Scandurra 2010 Adv Exp Med Biol: Difference between revisions
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{{Publication | {{Publication | ||
|title=Scandurra FM, Gnaiger E (2010) Cell respiration under hypoxia: Facts and artefacts in mitochondrial oxygen kinetics. Adv | |title=Scandurra FM, Gnaiger E (2010) Cell respiration under hypoxia: Facts and artefacts in mitochondrial oxygen kinetics. Adv Exp Med Biol 662: 7-25. | ||
|info=[http://www.ncbi.nlm.nih.gov/pubmed/20204766 PMID: 20204766] | |info=[http://www.ncbi.nlm.nih.gov/pubmed/20204766 PMID: 20204766] | ||
|authors=Scandurra FM, Gnaiger E | |authors=Scandurra FM, Gnaiger E | ||
|year=2010 | |year=2010 | ||
|journal=Adv | |journal=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 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. | |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. | ||
|mipnetlab=AT_Innsbruck_Gnaiger E | |mipnetlab=AT_Innsbruck_Gnaiger E | ||
Revision as of 19:53, 21 November 2011
| Scandurra FM, Gnaiger E (2010) Cell respiration under hypoxia: Facts and artefacts in mitochondrial oxygen kinetics. Adv Exp Med Biol 662: 7-25. |
» [[Has info::PMID: 20204766]]
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_Gnaiger E
Labels:
Stress:Hypoxia Organism: Mouse Tissue;cell: Blood Cell; Suspension Culture Preparation: Intact Cell; Cultured; Primary, Isolated Mitochondria
Regulation: Respiration; OXPHOS; ETS Capacity, Coupling; Membrane Potential
HRR: Oxygraph-2k
Instrumental and methodological aspects
