title: Hydrogen peroxide in the breath of rats: the effects of hypoxia and paraquat.
abstract: 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.
authors.affiliation: Department of Medical Chemistry and Biochemistry, Second Medical School, Charles University, Prague, Czech Republic. jiri.wilhelm@lfmotol.cuni.cz
authors.forename: J
authors.initials: J
authors.lastname: Wilhelm
authors.forename: M
authors.initials: M
authors.lastname: Frydrychová
authors.forename: M
authors.initials: M
authors.lastname: Vízek
mesh_terms: D000818:Animals; D006540:Herbicides / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000032:analysis / Q000378:metabolism*; D000860:Hypoxia / Q000378:metabolism*; D008168:Lung / Q000187:drug effects / Q000201:enzymology; D008297:Male; D019255:NADPH Oxidases / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D010269:Paraquat / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D006540:Herbicides; D006861:Hydrogen Peroxide; D019255:NADPH Oxidases; D010269:Paraquat