MiPNet08.12 IOC22

Gnaiger E, Doeller JE, Kraus D, Shiva S, Brookes PS, Darley-Usmar VM (2003) NO effect on mitochondrial oxygen kinetics at low oxygen. Oxygraph-2k workshop Report. Mitochondr Physiol Network 08.12.

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OROBOROS (2003) Mitochondr Physiol Network

Abstract: [[has abstract::O2k-Protocol for NO effect on mitochondrial oxygen kinetics at low oxygen

A single pilot experiment was carried out during an Oxygraph-2k workshop on high-resolution respirometry (IOC22). Respiration of isolated rat liver mitochondria was inhibited by addition of NO, which increased the sensitivity to oxygen >25-fold when compared to the half-saturation oxygen pressure, p50, in the absence of NO. Oxygen kinetics followed a monophasic hyperbolic function up to 2.2 kPa with NO (p50=0.93 kPa), compared to the standard oxygen range to 1.1 kPa without NO (p50=0.035 kPa).

Figure 1. Oxygen dependence of mt-respiration and competitive inhibition by NO. The full line shows oxygen kinetics at state 3 with pyruvate and malate in the absence of NO, measured in the physiological oxygen range (from Gnaiger et al. 1998a). Dotted lines show inhibition of respiration by the indicated NO concentrations, where measurements were performed with low-resoltion respirometry and are restricted to the high oxygen range (from Koivisto et al. 1977). Extrapolations into the physiological oxygen range (shaded region) suggest sigmoidal oxygen kinetics, which requires testing by direct measurements at low oxygen (modified after Gnaiger, Kuznetsov 2002).

Reference: Biochim Biophys Acta 1797: 557-565 (2010)

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• O2k-Network Lab: AT_Innsbruck_OROBOROS, US_AL Birmingham_Kraus DW

Labels: MiParea: Respiration, Instruments;methods

Stress:Hypoxia, RONS; Oxidative Stress Organism: Rat Tissue;cell: Liver Preparation: Isolated Mitochondria

Regulation: Inhibitor, O2 Coupling state: OXPHOS

HRR: Oxygraph-2k, NO, Protocol

O2k-Demo