Modelling of mitochondrial oxygen consumption and NIRS detection of cytochrome oxidase redox state.
In recent years there has been widespread use of near infrared spectroscopy (NIRS) to monitor the brain. The signals of interest include changes in the levels of oxygenated and deoxygenated haemoglobin and tissue oxygen saturation. In addition to oxy- and deoxy-haemoglobin, the Cu(A) centre in cytochrome-c-oxidase (CCO) is a significant NIR absorber, giving rise to another signal termed the DeltaoxCCO signal. This signal has great potential as a marker of cellular oxygen metabolism, but is also the hardest to interpret. Here we use a recently constructed model to predict NIRS signal changes, and compare the model output to data from an in vivo hypoxia study in healthy adults. Our findings indicate strongly that the DeltaoxCCO signal contains useful information despite the noise, and has responses consistent with the known physiology.
Banaji
Murad
M
Department of Biological Sciences, University of Essex, Colchester CO4 3SQ, UK.
Mallet
Alfred
A
Elwell
Clare E
CE
Nicholls
Peter
P
Tachtsidis
Ilias
I
Smith
Martin
M
Cooper
Chris E
CE
D015687:Cell Hypoxia; D003576:Electron Transport Complex IV / Q000378:metabolism*; D006801:Humans; D008928:Mitochondria / Q000201:enzymology / Q000378:metabolism*; D008954:Models, Biological; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
D003576:Electron Transport Complex IV