CO2 exacerbates oxygen toxicity
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Updated: Jun 4, 2026

Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department
Published on: January 29, 2011
Benjamin Ezraty1, Maïalène Chabalier, Adrien Ducret
1Aix Marseille Université, Laboratoire de Chimie Bactérienne (UPR 9043), Institut de Microbiologie de la Méditerranée (IFR88), CNRS, 31, Chemin Joseph Aiguier, 13402 Marseille, France.
Abstract:
Reactive oxygen species (ROS) are harmful because they can oxidize biological macromolecules. We show here that atmospheric CO(2) (concentration range studied: 40-1,000 p.p.m.) increases death rates due to H(2)O(2) stress in Escherichia coli in a dose-specific manner. This effect is correlated with an increase in H(2)O(2)-induced mutagenesis and, as shown by 8-oxo-guanine determinations in cells, DNA base oxidation rates. Moreover, the survival of mutants that are sensitive to aerobic conditions (Hpx(-) dps and recA fur), presumably because of their inability to tolerate ROS, seems to depend on CO(2) concentration. Thus, CO(2) exacerbates ROS toxicity by increasing oxidative cellular lesions.
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