Hydrogen Peroxide Production by Alveolar Macrophages Is
Increased and Its Concentration Is Elevated in the Breath of
Rats Exposed to Hypoxia: Relationship to Lung Lipid Peroxidation
J. WILHELM, M. VAŇKOVÁ1,
H. MAXOVÁ1, A. ŠIŠKOVÁ
Institute of Medical Chemistry and Biochemistry and 1Institute
of Pathological Physiology, Second Faculty of Medicine,
Charles University, Prague, Czech Republic
Received August 8, 2001
Accepted July 3, 2002
Summary
Hypoxic
exposure triggers a generation of reactive oxygen species that
initiate free radical damage to the lung. Hydrogen peroxide is
the product of alveolar macrophages detectable in the expired
breath. We evaluated the significance of breath H2O2
concentration for the assessment of lung damage after
hypoxic exposure and during posthypoxic period. Adult male rats
were exposed to normobaric hypoxia (10 % O2) for 3
hours or 5 days. Immediately after the hypoxic exposure and then
after 7 days or 14 days of air breathing, H2O2
was determined in the breath condensate and in isolated lung
macrophages. Lipid peroxidation was measured in lung homogenates.
Three-hour hypoxia did not cause immediate increase in the
breath H2O2; 5-day hypoxia increased
breath H2O2 level to 458 %. After 7 days
of subsequent air breathing H2O2 was
elevated in both groups exposed to hypoxia. Increased production
of H2O2 by macrophages was observed after
5 days of hypoxia and during the 7 days of subsequent air
breathing. Lipid peroxidation increased in the periods of
enhanced H2O2 generation by macrophages.
As the major increase (1040 %) in the breath H2O2
concentration found 7 days after 3 hours of hypoxia was
not accompanied by lipid peroxidation, it can be concluded that
the breath H2O2 is not a reliable
indicator of lung oxidative damage.
Key
words
Hydrogen peroxide • Alveolar macrophages • Lipid
peroxidation • Lung • Breath
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Dr. J. Wilhelm, Department of Medical Chemistry and
Biochemistry, Second Faculty of Medicine, Charles University
Plzeňská 221, 150 00 Prague, Czech Republic. E-mail:
jiri.wilhelm@lfmotol.cuni.cz
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