Studies in the respiratory and carbohydrate metabolism of plant tissues. VII. Experimental studies with potato tubers of an inhibition of the respiration and of a ‘block’ in the tricarboxylic acid cycle induced by ‘oxygen poisoning’

1955 ◽  
Vol 143 (913) ◽  
pp. 523-549 ◽  
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Experimental Studies ◽  
General Term ◽  
Tricarboxylic Acid ◽  
Pure Oxygen ◽  
Prolonged Treatment ◽  
Potato Tubers ◽  
Acid Cycle ◽  
Oxidation Reduction ◽  
Oxygen Poisoning

Prolonged treatment of potato tubers at 1° C with an atmosphere of pure oxygen eventually induces a marked inhibition of the rate of CO 2 output; there is also an accumulation of pyruvate and of 'citrate’ and a decrease in the contents of α -ketoglutarate and of malate as compared with potatoes held in air. These changes in the acids appear to be in accord with the development during sojourn in pure oxygen of a ‘block’ in the tricarboxylic acid cycle between ‘citrate’ and α -ketoglutarate. The indications in previous work (Barron, Link, Klein & Michel 1950; Barker & Mapson 1953 b ) that the tricarboxylic acid cycle may operate in potato tubers under certain metabolic conditions are thus supported. The treatment with pure oxygen also results in a progressive shift to the more oxidized state in the ascorbic acid and glutathione oxidation-reduction systems; finally, the potato tissue develops a brown discoloration presumably due to polyphenolase action. The change in the balance of the two oxidation-reduction systems towards oxidation may be caused, in part, by a reduced rate of regeneration of coenzyme II because of the ‘block’ in the tricarboxylic acid cycle. The paper also contains the results of preliminary experiments on the reversibility of the above changes. The data add to the knowledge of the varied metabolic phenomena which have been observed in many different types of living tissue, both plant and animal, and which are conveniently classified under the general term ‘oxygen poisoning’ (Stadie, Riggs & Haugaard 1944).

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.

Studies in the respiratory and carbohydrate metabolism of plant tissues - X. The influence of oxygen at high pressures as a stimulant and inhibitor of certain pathways of respiration in carrots

1961 ◽  
Vol 154 (956) ◽  
pp. 289-308 ◽  
Keyword(s):  
High Pressures ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Pentose Phosphate ◽  
High Oxygen ◽  
Total Carbon ◽  
Inhibitory Effects ◽  
Acid Cycle ◽  
Concentration Changes ◽  
Oxygen Poisoning

In contrast with the behaviour of peas (Turner & Quartley 1956; Pritchard 1959, 1961) but like that of various tissues (Johannsen 1888; Cass 1947; Barker, Quartley & Turner 1960), the rate of CO 2 output of whole carrots was stimulated initially in oxygen at a pressure of 5 atm prior to the strong inhibition characteristic of oxygen poisoning. The inhibition was associated with an accumulation of citrate together with a decrease in the contents of α -ketoglutarate, succinate, malate and oxaloacetate; later pyruvate, alcohol and acetate also increased. As in the earlier work with potatoes, peas and apples (Barker & Mapson 1955; Turner & Quartley 1956; Barker et al . 1960), these changes in the acids were attributed in part to the production of an enzymic ‘block’ first in the tricarboxylic acid cycle between citrate and α -ketoglutarate and later in the oxidation of pyruvate. The earlier observations of the activity of the tricarboxylic acid cycle in carrot slices were thus confirmed (Pritchard 1959; ap Rees & Beevers 1960). The ‘total carbon traffic’, representing the sum of the observed CO 2 output in high oxygen and the calculated amounts of CO 2 that would be derived by oxidation of the accumulations of citrate, pyruvate, alcohol and acetate, increased initially in high oxygen to a rate which was about double that of the CO 2 output in air. Considered in relation to this increased carbon traffic in respiration, there was thus initially in high oxygen a large inhibition of the CO 2 output. Oxygen at high pressures thus produced simultaneous stimula­tory and inhibitory effects on certain phases of the respiratory process in carrots. Initially in high oxygen only a small part of the CO 2 output could be accounted for by the observed concentration changes: e. g. the accumulation of citrate; a part of the ‘unknown’ CO 2 output is provisionally attributed, without direct evidence, to operation of the pentose phosphate pathway, earlier shown to be active in carrot slices (Beevers & Gibbs 1954; ap Rees & Beevers 1960).

Interactions Between Glycine Decarboxylase, the Tricarboxylic Acid Cycle and the Respiratory Chain in Pea Leaf Mitochondria

1985 ◽  
Vol 12 (2) ◽  
pp. 119 ◽  
Author(s):  
DA Day ◽  
M Neuberger ◽  
R Douce
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Glycine Decarboxylase ◽  
Succinate Oxidation ◽  
Acid Cycle ◽  
Oxidation Reduction ◽  
The Matrix ◽  
Steady State Levels ◽  
High Matrix ◽  
Respiratory Complex I

In pea leaf and potato mitochondria, external NADH oxidation was inhibited by concurrent oxidation of endogenous NADH and succinate. Succinate oxidation was also inhibited by concurrent oxidation of external NADH, but oxidation of endogenous NADH was not. NAD+-depletion studies suggested that glycine decarboxylase and other NAD-linked enzymes competed for available NAD+ within the matrix. However, at both high and low NAD+ levels, only the tricarboxylic acid cycle enzymes and malic enzyme were inhibited during concurrent oxidation with glycine. Measurements of the oxidation-reduction state of matrix NADH suggested that most of the mitochondria in the preparations contained both glycine decarboxylase and the tricarboxylic acid cycle enzymes and that steady-state levels of NADH were maximal with glycine alone as substrate. That is, there was no evidence for two populations of mitochondria being present. Nonetheless, malate stimulated state 4 and rotenone-inhibited O2 uptake in the presence of glycine. We conclude from these results that the priority glycine has as a substrate for leaf mitochondria is due to a priority that electrons from respiratory complex I have over those from complex II and the external NADH dehydrogenase, and the ability of glycine decarboxylase to compete favourably with tricarboxylic acid cycle enzymes for NAD+ in the matrix. Glycine may inhibit oxidation of other NAD-linked substrates by maintaining high matrix NADH/ NAD+ ratios. However, malate plus pyruvate appear to have access to some electron transport that is not accessible to glycine, at least under ADP-limiting conditions.

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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