Hydrogen peroxide in the breath of rats: the effects of hypoxia and paraquat

Physiol Res. 1999;48(6):445-9.


The hypothesis that oxidative stress can be induced by hypoxia was tested by measuring the concentration of hydrogen peroxide by a luminometric technique in the breath samples of rats exposed to hypoxia and paraquat. The group of animals (n=15) exposed to normobaric hypoxia (10% O2) for three days had an increased amount of H2O2 (200%, P<0.001) in their breath in comparison to control animals. After 7 days of recovery in air, the exposed animals still produced significantly increased levels of H2O2 (152%, P<0.001). Paraquat administration was used as a positive control, since it is a redox cycling compound producing free radicals. In the animals treated with a toxic dose of paraquat, the peak H2O2 production was observed 5 h after i.p. injection (156%, P<0.02). Within the next 2 h it decreased to the control level and stayed constant for 48 h, when the animals began to die. It is suggested that H2O2, observed in the breath samples, is a product of a metabolic pathway that could itself be sensitive to oxidative damage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Herbicides / pharmacology*
  • Hydrogen Peroxide / analysis
  • Hydrogen Peroxide / metabolism*
  • Hypoxia / metabolism*
  • Lung / drug effects
  • Lung / enzymology
  • Male
  • NADPH Oxidases / metabolism
  • Oxidative Stress / drug effects*
  • Oxidative Stress / physiology
  • Paraquat / pharmacology*
  • Rats
  • Rats, Wistar


  • Herbicides
  • Hydrogen Peroxide
  • NADPH Oxidases
  • Paraquat