Protein-bound NAD(P)H lifetime is sensitive to multiple fates of glucose carbon (Conference Presentation)

2018 ◽  
Author(s):  
Joe T. Sharick ◽  
Peter F. Favreau ◽  
Amani A. Gillette ◽  
Sophia M. Sdao ◽  
Matthew J. Merrins ◽  
...  
Keyword(s):  
Glucose Carbon

scholarly journals Synthesis of fatty acids in the perfused mouse liver

1974 ◽  
Vol 142 (3) ◽  
pp. 611-618 ◽  
Author(s):  
D. Michael W. Salmon ◽  
Neil L. Bowen ◽  
Douglas A. Hems
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
De Novo ◽  
Saturated Fatty Acids ◽  
Carbon Sources ◽  
Acid Synthesis ◽  
Hepatic Glycogen ◽  
Total Rate ◽  
Glucose Carbon

1. Fatty acid synthesis de novo was measured in the perfused liver of fed mice. 2. The total rate, measured by the incorporation into fatty acid of3H from3H2O (1–7μmol of fatty acid/h per g of fresh liver), resembled the rate found in the liver of intact mice. 3. Perfusions with l-[U-14C]lactic acid and [U-14C]glucose showed that circulating glucose at concentrations less than about 17mm was not a major carbon source for newly synthesized fatty acid, whereas lactate (10mm) markedly stimulated fatty acid synthesis, and contributed extensive carbon to lipogenesis. 4. The identification of 50% of the carbon converted into newly synthesized fatty acid lends further credibility to the use of3H2O to measure hepatic fatty acid synthesis. 5. The total rate of fatty acid synthesis, and the contribution of glucose carbon to lipogenesis, were directly proportional to the initial hepatic glycogen concentration. 6. The proportion of total newly synthesized lipid that was released into the perfusion medium was 12–16%. 7. The major products of lipogenesis were saturated fatty acids in triglyceride and phospholipid. 8. The rate of cholesterol synthesis, also measured with3H2O, expressed as acetyl residues consumed, was about one-fourth of the basal rate of fatty acid synthesis. 9. These results are discussed in terms of the carbon sources of hepatic newly synthesized fatty acids, and the effect of glucose, glycogen and lactate in stimulating lipogenesis, independently of their role as precursors.

Determination of gluconeogenesis in vivo with 14C-labeled substrates

1985 ◽  
Vol 248 (4) ◽  
pp. R391-R399 ◽  
Author(s):  
J. Katz
Keyword(s):  
Pyruvate Carboxylase ◽  
Tricarboxylic Acid Cycle ◽  
Specific Radioactivity ◽  
Tricarboxylic Acid ◽  
Pyruvate Metabolism ◽  
Acetyl Coenzyme A ◽  
Glucose Carbon ◽  
Labeling Pattern

A mitochondrial model of gluconeogenesis and the tricarboxylic acid cycle, where pyruvate is metabolized via pyruvate carboxylase and pyruvate dehydrogenase, and pyruvate kinase is examined. The effect of the rate of tricarboxylic acid flux and the rates of the three reactions of pyruvate metabolism on the labeling patterns from [14C]pyruvate and [24C]acetate are analyzed. Expressions describing the specific radioactivities and 14C distribution in glucose as a function of these rates are derived. Specific radioactivities and isotopic patterns depend markedly on the ratio of the rates of pyruvate carboxylation and decarboxylation to the rate of citrate synthesis, but the effect of phosphoenolpyruvate hydrolysis is minor. The effects of these rates on 1) specific radioactivity of phosphoenolpyruvate, 2) labeling pattern in glucose, and 3) contribution of pyruvate, acetyl-coenzyme A, and CO2 to glucose carbon are illustrated. To determine the contribution of lactate or alanine to gluconeogenesis, experiments with two compounds labeled in different carbons are required. Methods in current use to correct for the dilution of 14C in gluconeogenesis from [14C]pyruvate are shown to be erroneous. The experimental design and techniques to determine gluconeogenesis from 14C-labeled precursors are presented and illustrated with numerical examples.

Oxidation of glucose carbon entering the TCA cycle is reduced by glutamine in small intestine epithelial cells

1995 ◽  
Vol 268 (6) ◽  
pp. G879-G888 ◽  
Author(s):  
C. E. Kight ◽  
S. E. Fleming
Keyword(s):  
Small Intestine ◽  
Epithelial Cells ◽  
Glucose Oxidation ◽  
Tca Cycle ◽  
Proximal Segment ◽  
Distal Small Intestine ◽  
Glucose Carbon ◽  
The Tca Cycle ◽  
Oxidation Of Glucose ◽  
In Cells

The influence of glutamine on glucose oxidation was assessed in epithelial cells isolated from the mucosa of the proximal, mid-, and distal small intestine of young, fed, male rats. Glucose oxidation declined along the length of the small intestine, with values from the mid- and distal segments representing approximately 55% and 40%, respectively, of the value from the proximal segment. A gradient along the small intestine was noted also in the influence of glutamine on glucose oxidation: glutamine suppressed glucose oxidation approximately 60% in the proximal small intestine, 39% in the mid-intestine, and 31% in the distal small intestine. Glutamine suppressed the oxidation of glucose carbon that entered the tricarboxylic acid (TCA) cycle; this was determined using CO2 ratios derived from acetate and glucose isotopes. In cells from the proximal segment, the probability that carbon entering the cycle would complete one full turn was reduced by glutamine from 0.77 to 0.28. The entry of glucose-derived pyruvate into the TCA cycle did not appear to be influenced by the presence of glutamine, however. Glutamine had no influence on the proportion of glucose metabolism that occurred via the pentose phosphate pathway (which averaged 5% or less), but reduced flux of carbon through pyruvate carboxylase relative to flux through pyruvate dehydrogenase from 40% to 9% in cells from the proximal segment. These data suggest that, in the presence of glutamine, the fate of pyruvate carbon (derived from glucose or elsewhere) entering the TCA cycle is altered from that of oxidation to anaplerosis and subsequent efflux of TCA cycle intermediates into newly synthesized compounds.

Participation of glucose in the synthesis of glycoproteins in preimplantation mouse embryos

1990 ◽  
Vol 2 (1) ◽  
pp. 35 ◽  
Author(s):  
RG Wales ◽  
J Hunter
Keyword(s):  
Incubation Medium ◽  
Lactate Production ◽  
Glycogen Storage ◽  
High Concentration ◽  
Cell Stage ◽  
Glucose Carbon ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Morula Stage ◽  
Qualitative Changes

Electrophoretic separation of solubilized embryos incubated for 24 h in the presence of [U-14C]glucose indicated incorporation of glucose carbon into a number of protein bands. Treatment of nitrocellulose blots of electrophoretograms with glucosidases had no effect on incorporated counts, confirming that the labelled bands were not due to protein bound glycogen. Furthermore, addition of 0.1 microgram mL-1 tunicamycin to the incubation medium virtually eliminated incorporation of glucose into the protein bands but had no effect on the pattern or rate of incorporation of labelled amino acids in parallel experiments. Also the pattern of labelling of protein by glucose was reflected in the pattern of binding of Con A to the nitrocellulose blots. There were quantitative and qualitative changes in labelling as development progressed. For embryos cultured from the 2-cell stage, a small amount of label was incorporated in two major bands at relative mobility (Mr) 69 and 97 K. With culture from the 8-cell stage, three additional major bands (33, 44 and 56 K) were labelled. Embryos cultured from the morula stage showed a different profile of incorporation; there was much more active labelling, and eight major and a number of minor radioactive bands were identified. Whilst tunicamycin suppressed glucose incorporation into glycoproteins and inhibited compaction of embryos, it had little effect on other parameters of metabolism during incubation in its presence for 24 h. No significant effects of the metabolite on protein synthesis, glycogen storage, lactate production or overall macromolecular synthesis were evident. By contrast, the anabolic metabolism of embryos decompacted by long periods of exposure to tunicamycin was severely reduced although glycolysis was still unaffected. Amphomycin at very high concentration (500 micrograms mL-1) was toxic to embryos but at concentrations up to 250 micrograms mL-1 had no effect on compaction and development of blastocysts. Addition of monensin to the incubation medium [16 micrograms mL-1] did not interfere with the development of either 2-cell or 8-cell embryos to blastocysts.

scholarly journals THE ENHANCEMENT OF MACROPHAGE BACTERIOSTASIS BY PRODUCTS OF ACTIVATED LYMPHOCYTES

1973 ◽  
Vol 138 (4) ◽  
pp. 952-964 ◽  
Author(s):  
Robert E. Fowles ◽  
Ileana M. Fajardo ◽  
Jacques L. Leibowitch ◽  
John R. David
Keyword(s):  
Listeria Monocytogenes ◽  
Guinea Pig ◽  
Concanavalin A ◽  
Bactericidal Activity ◽  
Culture Supernatant ◽  
Cell Adherence ◽  
Activated Lymphocytes ◽  
Glucose Carbon ◽  
Lymphocyte Cultures ◽  
By Products

It was reported previously that the incubation of normal guinea pig macrophages with partially purified products of activated lymphocytes resulted in altered macrophage function including increased cell adherence to culture vessels, spreading, phagocytosis, and glucose carbon-1 oxidation. Studies reported here demonstrate that such macrophages also exhibit enhanced bacteriostasis. Lymphocytes were stimulated with concanavalin A, the culture supernatant was chromatographed over Sephadex G-100 and the fraction of mol wt 25,000–55,000, rich in lymphocyte mediators, was cultured with normal guinea pig macrophages for 1–3 days. Macrophages incubated with fractions from unstimulated lymphocyte cultures served as controls. The resulting macrophage monolayers were infected with Listeria monocytogenes. Macrophages incubated with mediator-rich fractions exhibited 2- to 10-fold enhanced bacteriostasis compared to controls. Further studies indicate that this enhancement was attributable to intrinsic changes in the macrophages and not simply a consequence of the number of macrophages on the monolayers. The studies support the concept that macrophage bacteriostasis can be enhanced by lymphocyte mediators. However, macrophages, which have been preincubated directly with sensitive lymphocytes and antigen exhibit even greater bacteriostasis and sometimes bactericidal capacity, suggesting that either a labile lymphocyte factor or direct lymphocyte macrophage interaction may also be involved in bactericidal activity.

Changes in propionate and glucose metabolism during synchronization of oestrus in ewes

1984 ◽  
Vol 103 (2) ◽  
pp. 317-321 ◽  
Author(s):  
S. Wilson
Keyword(s):  
Glucose Metabolism ◽  
Production Rate ◽  
Glucose Concentration ◽  
Oxidation Rate ◽  
The Other ◽  
Glucose Carbon

SUMMARYPropionate and glucose metabolism were compared in two groups of Scottish Blackface ewes, one in which ewes had been fitted with vaginal pessaries impregnated with progesterone-analogue for the synchronization of oestrus and the other when ewes were in anoestrus. In ewes given the same amount of feed, the production rate of propionate increased significantly (P < 0·05) from 33 in anoestrous ewes to 44 gC/day in ewes with pessaries. The proportion of glucose-carbon apparently synthesized from propionate also increased significantly (P < 0·05) from 0·31 in anoestrous ewes to 0·44 in ewes with pessaries. The proportion of glucose-carbon apparently recycled was also significantly (P < 0·01) increased from 0·12 to 0·22. No changes were observed in glucose concentration, production rate or oxidation rate between the two groups of ewes.

scholarly journals Changes in Denitrification Potentials and Riverbank Soil Bacterial Structures along Shibetsu River, Japan

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Yoshitaka Uchida ◽  
Hirosato Mogi ◽  
Toru Hamamoto ◽  
Miwako Nagane ◽  
Misato Toda ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Inorganic Nitrogen ◽  
Anaerobic Incubation ◽  
Community Structures ◽  
Bacterial Response ◽  
Glucose Carbon ◽  
Soil Ecosystems ◽  
Increase Rate ◽  
Before And After ◽  
C And N

Riverbank soil ecosystems are important zones in terms of transforming inorganic nitrogen (N), particularly nitrate (NO3−-N), in soils to nitrous oxide (N2O) gases. Thus, the gasification of N in the riverbank soil ecosystems may produce a greenhouse gas, N2O, when the condition is favourable for N2O-producing microbes. One of the major N2O-producing pathways is denitrification. Thus, we investigated the denitrification potentials along Shibetsu River, Hokkaido, Japan. We sampled riverbank soils from eight sites along the Shibetsu River. Their denitrification potentials with added glucose-carbon (C) and NO3−-N varied from 4.73 to 181 μg·N·kg−1·h−1. The increase of the denitrification after the addition of C and N was negatively controlled by soil pH and positively controlled by soil NH4+-N levels. Then, we investigated the changes in 16S rRNA bacterial community structures before and after an anaerobic incubation with added C and N. We investigated the changes in bacterial community structures, aiming to identify specific microbial species related to high denitrification potentials. The genus Gammaproteobacteria AeromonadaceaeTolumonaswas markedly increased, from 0.0 ± 0.0% to 16 ± 17%, before and after the anaerobic incubation with the excess substrates, when averaged across all the sites. Although we could not find a significant interaction between the denitrification potential and the increase rate of G. AeromonadaceaeTolumonas, our study suggested that along the Shibetsu River, bacterial response to added excess substrates was similar at the genus level. Further studies are needed to investigate whether this is a universal phenomenon even in other rivers.

Effects of age and fasting on gluconeogenesis from glycerol in dogs

1976 ◽  
Vol 230 (2) ◽  
pp. 362-367 ◽  
Author(s):  
SE Hall ◽  
AJ Hall ◽  
RA Layberry ◽  
M Berman ◽  
G Hetenyi
Keyword(s):  
Glucose Production ◽  
Compartment Model ◽  
Glycerol Production ◽  
Glucose Carbon ◽  
Kinetics Of

The extent of gluconeogenesis from glycerol was examined in pups and adult dogs. With use of the SAAM-26 program, a four compartment model was formulated from tracer data to calculate the kinetics of the glycerol:glucose system. In the postabsorptive state gluconeogenesis from glycerol declines with age: 13.8% of glucose carbon originated from glycerol in 0- to 4-day-old pups, 6% in adults. Approximately 50% of glycerol carbon is converted to glucose carbon independent of age. During fasting, a) the percentage of glucose carbon arising from glycerol carbon increased to 13.3% and 10.3% in adult dogs and pups 5-19 days old, respectively, in younger pups it declined to 3.4%; b) glycerol production increased in adults, but decreased in the youngest pups; c) glucose production and utilization decreased at all ages, and a smaller percentage of glycerol carbon was converted to glucose carbon, especially in the youngest pups. Thus in neonates fasting decreases gluconeogenesis from glycerol.

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