Gnaiger 2011 Abstract-MonteVerita: Difference between revisions
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|authors=Gnaiger E | |authors=Gnaiger E | ||
|year=2011 | |year=2011 | ||
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|abstract='''Mitochondrial capacity''': [[OXPHOS]] capacity is evaluated in isolated mitochondria (mt) and permeabilized cells with physiological substrate cocktails to reconstitute tricarboxylic acid cycle function. As a consequence, convergent electron flow from Complexes CI+II of the electron transfer system ([[ETS]]) to the [[Q-junction]] exerts an additive effect on flux [1]. | |abstract='''Mitochondrial capacity''': [[OXPHOS]] capacity is evaluated in isolated mitochondria (mt) and permeabilized cells with physiological substrate cocktails to reconstitute tricarboxylic acid cycle function. As a consequence, convergent electron flow from Complexes CI+II of the electron transfer system ([[ETS]]) to the [[Q-junction]] exerts an additive effect on flux [1]. | ||
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[7] [[Pesta_2011_AJP|Pesta et al 2011 AJP]]; [[Jacobs_2011_JAP|Jacobs et al 2011 JAP]] | [7] [[Pesta_2011_AJP|Pesta et al 2011 AJP]]; [[Jacobs_2011_JAP|Jacobs et al 2011 JAP]] | ||
|mipnetlab=AT Innsbruck Gnaiger E | |mipnetlab=AT Innsbruck Gnaiger E | ||
|journal=Abstract | |||
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|tissues=Skeletal Muscle | |tissues=Skeletal Muscle | ||
|kinetics=Oxygen | |kinetics=Oxygen | ||
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Revision as of 10:04, 21 November 2011
Gnaiger E (2011) Mitochondrial respiratory capacity at maximum aerobic exercise levels: Are intracellular oxygen levels limiting? Abstract Monte Verita. |
Link: The impact of hypoxia on cells, mice and men
Gnaiger E (2011)
Event: Monte Verita
Mitochondrial capacity: OXPHOS capacity is evaluated in isolated mitochondria (mt) and permeabilized cells with physiological substrate cocktails to reconstitute tricarboxylic acid cycle function. As a consequence, convergent electron flow from Complexes CI+II of the electron transfer system (ETS) to the Q-junction exerts an additive effect on flux [1].
Oxygen kinetics of mt-respiration: The apparent Km,O2 or c50 [ยตM] (p50 [kPa]) of mt-respiration increases linearly with respiratory capacity controlled by metabolic state, from 0.2 to 1.6 ยตM determined by high-resolution respirometry. O2 gradients are significant only in large cells including cardiomyocytes. The apparent p50 increases 100-fold in permeabilized muscle fibers due to diffusion gradients [2].
mt-function at VO2max: Aerobic capacity of the human leg muscle exceeds maximum O2 uptake of isolated mitochondria [3] and v. lateralis during VO2max [4]. Therefore, oxygen supply limits aerobic performance, proportional to the apparent mt-excess capacity [5]. mt-respiration is more sensitive to average pO2 in heterogenous tissues than under homogenous conditions in vitro. Tissue heterogeneity increases the kinetic dependence of flux on average intracellular pO2. High mt-density reinforces the steepness of oxygen gradients and oxygen heterogeneity in the tissue, contributing to the O2 limitation in athletic vs sedentary individuals at VO2max [6]. This provides a functional rationale for the observation that hypoxia does not specifically trigger mt-biogenesis [7].
Contribution to K-Regio MitoCom Tyrol.
[1] Gnaiger 2009; Lemieux et al 2011 Int. J. Biochem. Cell Biol.
[2] Gnaiger 2003; Scandurra, Gnaiger 2010 Adv. Exp. Med. Biol.
[3] Rasmussen et al 2001 AJP
[4] Boushel et al 2011 Mitochondrion
[6] Richardson et al; Haseler et al JAP
[7] Pesta et al 2011 AJP; Jacobs et al 2011 JAP
โข O2k-Network Lab: AT Innsbruck Gnaiger E
Labels:
Stress:Hypoxia Organism: Human Tissue;cell: Skeletal Muscle"Skeletal Muscle" is not in the list (Heart, Skeletal muscle, Nervous system, Liver, Kidney, Lung;gill, Islet cell;pancreas;thymus, Endothelial;epithelial;mesothelial cell, Blood cells, Fat, ...) of allowed values for the "Tissue and cell" property.
HRR: Oxygraph-2k