Application of the EPR spin-trapping technique to the detection of radicals produced in vivo during inhalation exposure of rats to ozone
- Laboratory of Molecular Biophysics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC (United States)
Ozone is known to induce lipid peroxidation of lung tissue, although no direct evidence of free radical formation has been reported. We have used the electron paramagnetic resonance (EPR) spin-trapping technique to search for free radicals produced in vivo by ozone exposure. The spin trap alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN) was administered ip to male Sprague-Dawley rats. The rats were then exposed for 2 hr to either 0, 0.5, 1.0, 1.5, or 2.0 ppm ozone with 8% CO2 to increase their respiratory rate. A six-line 4-POBN/radical spin adduct signal (aN = 15.02 G and a beta H = 3.27 G) was detected by EPR spectroscopy in lipid extracts from lungs of rats treated with 4-POBN and then exposed to ozone. Only a weak signal was observed in the corresponding solution from rats exposed to 0 ppm ozone (air with CO2 only). The concentration of the radical adduct increased as a function of ozone concentration. After administration of 4-POBN, rats were exposed for either 0.5, 1.0, 2.0, or 4.0 hr to either 0 or 2.0 ppm ozone (with CO2). The radical adduct concentration of the ozone-exposed groups at exposure times of 2.0 and 4.0 hr was significantly different from that of the corresponding air control groups. A correlation was observed between the radical adduct concentration and the lung weight/body weight ratio. These results demonstrate that ozone induces the production of free radicals in rat lungs during inhalation exposure and that radical production may be involved in the induction of pulmonary toxicity by ozone. This is the first direct evidence for ozone-induced free radical production in vivo.
- OSTI ID:
- 5263686
- Journal Information:
- Toxicology and Applied Pharmacology; (United States), Journal Name: Toxicology and Applied Pharmacology; (United States) Vol. 114:1; ISSN TXAPA; ISSN 0041-008X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Application of the EPR spin-trapping technique to the detection of radicals produced in vivo during inhalation exposure of rats to ozone
Use of epr spin-trapping techniques to detect radicals from rat lung lavage fluid following sulfur mustard vapor exposure
Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL MATERIALS
BIOSYNTHESIS
BODY
CHALCOGENIDES
ELECTRON SPIN RESONANCE
INHALATION
INTAKE
LUNGS
MAGNETIC RESONANCE
MAMMALS
MATERIALS
METABOLISM
NITROGEN COMPOUNDS
NITROGEN OXIDES
ORGANS
OXIDES
OXYGEN COMPOUNDS
OZONE
RADICALS
RATS
RESONANCE
RESPIRATORY SYSTEM
RODENTS
SENSITIVITY
SYNTHESIS
TISSUE EXTRACTS
TOXICITY
VERTEBRATES