Gnaiger 1995 J Bioenerg Biomembr

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Gnaiger E, Steinlechner-Maran R, Méndez G, Eberl T, Margreiter R (1995) Control of mitochondrial and cellular respiration by oxygen. J Bioenerg Biomembr 27:583-96.

» PMID: 8746845, Bioblast Access

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 in the LEAK state 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.

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: MiParea: Respiration, Instruments;methods Mammal;model: Human, Rat Tissue;cell: Liver, Endothelial;epithelial;mesothelial cell  Cell line: HUVEC Preparation: Intact cells, Isolated mitochondria Regulation: ADP, Flux control, Oxygen kinetics Coupling state: LEAK, ROUTINE, OXPHOS Substrate state: CI, CII HRR: Oxygraph-2k Additional: Made history 

High-resolution respirometry

  1. Gnaiger E, Steinlechner-Maran R, Méndez G, Eberl T, Margreiter R (1995) Control of mitochondrial and cellular respiration by oxygen. J Bioenerg Biomembr 27:583-96.
  2. Haller T, Ortner M, Gnaiger E (1994) A respirometer for investigating oxidative cell metabolism. Toward optimization of respiratory studies. Analyt Biochem 218:338-42. - »Bioblast link«
  3. Méndez G, Gnaiger E (1994) How does oxygen pressure control oxygen flux in isolated mitochondria? A methodological approach by high-resolution respirometry and digital data analysis. In: What is Controlling Life? (Gnaiger E, Gellerich FN, Wyss M, eds) Modern Trends in BioThermo-Kinetics 3. Innsbruck Univ Press:191-4. - »Bioblast link«
  4. Steinlechner-Maran R, Eberl T, Margreiter R, Gnaiger E (1994) Oxygen dependence of cellular respiration in endothelial cells: A sensitive toxicological test. In: What is Controlling Life? (Gnaiger E, Gellerich FN, Wyss M, eds) Modern Trends in BioThermo-Kinetics 3. Innsbruck Univ Press:283-7. - »Bioblast link«

Follow-up reviews on high-resolution respirometry

» More references: Instruments;methods

Follow-up reviews on mitochondrial and cellular oxygen kinetics

» More references: Oxygen kinetics

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