Difference between revisions of "Scandurra 2010 Adv Exp Med Biol"
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|journal=Adv. Exp. Med. Biol. | |journal=Adv. Exp. Med. Biol. | ||
|mipnetlab=AT_Innsbruck_GnaigerE | |mipnetlab=AT_Innsbruck_GnaigerE | ||
|abstract=When oxygen supply to tissues is limiting, mitochondrial respiration and ATP production are compromised. To assess the bioenergetic consequences under normoxia and hypoxia, quantitative evaluation of mitochondrial oxygen kinetics is required. Using high-resolution respirometry, the "apparent K<sub>m</sub>" for oxygen or p<sub>50</sub> of respiration in 32D cells was determined at 0.05 +/- 0.01 kPa (0.4 mmHg, 0.5 | |abstract=When oxygen supply to tissues is limiting, mitochondrial respiration and ATP production are compromised. To assess the bioenergetic consequences under normoxia and hypoxia, quantitative evaluation of mitochondrial oxygen kinetics is required. Using high-resolution respirometry, the "apparent K<sub>m</sub>" for oxygen or p<sub>50</sub> of respiration in 32D cells was determined at 0.05 +/- 0.01 kPa (0.4 mmHg, 0.5 µM, 0.25% air saturation). Close agreement with p<sub>50</sub> of isolated mitochondria indicates that intracellular gradients are small in small cells at routine activity. At intracellular p<sub>O2</sub> <2 kPa (15 mmHg, 10% air saturation) in various tissues under normoxia, respiration is limited by >2% with a p<sub>50</sub> of 0.05 kPa. Over-estimation of p<sub>50</sub> at 0.4 kPa (3 mmHg) would imply significant (>17%) oxygen limitation of respiration under intracellular normoxia. Based on a critical review, we conclude that p<sub>50</sub> ranges from 0.01 to 0.10 kPa in mitochondria and small cells in the absence of inhibitors of cytochrome c oxidase, whereas experimental artefacts explain the controversial >200-fold range of p<sub>50</sub> in the literature on mitochondrial oxygen kinetics. | ||
|info=[http://www.ncbi.nlm.nih.gov/pubmed/20204766 PMID: 20204766] | |info=[http://www.ncbi.nlm.nih.gov/pubmed/20204766 PMID: 20204766] | ||
}} | }} | ||
Revision as of 13:38, 15 September 2010
| Scandurra FM, Gnaiger E (2010) Cell respiration under hypoxia: Facts and artefacts in mitochondrial oxygen kinetics. Adv. Exp. Med. Biol. 662: 7-25. |
Scandurra FM, Gnaiger E (2010) Adv. Exp. Med. Biol.
Abstract: When oxygen supply to tissues is limiting, mitochondrial respiration and ATP production are compromised. To assess the bioenergetic consequences under normoxia and hypoxia, quantitative evaluation of mitochondrial oxygen kinetics is required. Using high-resolution respirometry, the "apparent Km" for oxygen or p50 of respiration in 32D cells was determined at 0.05 +/- 0.01 kPa (0.4 mmHg, 0.5 µM, 0.25% air saturation). Close agreement with p50 of isolated mitochondria indicates that intracellular gradients are small in small cells at routine activity. At intracellular pO2 <2 kPa (15 mmHg, 10% air saturation) in various tissues under normoxia, respiration is limited by >2% with a p50 of 0.05 kPa. Over-estimation of p50 at 0.4 kPa (3 mmHg) would imply significant (>17%) oxygen limitation of respiration under intracellular normoxia. Based on a critical review, we conclude that p50 ranges from 0.01 to 0.10 kPa in mitochondria and small cells in the absence of inhibitors of cytochrome c oxidase, whereas experimental artefacts explain the controversial >200-fold range of p50 in the literature on mitochondrial oxygen kinetics.
• O2k-Network Lab: AT_Innsbruck_GnaigerE
Labels:
Stress:Hypoxia Organism: Mouse Tissue;cell: Blood Cell; Suspension Culture"Blood Cell; Suspension Culture" 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., Coupling; Membrane Potential"Coupling; Membrane Potential" 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, Method"Method" is not in the list (Oxygraph-2k, TIP2k, O2k-Fluorometer, pH, NO, TPP, Ca, O2k-Spectrophotometer, O2k-Manual, O2k-Protocol, ...) of allowed values for the "Instrument and method" property.
