- high-resolution terminology - matching measurements at high-resolution
Residual oxygen consumption
Description
Residual oxygen consumption, ROX, is the respiration due to oxidative side reactions remaining after application of ETS inhibitors to mitochondrial preparations or cells, or in mt-preparations incubated without substrates (in the presence of ADP: State 2). ROX may be related to, but is different from ROS production.
Abbreviation: ROX
Reference: Gnaiger 2012 MitoPathways, Gnaiger_2008_POS, Gnaiger 2009 Int J Biochem Cell Biol
MitoPedia methods:
Respirometry
MitoPedia topics: "Respiratory state" is not in the list (Enzyme, Medium, Inhibitor, Substrate and metabolite, Uncoupler, Sample preparation, Permeabilization agent, EAGLE, MitoGlobal Organizations, MitoGlobal Centres, ...) of allowed values for the "MitoPedia topic" property.
Respiratory state"Respiratory state" is not in the list (Enzyme, Medium, Inhibitor, Substrate and metabolite, Uncoupler, Sample preparation, Permeabilization agent, EAGLE, MitoGlobal Organizations, MitoGlobal Centres, ...) of allowed values for the "MitoPedia topic" property.
1929: Residual respiration
'KCN, H2S and CO combine with some of the components of oxidase forming an inactive compound, with the result that cytochrome, or at least its components a’ and c’, as well as paraphenylenediamine added to the cells, are not oxidised. The respiratory process can be still carried out through the medium of some autoxidisable carriers such as haemochromogens, haematins, the component b’ of cytochrome, or some as yet unknown autoxidisable substances. This residual respiration, according to the nature of the cell, may represent a larger or smaller fraction of the total respiration of the cell' (Keilin 1929).
ROX and non-mitochondrial respiration
- Why 'State 2' but not 'non-mitochondrial respiration'?
Residual oxygen consumption (ROX) is sometimes referred to as 'non-mitochondrial respiration'. This may be correct to a large extent, but is not entirely accurate. In a preparation of purified isolated mitochondria, a small but significant ROX is observed, even after correction for instrumental background oxygen flux. In this case, ROX is 'mitochondrial non-ETS' rather than ‘non-mitochondrial’ respiration. In permeabilized and intact cells, ROX may be higher than in isolated mitochondria, and this increased part then would actually be the non-mitochondrial component of ROX.
