.1.1.43) and malate dehydrogenase (decarboxylating) (NADP) (EC 1.1.1.40) were unaffected by diet.

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Absence of effects of dietary wheat bran on the activities of some key enzymes of carbohydrate and lipid metabolism in mouse liver and adipose tissue

British Journal Of Nutrition ◽

10.1079/bjn19860036 ◽

1986 ◽

Vol 55 (2) ◽

pp. 287-294 ◽

Cited By ~ 3

Author(s):

John C. Stanley ◽

Jacqueline A. Lambadrios ◽

Eric A. Newsholme

Keyword(s):

Body Weight ◽

Adipose Tissue ◽

Weight Gain ◽

Wheat Bran ◽

Body Weight Gain ◽

Dry Weight ◽

Phosphogluconate Dehydrogenase ◽

Carbohydrate And Lipid Metabolism ◽

Glucose 6 Phosphate Dehydrogenase ◽

High Sucrose

1. The effects of a 100 g/kg dietary substitution of wheat bran on the body-weight gain, food consumption and faecal dry weight of mice given a high-sucrose diet and on the activities of some key enzymes of carbohydrate and lipid metabolism in liver and adipose tissue were studied.2. Wheat bran had no effect on body-weight gain, food consumption or faecal dry weight.3. Wheat bran had no effect on the activities of hepatic glucose-6-phosphate dehydrogenase (EC 1.1.1.49), 6-phosphogluconate dehydrogenase (EC 1. 1.1.44), malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+) (EC 1. 1. 1.40), ATP-citrate (pro-3S)-lyase (EC 4.1.3.8), pyruvate kinase (EC 2.7.1.40) and fructose-1, 6-bisphosphatase (EC 3.1.3.11). The activity of hepatic 6-phosphofructokinase (EC 2.7.1.11) increased but only when expressed on a body-weight basis.4. Wheat bran had no effect on the activities of adipose tissue glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+), (ATP-citrate igro-3S)-lyase, hexokinase (EC 2. 7. 1. 1), 6-phosphofructokinase and pyruvate kinase.5. These results suggest that unlike guar gum and bagasse, wheat bran does not change the flux through some pathways of lipogenesis in liver and adipose tissue when mice are given high-sucrose diets.

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The effect of dietary bagasse on the activities of some key enzymes of carbohydrate and lipid metabolism in mouse liver

British Journal Of Nutrition ◽

10.1079/bjn19850126 ◽

1985 ◽

Vol 54 (2) ◽

pp. 415-420 ◽

Cited By ~ 2

Author(s):

John C. Stanley ◽

Eric A. Newsholme

Keyword(s):

Body Weight ◽

Weight Gain ◽

Food Consumption ◽

Body Weight Gain ◽

Dry Weight ◽

Weight Basis ◽

The Body ◽

Phosphogluconate Dehydrogenase ◽

Glucose 6 Phosphate Dehydrogenase ◽

High Sucrose

1. The effects of a 100 g/kg diet substitution of bagasse on the body-weight gain, food consumption and faecal dry weight of mice given a high-sucrose diet and on the activities of hepatic glucose-6-phosphate dehydrogenase (EC 1. 1. 1. 49), 6-phosphogluconate dehydrogenase (EC I. I. I. 44), malate dehydrogenase (oxaloacetatedecarboxylating) (NADP+) (EC I. I. I. 40), ATP-citrate (pro-3S) lyase (EC 4. 1. 3.8), 6-phosphofructokinase (EC 2. 7. 1. II), pyruvate kinase (EC 2.7. 1. 40) and fructose-1,6-bisphosphatase (EC 3. 1. 3. II) were studied.2. Bagasse had no effect on body-weight gain, food consumption or faecal dry weight.3. Bagasse decreased the activities of glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and phosphofructokinase expressed on a wet weight basis and on a protein basis.4. Bagasse decreased the activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydro-genase expressed on a body-weight basis.5. These results suggest that bagasse decreases the flux through some pathways of hepatic lipogenesis when mice are given high-sucrose diets.

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Poly-β-hydroxybutyrate biosynthesis and the regulation of glucose metabolism in Azotobacter beijerinckii

Biochemical Journal ◽

10.1042/bj1250055 ◽

1971 ◽

Vol 125 (1) ◽

pp. 55-66 ◽

Cited By ~ 100

Author(s):

P. J. Senior ◽

E. A. Dawes

Keyword(s):

Citrate Synthase ◽

Feedback Inhibition ◽

Carbon Sink ◽

Dry Weight ◽

Pentose Phosphate ◽

Phosphogluconate Dehydrogenase ◽

Highly Active ◽

Nutritional Conditions ◽

High Concentrations ◽

Glucose 6 Phosphate Dehydrogenase

Azotobacter beijerinckii possesses the enzymes of both the Entner–Doudoroff and the oxidative pentose phosphate cycle pathways of glucose catabolism and both pathways are subject to feedback inhibition by products of glucose oxidation. The allosteric glucose 6-phosphate dehydrogenase utilizes both NADP+ and NAD+ as electron acceptors and is inhibited by ATP, ADP, NADH and NADPH. 6-Phosphogluconate dehydrogenase (NADP-specific) is unaffected by adenosine nucleotides but is strongly inhibited by NADH and NADPH. The formation of pyruvate and glyceraldehyde 3-phosphate from 6-phosphogluconate by the action of the Entner–Doudoroff enzymes is inhibited by ATP, citrate, isocitrate and cis-aconitate. Glyceraldehyde 3-phosphate dehydrogenase is unaffected by adenosine and nicotinamide nucleotides but the enzyme is non-specific with respect to NADP and NAD. Citrate synthase is strongly inhibited by NADH and the inhibition is reversed by the addition of AMP. Isocitrate dehydrogenase, a highly active NADP-specific enzyme, is inhibited by NADPH, NADH, ATP and by high concentrations of NADP+. These findings are discussed in relation to the massive synthesis of poly-β-hydroxybutyrate that occurs under certain nutritional conditions. We propose that synthesis of this reserve material, to the extent of 70% of the dry weight of the organism, serves as an electron and carbon ‘sink’ when conditions prevail that would otherwise inhibit nitrogen fixation and growth.

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Are the “Dentatun” Complex of Viburnum Species Genetically Distinct?

HortScience ◽

10.21273/hortsci.32.3.482c ◽

1997 ◽

Vol 32 (3) ◽

pp. 482C-482

Author(s):

Candice A. Shoemaker ◽

Michael Barnett

Keyword(s):

Endangered Species ◽

Isozyme Variation ◽

Malic Dehydrogenase ◽

Cellulose Acetate Electrophoresis ◽

Tissue Samples ◽

Phosphogluconate Dehydrogenase ◽

Glucose 6 Phosphate Dehydrogenase ◽

Species Distinction ◽

Two Populations ◽

Polymorphic Enzymes

Viburnum bracteatum Rehd. is a member of the “dentatum” complex represented by at least three types: V. bracteatum, V. dentatum L., and V. rafinesquianum Schult. V. bracteatum is an endangered species in Georgia and at the federal level is a candidate as an endangered species. Two populations were located in northwestern Georgia; however, there is some concern as to whether they are in fact V. bracteatum. To determine if it is possible to distinguish between the three Viburnum species, cellulose acetate electrophoresis to detect isozyme variation was done. Polymorphic enzymes resolved were alcohol dehydrogenase, malic dehydrogenase, glucose-6-phosphate dehydrogenase, malic enzyme, 6-phosphogluconate dehydrogenase, phosphoglucomutase, and phosphoglucose isomerase. Fresh bud tissue was used, and tissue samples were electrophoresed three times for each enzyme assayed. A review of 100 phylogeny trees created with Dollop analysis was done. V. rafinesquianum, the known sample of V. bracteatum, and the 12 samples of possible V. bracteatum were all equally parsimonious. V. dentatum was consistently an outgroup. In conclusion, isozyme variation can assist in Viburnum species distinction.

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Role of pentose phosphate pathway in lipid accumulation of oleaginous fungus Mucor circinelloides

RSC Advances ◽

10.1039/c5ra20364c ◽

2015 ◽

Vol 5 (118) ◽

pp. 97658-97664 ◽

Cited By ~ 16

Author(s):

Lina Zhao ◽

Xin Tang ◽

Xiao Luan ◽

Haiqin Chen ◽

Yong Q. Chen ◽

...

Keyword(s):

Lipid Content ◽

Pentose Phosphate Pathway ◽

Lipid Accumulation ◽

Dry Weight ◽

Mucor Circinelloides ◽

Pentose Phosphate ◽

Phosphogluconate Dehydrogenase ◽

Oleaginous Fungus ◽

Glucose 6 Phosphate Dehydrogenase

Overexpressing the genes coding for glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase from the pentose phosphate pathway in the oleaginous fungusMucor circinelloidesincreased the lipid content of cell dry weight by 20–30%.

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