scholarly journals Effects of different carbohydrates and protein recovery mixtures on exogenous and endogenous substrate oxidation during subsequent exercise

2009 ◽  
Vol 6 (S1) ◽  
Author(s):  
Eva Warrick ◽  
Roderick King ◽  
John O'Hara
Keyword(s):  
Substrate Oxidation ◽  
Protein Recovery ◽  
Endogenous Substrate

scholarly journals Changes in breath 13CO2/12CO2 consequent to exercise and hypoxia

1989 ◽  
Vol 66 (6) ◽  
pp. 2919-2919
Author(s):  
T. J. Barstow ◽  
D. M. Cooper ◽  
S. Epstein ◽  
K. Wasserman
Keyword(s):  
Substrate Oxidation ◽  
Strenuous Activity ◽  
Test Page ◽  
On Line ◽  
Endogenous Substrate

Page 936: T. J. Barstow, D. M. Cooper, S. Epstein, and K. Wasserman. “Changes in breath 13CO2/12CO2 consequent to exercise and hypoxia.” Page 936, right column, sentence beginning on line 8 should read: We therefore wondered if changes in EN could be used to detect changes in endogenous substrate oxidation during exercise. Page 940, right column, sentence beginning on line 15 should read: We controlled for potential acute modulators of oxidative fuel mix (e.g., meal and activity) by the overnight fast and avoidance of strenuous activity 24 h before each test. Page 941, left column, sentence beginning on line 27 should read: In summary, Vo2 adjusts slightly more rapidly than Vco2 in the transition from rest to exercise, whereas 13CO2 adjusts much more slowly. Page 938, Table 3 footnote should read: Values are group means for individual responses averaged from 5 to 20 min of exercise. n = 7 except for WR-3 where n = 6. Hypoxia represented FiO02, = 0.15, room air FiOO2, = 0.207. *Significantly di fferent from both WR-1 conditions and WR-2 in room air (P < 0.05). Note that work above LT (WR-2 in hypoxia and WR-3) resulted in a significant increase in R.

scholarly journals Changes in breath 13CO2/12CO2 consequent to exercise and hypoxia

1989 ◽  
Vol 66 (6) ◽  
pp. 2919-2919
Author(s):  
T. J. Barstow ◽  
D. M. Cooper ◽  
S. Epstein ◽  
K. Wasserman
Keyword(s):  
Substrate Oxidation ◽  
Strenuous Activity ◽  
Test Page ◽  
On Line ◽  
Endogenous Substrate

Page 936: T. J. Barstow, D. M. Cooper, S. Epstein, and K. Wasserman. “Changes in breath 13CO2/12CO2, consequent to exercise and hypoxia.” Page 936, right column, sentence beginning on line 8 should read: We therefore wondered if changes in EN could be used to detect changes in endogenous substrate oxidation during exercise. Page 940, right column, sentence beginning on line 15 should read: We controlled for potential acute modulators of oxidative fuel mix (e.g., meal and activity) by the overnight fast and avoidance of strenuous activity 24 h before each test. Page 941, left column, sentence beginning on line 27 should read: In summary, Vo2, adjusts slightly more rapidly than Vo2 in the transition from rest to exercise, whereas 13CO2 adjusts much more slowly. Page 938, Table 3 footnote should read: Values are group means for individual responses averaged from 5 to 20 min of exercise. n = 7 except for WR-3 where n = 6. Hypoxia represented FiO02 = 0.15, room air Fioo2 = 0.207. * Significantly different from both WR-1 conditions and WR-2 in room air (P < 0.05). Note that work above LT (WR-2 in hypoxia and WR-3) resulted in a significant increase in R.

Endogenous substrate oxidation during exercise and variations in breath 13CO2/12CO2

1993 ◽  
Vol 74 (1) ◽  
pp. 133-138 ◽  
Author(s):  
J. F. Gautier ◽  
F. Pirnay ◽  
B. Jandrain ◽  
M. Lacroix ◽  
F. Mosora ◽  
...  
Keyword(s):  
Exercise Bout ◽  
Isotope Ratio Mass Spectrometry ◽  
Substrate Oxidation ◽  
Significant Rise ◽  
Total Carbohydrate ◽  
Exogenous Substrate ◽  
Major Shift ◽  
Endogenous Substrate ◽  
Endogenous Substrates ◽  
Expired Air

This study attempted to induce a major shift in the utilization of endogenous substrates during exercise in men by the use of a potent inhibitor of adipose tissue lipolysis, Acipimox, and to see to what extent this affects the 13C/12C ratio in expired air CO2. Six healthy volunteers exercised for 3 h on a treadmill at approximately 45% of their maximum O2 uptake, 75 min after having ingested either a placebo or 250 mg Acipimox. The rise in plasma free fatty acids and glycerol was almost totally prevented by Acipimox, and no significant rise in the utilization of lipids, evaluated by indirect calorimetry, was observed. Total carbohydrate oxidation averaged 128 +/- 17 (placebo) and 182 +/- 21 g/3 h (Acipimox). Conversely, total lipid oxidation was 84 +/- 5 (placebo) and 57 +/- 6 g/3 h (Acipimox; P < 0.01). Under placebo, changes in expired air CO2 delta 13C were minimal, with only a 0.49/1000 significant rise at 30 min. In contrast, under Acipimox, the rise in expired air CO2 delta 13C averaged 1/1000 and was significant throughout the 3-h exercise bout; in these conditions calculation of a "pseudooxidation" of an exogenous sugar naturally or artificially enriched in 13C, but not ingested, would have given an erroneous value of 19.8 +/- 2.6 g/3 h. Thus under conditions of extreme changes in endogenous substrate utilization, an appropriate control experiment is mandatory when studying exogenous substrate oxidation by 13C-labeled substrates and isotope-ratio mass spectrometry measurements on expired air CO2.

Redox regulation of endogenous substrate oxidation by cardiac mitochondria

2006 ◽  
Vol 291 (3) ◽  
pp. H1436-H1445 ◽  
Author(s):  
Paavo Korge ◽  
James N. Weiss
Keyword(s):  
Fatty Acids ◽  
Redox Regulation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Substrate Oxidation ◽  
Cardiac Mitochondria ◽  
The Matrix ◽  
Endogenous Substrate ◽  
Exogenous Substrates

Reactive oxygen species (ROS) play important roles in regulating mitochondrial function, as well as in ischemia-reperfusion injury and cardioprotection. Here we show that, in the absence of exogenous substrates, cardiac mitochondria have a surprisingly large capacity to phosphorylate ADP by oxidizing endogenous substrates, provided that H2O2 is removed from the extramitochondrial environment and a reduced environment is maintained in the matrix. In isolated mitochondria without exogenous substrates, addition of catalase and the membrane-permeant reducing agent N-acetylcysteine (Nac) or the ROS scavenger mercaptopropionyl glycine significantly increased the ability to phosphorylate added ADP, as demonstrated by 1) full recovery of membrane potential (Δψ) and matrix volume from ADP-induced dissipation and shrinkage, 2) ADP-dependent increase in O2 consumption, and 3) enhanced rate of ATP synthesis. Removal of extramitochondrial H2O2 by catalase was required to stimulate endogenous substrate oxidation, as shown by the increase in O2 consumption and Δψ. This effect was greatly enhanced by addition of Nac or mercaptopropionyl glycine to suppress oxidation-induced ROS increases in the matrix. Theoretical considerations, as well as reversible inhibition of O2 consumption with 3-mercaptopropionic acid and pyruvate in state 3, indicate that these substrates are fatty acids. Under in vivo conditions in which powerful antioxidant conditions are maintained, this mechanism may be important in stimulation of β-oxidation and ATP production at low levels of extramitochondrial fatty acids. Incapacitation of this mechanism may potentially contribute to mitochondrial dysfunction during oxidative stress.

Arrangement of Mitochondria in Spermatozoa of the Mexican Axolotl, Ambystoma Mexicanum

1973 ◽  
Vol 31 ◽  
pp. 626-627
Author(s):  
Ezzatollah Keyhani ◽  
Larry F. Lemanski ◽  
Sharon L. Lemanski
Keyword(s):  
Plasma Membrane ◽  
Sperm Motility ◽  
Substrate Oxidation ◽  
Ambystoma Mexicanum ◽  
Axial Filament ◽  
Mexican Axolotl ◽  
Middle Piece

Energy for sperm motility is provided by both glycolytic and respiratory pathways. Mitochondria are involved in the latter pathway and conserve energy of substrate oxidation by coupling to phosphorylation. During spermatogenesis, the mitochondria undergo extensive transformation which in many species leads to the formation of a nebemkem. The nebemkem subsequently forms into a helix around the axial filament complex in the middle piece of spermatozoa.Immature spermatozoa of axolotls contain numerous small spherical mitochondria which are randomly distributed throughout the cytoplasm (Fig. 1). As maturation progresses, the mitochondria appear to migrate to the middle piece region where they become tightly packed to form a crystalline-like sheath. The cytoplasm in this region is no longer abundant (Fig. 2) and the plasma membrane is now closely apposed to the outside of the mitochondrial layer.

229-LB: Plasma Lactate and Muscle Aerobic Substrate Oxidation: Does Elevated Lactate Precede Obesity?

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 229-LB
Author(s):  
NICHOLAS T. BROSKEY ◽  
TERRY E. JONES ◽  
ZHEN YANG ◽  
NKAUJYI KHANG ◽  
DONGHAI ZHENG ◽  
...  
Keyword(s):  
Substrate Oxidation ◽  
Plasma Lactate ◽  
Elevated Lactate

Insulin-receptor autophosphorylation and endogenous substrate phosphorylation in human adipocytes from control, obese, and NIDDM subjects

Diabetes ◽  
1990 ◽  
Vol 39 (2) ◽  
pp. 250-259 ◽  
Author(s):  
R. S. Thies ◽  
J. M. Molina ◽  
T. P. Ciaraldi ◽  
G. R. Freidenberg ◽  
J. M. Olefsky
Keyword(s):  
Insulin Receptor ◽  
Human Adipocytes ◽  
Endogenous Substrate ◽  
Substrate Phosphorylation

Oxidase Catalysis via an Aerobically Generated Dess-Martin Periodinane Analogue

2018 ◽  
Author(s):  
Asim Maity ◽  
Sung-Min Hyun ◽  
Alan Wortman ◽  
David Powers
Keyword(s):  
Chemical Synthesis ◽  
Aerobic Oxidation ◽  
Substrate Oxidation ◽  
Oxidation Catalysis ◽  
Hypervalent Iodine ◽  
Oxidation Reactions ◽  
Broad Array ◽  
Oxidation Chemistry ◽  
Reactive Oxidants

<p>Hypervalent iodine(V) reagents, such as Dess-Martin periodinane (DMP) and 2-iodoxybenzoic acid (IBX), are broadly useful oxidants in chemical synthesis. Development of strategies to access these reagents from O2 would immediately enable use of O2 as a terminal oxidant in a broad array of substrate oxidation reactions. Recently we disclosed the aerobic synthesis of I(III) reagents by intercepting reactive oxidants generated during aldehyde autoxidation. Here, we couple aerobic oxidation of iodobenzenes with disproportionation of the initially generated I(III) compounds to generate I(V) reagents. The aerobically generated I(V) reagents exhibit substrate oxidation chemistry analogous to that of DMP. Further, the developed aerobic generation of I(V) has enabled the first application of I(V) intermediates in aerobic oxidation catalysis.</p>

Photocatalytic Effect of Fe(III) on Oxidation of Two-Carbon Substrates Related to Natural Waters

1994 ◽  
Vol 59 (5) ◽  
pp. 1066-1076 ◽  
Author(s):  
Šárka Klementová ◽  
Dana M. Wagnerová
Keyword(s):  
Mathematical Model ◽  
Natural Waters ◽  
Substrate Oxidation ◽  
Quantum Yields ◽  
Ferric Ions ◽  
Photochemical Reduction ◽  
Photocatalytic Effect ◽  
Carbon Substrates ◽  
Glyoxalic Acid ◽  
The Common

The influence of ferric ions on photoinitiated reaction of dioxygen with two carbon organic acids, aldehydes and alcohols related to natural waters was demonstrated. Photocatalytic effect of ferric ions, i.e. photochemical reduction of Fe(III) as the catalyst generating step, has been found to be the common principal of these reactions. The overall quantum yields of the reactions are in the range from 0.3 to 1.2. A mathematical model designed for the mechanism of cyclic generation of catalyst in the singlet substrate oxidation by O2 was applied to the system glyoxalic acid + Fe(III); a fair agreement between the simulated and experimental kinetic curves was obtained. The experimental rate constant is 4.4 .10-4 s -1.

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