Scandurra 2010 Adv Exp Med Biol

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 K (m)" for oxygen or p (50) of respiration in 32D cells was determined at 0.05 +/- 0.01 kPa (0.4 mmHg, 0.5 microM, 0.25% air saturation). Close agreement with p (50) of isolated mitochondria indicates that intracellular gradients are small in small cells at routine activity. At intracellular p (O2) <2 kPa (15 mmHg, 10% air saturation) in various tissues under normoxia, respiration is limited by >2% with a p (50) of 0.05 kPa. Over-estimation of p (50) 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 (50) 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 (50) in the literature on mitochondrial oxygen kinetics.

• O2k-Network Lab: AT_Innsbruck_GnaigerE

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, Method