Response of the rat tracheal epithelium to ozone exposure. Injury, adaptation, and repair
Although acute ozone (O/sub 3/) exposure injures tracheal epithelium, the response of the tracheal epithelium to prolonged O/sub 3/ exposure, and the degree of repair following cessation of exposure have not been previously reported. The purpose of this experiment was to characterize the morphologic response of rat tracheal epithelium to acute (3 days) and prolonged (60 days) exposure to 0.96 ppm O/sub 3/ as well as to evaluate repair in a 7- and 42-day post-60-day exposure period. Quantitative light- and electron-microscopic evaluation and thymidine labeling indices showed that after 3 days of O/sub 3/ exposure there was ciliary damage, cell necrosis, an increased density of intermediate cells, and an elevated thymidine labeling index. Following 60 days of exposure, the only major change from controls was the presence of ciliated cells with uniformly short cilia. Tracheal superoxide dismutase levels did not differ between control and 60-day exposure groups. Our findings suggest that the tracheal epithelium adapts to prolonged ozone exposure with the exception of cilia formation in ciliated cells. Complete epithelial recovery occurred by 42 days after exposure.
- Research Organization:
- Univ. of California, Davis (USA)
- OSTI ID:
- 7024775
- Journal Information:
- Am. J. Pathol.; (United States), Journal Name: Am. J. Pathol.; (United States) Vol. 131:2; ISSN AJPAA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL TISSUES
ANIMALS
AZINES
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BIOSYNTHESIS
BODY
ELECTRON MICROSCOPY
ENZYMES
EPITHELIUM
HETEROCYCLIC COMPOUNDS
MAMMALS
MICROSCOPY
MORPHOLOGICAL CHANGES
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDOREDUCTASES
OZONE
PYRIMIDINES
RATS
RECOVERY
REPAIR
RESPIRATORY SYSTEM
RIBOSIDES
RODENTS
SUPEROXIDE DISMUTASE
SYNTHESIS
THYMIDINE
TISSUES
TOXICITY
TRACHEA
VERTEBRATES