scholarly journals Compartmentation of acetyl CoA studied by analysis of tricarboxylic acid cycle acids and 3-hydroxybutyrate in bile of rats given [2,2,2-2H3]ethanol

1990 ◽  
Vol 265 (2) ◽  
pp. 569-574 ◽  
Author(s):  
C Norsten ◽  
T Cronholm
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Ketone Bodies ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Gas Chromatography Mass Spectrometry ◽  
Acetyl Coa ◽  
Acid Cycle ◽  
Tricarboxylic Acid Cycle Intermediates ◽  
Rat Bile

Acetate, 3-hydroxybutyrate, pyruvate, lactate, citrate, 2-oxoglutarate, succinate, fumarate and malate were analysed in rat bile by gas chromatography and gas chromatography/mass spectrometry of their O-melthyloxime-t-butyldimethylsilyl derivatives. The concentration of acetate increased to about 1.8 mmol/l after administration of [2,2,2-2H3]ethanol. Acetate was formed from ethanol to an extent of about 82% and retained all of the 2H at C-2, whereas 15% of the 2H had been lost in the tricarboxylic acid cycle intermediates and 24% in 3-hydroxybutyrate. Thus the exchange of 2H for 1H takes place after formation of acetyl CoA. For citrate and 3-hydroxybutyrate, 41% and 11% respectively was formed from [2,2,2-2H3]ethanol. These results indicate that different pools of acetyl CoA are used for the synthesis of ketone bodies and citrate, with the latter being derived from ethanol to a much larger extent. Smaller fractions of 2-oxoglutarate (16%) and succinate (5%) were derived from [2,2,2--2H3]ethanol, indicating significant contributions from amino acids.

13C isotopomer model for estimation of anaplerotic substrate oxidation via acetyl-CoA

1996 ◽  
Vol 271 (4) ◽  
pp. E788-E799 ◽  
Author(s):  
F. M. Jeffrey ◽  
C. J. Storey ◽  
A. D. Sherry ◽  
C. R. Malloy
Keyword(s):  
Biochemical Analysis ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acetyl Coa ◽  
Acid Cycle ◽  
Propionate Metabolism ◽  
13C Nuclear Magnetic Resonance ◽  
Isotopomer Analysis ◽  
Tricarboxylic Acid Cycle Intermediates ◽  
Anaplerotic Pathway

A previous model using 13C nuclear magnetic resonance isotopomer analysis provided for direct measurement of the oxidation of 13C-enriched substrates in the tricarboxylic acid cycle and/or their entry via anaplerotic pathways. This model did not allow for recycling of labeled metabolites from tricarboxylic acid cycle intermediates into the acetyl-CoA pool. An extension of this model is now presented that incorporates carbon flow from oxaloacetate or malate to acetyl-CoA. This model was examined using propionate metabolism in the heart, in which previous observations indicated that all of the propionate consumed was oxidized to CO2 and water. Application of the new isotopomer model shows that 2 mM [3-13C]propionate entered the tricarboxylic acid cycle as succinyl-CoA (an anaplerotic pathway) at a rate equal to 52% of tricarboxylic acid cycle turnover and that all of this carbon entered the acetyl-CoA pool and was oxidized. This was verified using standard biochemical analysis; from the rate (mumol.min-1.g dry wt-1) of propionate uptake (4.0 +/- 0.7), the estimated oxygen consumption (24.8 +/- 5) matched that experimentally determined (24.4 +/- 3).

Inhibition of CO2 fixation in group D streptococci

1969 ◽  
Vol 15 (1) ◽  
pp. 57-60 ◽  
Author(s):  
Victor F. Lachica ◽  
Paul A. Hartman
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Pyruvate Carboxylase ◽  
Co2 Fixation ◽  
Tricarboxylic Acid Cycle ◽  
Inhibitory Effect ◽  
Tricarboxylic Acid ◽  
Acetyl Coa ◽  
Acid Cycle ◽  
Tricarboxylic Acid Cycle Intermediates ◽  
Group D

The stimulatory effect of acetyl-CoA and the inhibitory effect by L-aspartate and some intermediates of the tricarboxylic acid cycle in the assimilation of CO2 by crude extracts of group D streptococci suggest that the pyruvate carboxylase of Streptococcus faecium and the phosphoenolpyruvate carboxylase of S. bovis are allosteric enzymes. This implies that these enzymes are sites for the control of the amount of aspartate and of the tricarboxylic acid cycle intermediates synthesized.

scholarly journals Triheptanoin partially restores levels of tricarboxylic acid cycle intermediates in the mouse pilocarpine model of epilepsy

2013 ◽  
Vol 129 (1) ◽  
pp. 107-119 ◽  
Author(s):  
Mussie G. Hadera ◽  
Olav B. Smeland ◽  
Tanya S. McDonald ◽  
Kah Ni Tan ◽  
Ursula Sonnewald ◽  
...  
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Pilocarpine Model ◽  
Tricarboxylic Acid Cycle Intermediates

scholarly journals Metabolic phases during the development of granulation tissue

1967 ◽  
Vol 105 (1) ◽  
pp. 333-341 ◽  
Author(s):  
Kirsti Lampiaho ◽  
E. Kulonen
Keyword(s):  
Granulation Tissue ◽  
Collagen Synthesis ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Pentose Phosphate ◽  
Acid Cycle ◽  
Short Period ◽  
Tricarboxylic Acid Cycle Intermediates ◽  
Observation Period

1. The metabolism of incubated slices of sponge-induced granulation tissue, harvested 4–90 days after the implantation, was studied with special reference to the capacity of collagen synthesis and to the energy metabolism. Data are also given on the nucleic acid contents during the observation period. Three metabolic phases were evident. 2. The viability of the slices for the synthesis of collagen was studied in various conditions. Freezing and homogenization destroyed the capacity of the tissue to incorporate proline into collagen. 3. Consumption of oxygen reached the maximum at 30–40 days. There was evidence that the pentose phosphate cycle was important, especially during the phases of the proliferation and the involution. The formation of lactic acid was maximal at about 20 days. 4. The capacity to incorporate proline into collagen hydroxyproline in vitro was limited to a relatively short period at 10–30 days. 5. The synthesis of collagen was dependent on the supply of oxygen and glucose, which latter could be replaced in the incubation medium by other monosaccharides but not by the metabolites of glucose or tricarboxylic acid-cycle intermediates.

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