[Monitoring of endogenous carbon monoxide elimination in exhaled air of rats in hyperoxia]

The authors offer a new method for continuous monitoring of endogenic carbon monoxide elimination in expired air of rats during inhalation of different oxygen mixtures. For the real-time CO detection at a 10 ppb level and at high CO2 and H2O concentrations the adjustable diode laser spectroscopy was used. Short intense peaks of CO in exhaled air after the onset of O2 inhalation was observed. The 60 min inhalation of 100% O2, 80% O2 and 60% O2 caused 44, 37 and 27% increases of endogenic CO as compared to initial concentrations, respectively. The duration of the effect of increased CO elimination had the tendency for a decrease with reduced concentrations of O2 in the inhaled gas mixture.