scholarly journals Metabolic control and regulation of the tricarboxylic acid cycle in photosynthetic and heterotrophic plant tissues

2011 ◽  
Vol 35 (1) ◽  
pp. 1-21 ◽  
Author(s):  
WAGNER L. ARAÚJO ◽  
ADRIANO NUNES-NESI ◽  
ZORAN NIKOLOSKI ◽  
LEE J. SWEETLOVE ◽  
ALISDAIR R. FERNIE
Keyword(s):  
Metabolic Control ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Plant Tissues ◽  
Acid Cycle

Studies in the respiratory and carbohydrate metabolism of plant tissues XIII. The influence of oxygen at high pressures in increasing and decreasing the respiration of potatoes at 15 °C

1963 ◽  
Vol 158 (971) ◽  
pp. 143-155 ◽  
Keyword(s):  
Carboxylic Acid ◽  
Carbohydrate Metabolism ◽  
High Pressures ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Total Carbon ◽  
Plant Tissues ◽  
Sugar Phosphate ◽  
Oxygen Inhibition ◽  
Acid Cycle

The CO 2 output of potatoes held at 15 °C in oxygen at a pressure of either 2 or 3 atm was first decreased, then increased and finally again decreased. The increase of CO 2 output was much larger than in carrots (Barker 1961); in oxygen at a pressure of 2 atm the rate of CO 2 output of potatoes was increased 4.6 fold; taking into account the accumulation of citrate, the ‘total carbon traffic’ was increased 5.6 fold in oxygen. This increase was believed to occur mainly in a pathway which was not the tricarboxylic acid cycle. As in potatoes held at 1 °C in an atmosphere of oxygen (Barker & Mapson 1955), citrate accumulated and α -ketoglutarate decreased in potatoes, held at 15 °C in oxygen at pressures of 2 or 3 atm; these changes were accepted as demonstrating the occurrence of the tri­-carboxylic acid cycle. The final decrease of CO 2 output in oxygen appeared not to be related to the occurrence of ‘blocks’ either between citrate and α -ketoglutarate or of pyruvate or α -ketoglutarate oxidases; the inhibition might be due to a shortage of sugar phosphate substrates, caused possibly by oxygen inhibition of cytochrome- c reductase. The outburst of CO 2 , which occurred in potatoes first held in oxygen and then returned to air, could not be attributed solely to oxidation of accumulated citrate.

Studies in the respiratory and carbohydrate metabolism of plant tissues - IX. Experimental studies of the influence of oxygen at high pressures on the respiration of apples and of a 'block' in the tricarboxylic acid cycle induced by 'oxygen poisoning'

1960 ◽  
Vol 152 (946) ◽  
pp. 88-108 ◽  
Keyword(s):  
Carbohydrate Metabolism ◽  
High Pressures ◽  
Tricarboxylic Acid Cycle ◽  
Experimental Studies ◽  
Tricarboxylic Acid ◽  
Plant Tissues ◽  
Acid Cycle ◽  
Marked Inhibition ◽  
Oxygen Poisoning

In contrast with peas (Turner & Quartley 1956; Pritchard 1959) apples treated with oxygen at pressures of 2½ or 5 atm showed complex changes with time in the rate of CO 2 output. These changes appeared to be due to the opposed effects of inhibitory and stimulatory processes; the latter caused a large increase in the rate of respiration in oxygen as compared with that of samples held in air. Although then the observed rate of CO 2 output after several days in oxygen was, in general, only a little slower than the rate in air, taking into account the increased rate of respiration in oxygen, there was in fact a marked inhibition of a part or parts of the respiratory process. There was also an accumulation in oxygen of pyruvate, alcohol and citrate and a decrease in the contents of α -ketoglutarate and oxaloacetate, as compared with apples in air. As in the earlier work with potatoes and peas (Barker & Mapson 1955; Turner & Quartley 1956), these changes in the acids were attributed in part to the production of an enzymic ‘block’ in the tricarboxylic acid cycle between citrate and α -ketoglutarate. The indication in previous work (Allentoff, Phillips & Johnston 1954) that the tricarboxylic acid cycle may operate in apples was thus supported. The paper includes data on the influence of a return to air at a pressure of one atmosphere following subjection to oxygen at high pressures.

The aerobic utilization of pyruvate in plant tissues

1959 ◽  
Vol 150 (939) ◽  
pp. 192-198 ◽  
Keyword(s):  
Amino Acids ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Methyl Groups ◽  
Plant Tissues ◽  
Root Tips ◽  
Acid Cycle ◽  
Amino Butyric Acid ◽  
Apple Tissue

Pyruvate with 14 C-labelling in the carbonyl and methyl groups was supplied to apple tissue and to root tips of barley. After incubation the labelling was found in a series of carboxylic acids and in alanine, glutamic acid, aspartic acid and γ -amino-butyric acid. Glutamine and asparagine were also labelled; but several other amino acids whose presence was demonstrated were without label after 4 h. Sugars and polysaccharides were also unlabelled. The CO 2 given off invariably contained 14 C, but the specific activity was much lower than that of the pyruvate supplied. It is concluded that the fed pyruvate only very partially replaced internal substrates and that it was oxidized in a tricarboxylic acid cycle. It gave rise to alanine by direct amination and to other amino acids after partial oxidation. No pyruvate was built back to sugars or other carbohydrates in either tissue.

scholarly journals Effects of sevoflurane anesthesia and abdominal surgery on the systemic metabolome: a prospective observational study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yiyong Wei ◽  
Donghang Zhang ◽  
Jin Liu ◽  
Mengchan Ou ◽  
Peng Liang ◽  
...  
Keyword(s):  
Abdominal Surgery ◽  
General Anesthesia ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Metabolic Changes ◽  
Sevoflurane Anesthesia ◽  
Glutamate Metabolism ◽  
Acid Cycle ◽  
Link Type ◽  
The Mean

Abstract Background Metabolic status can be impacted by general anesthesia and surgery. However, the exact effects of general anesthesia and surgery on systemic metabolome remain unclear, which might contribute to postoperative outcomes. Methods Five hundred patients who underwent abdominal surgery were included. General anesthesia was mainly maintained with sevoflurane. The end-tidal sevoflurane concentration (ETsevo) was adjusted to maintain BIS (Bispectral index) value between 40 and 60. The mean ETsevo from 20 min after endotracheal intubation to 2 h after the beginning of surgery was calculated for each patient. The patients were further divided into low ETsevo group (mean − SD) and high ETsevo group (mean + SD) to investigate the possible metabolic changes relevant to the amount of sevoflurane exposure. Results The mean ETsevo of the 500 patients was 1.60% ± 0.34%. Patients with low ETsevo (n = 55) and high ETsevo (n = 59) were selected for metabolomic analysis (1.06% ± 0.13% vs. 2.17% ± 0.16%, P < 0.001). Sevoflurane and abdominal surgery disturbed the tricarboxylic acid cycle as identified by increased citrate and cis-aconitate levels and impacted glycometabolism as identified by increased sucrose and D-glucose levels in these 114 patients. Glutamate metabolism was also impacted by sevoflurane and abdominal surgery in all the patients. In the patients with high ETsevo, levels of L-glutamine, pyroglutamic acid, sphinganine and L-selenocysteine after sevoflurane anesthesia and abdominal surgery were significantly higher than those of the patients with low ETsevo, suggesting that these metabolic changes might be relevant to the amount of sevoflurane exposure. Conclusions Sevoflurane anesthesia and abdominal surgery can impact principal metabolic pathways in clinical patients including tricarboxylic acid cycle, glycometabolism and glutamate metabolism. This study may provide a resource data for future studies about metabolism relevant to general anaesthesia and surgeries. Trial registration www.chictr.org.cn. identifier: ChiCTR1800014327.

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
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