Gnaiger 1995 J Bioenerg Biomembr

Gnaiger E, Steinlechner-Maran R, Méndez G, Eberl T, Margreiter R (1995) Control of mitochondrial and cellular respiration by oxygen. J Bioenerg Biomembr 27: 583-596.

» PMID: 8746845

Gnaiger E, Steinlechner-Maran R, Mendez G, Eberl T, Margreiter R (1995) J Bioenerg Biomembr

Abstract: Control and regulation of mitochondrial and cellular respiration by oxygen is discussed with three aims: (1) A review of intracellular oxygen levels and gradients, particularly in heart, emphasizes the dominance of extracellular oxygen gradients. Intracellular oxygen pressure, pO₂, is low, typically one to two orders of magnitude below incubation conditions used routinely for the study of respiratory control in isolated mitochondria. The pO₂ range of respiratory control by oxygen overlaps with cellular oxygen profiles, indicating the significance of pO₂ in actual metabolic regulation. (2) A methodologically detailed discussion of high-resolution respirometry is necessary for the controversial topic of respiratory control by oxygen, since the risk of methodological artefact is closely connected with far-reaching theoretical implications. Instrumental and analytical errors may mask effects of energetic state and partially explain the divergent views on the regulatory role of intracellular pO₂ . Oxygen pressure for half-maximum respiration, p₅₀, in isolated mitochondria at state 4 was 0.025 kPa (0.2 Torr; 0.3 µM O2), whereas p₅₀ in endothelial cells was 0.06–0.08 kPa (0.5 Torr). (3) A model derived from the thermodynamics of irreversible processes was developed which quantitatively accounts for near-hyperbolic flux/pO₂ relations in isolated mitochondria. The apparent p₅₀ is a function of redox potential and protonmotive force. The protonmotive force collapses after uncoupling and consequently causes a decrease in p₅₀. Whereas it is becoming accepted that flux control is shared by several enzymes, insufficient attention is paid to the notion of complementary kinetic and thermodynamic flux control mechanisms. • Keywords: Oxygen limitation, p₅₀, Critical oxygen pressure, Respirometry, Polarographic oxygen sensor, Human endothelial cells, Rat liver mitochondria, Intracellular pO₂, Oxygen gradients, Kinetics, Nonequilibrium thermodynamics

• O2k-Network Lab: AT_Innsbruck_Gnaiger E

Labels:

Stress:Hypoxia  Organism: Human, Rat  Tissue;cell: Endothelial; Epithelial; Mesothelial Cell"Endothelial; Epithelial; Mesothelial Cell" 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.  Preparation: Intact Cell; Cultured; Primary"Intact Cell; Cultured; Primary" is not in the list (Intact organism, Intact organ, Permeabilized cells, Permeabilized tissue, Homogenate, Isolated mitochondria, SMP, Chloroplasts, Enzyme, Oxidase;biochemical oxidation, ...) of allowed values for the "Preparation" property., Isolated Mitochondria"Isolated Mitochondria" is not in the list (Intact organism, Intact organ, Permeabilized cells, Permeabilized tissue, Homogenate, Isolated mitochondria, SMP, Chloroplasts, Enzyme, Oxidase;biochemical oxidation, ...) of allowed values for the "Preparation" property. 

Regulation: Respiration; OXPHOS; ETS Capacity"Respiration; OXPHOS; ETS Capacity" is not in the list (Aerobic glycolysis, ADP, ATP, ATP production, AMP, Calcium, Coupling efficiency;uncoupling, Cyt c, Flux control, Inhibitor, ...) of allowed values for the "Respiration and regulation" property. 

HRR: Oxygraph-2k 

Made history 

Follow-up reviews on mitochondrial and cellular oxygen kinetics:

• Gnaiger 1998 Biochim Biophys Acta, Gnaiger 1998 J Exp Biol
• Gnaiger 2001 Respir Physiol
• Gnaiger 2002 Biochem Soc Trans
• Gnaiger 2003 Adv Exp Med Biol
• Scandurra 2010 Adv Exp Med Biol

Follow-up reviews on high-resolution respirometry:

• Gnaiger 2001 Respir Physiol
• Huetter 2006 Exp Gerontol
• Gnaiger 2008 POS
• Pesta 2012 Methods Mol Biol