Comparative study of cell renewal after exposure to ozone or oxygen. Response of terminal bronchiolar epithelium in the rat
Cell renewal patterns of the terminal bronchiolar epithelium of rats were examined during 7-day exposures to either 0.8 ppM of ozone or 80% O/sub 2/. Terminal bronchiolar epithelial cells were classified and counted in ciliated, nonciliated secretory (Clara), and nonciliated, nonsecretory categories. Thymidine labeled with hydrogen-3 was used in conjunction with light microscopic autoradiography to obtain labeling indices in exposed rats at 6, 24, 72, and 168 hours compared to control rats at 6 and 168 hours. Results indicated that both ozone and O/sub 2/ initiated a proliferative response of terminal bronchiolar epithelium, but that the response to O/sub 2/ insult was delayed in onset and of lesser magnitude. Most importantly, the differential cell counts revealed that nonciliated secretory cells were the primary proliferating cell type at all periods after oxidant insult. This proliferative response continued with persistence of the insult through 168 hours. Shifts in proportions of cell types and labeling indices during exposure supported the view that nonciliated secretory cells are the reparative bronchiolar cells and that new ciliated cells are mainly derived from them.
- OSTI ID:
- 6526767
- Journal Information:
- Am. Rev. Respir. Dis.; (United States), Journal Name: Am. Rev. Respir. Dis.; (United States) Vol. 118:2; ISSN ARRDA
- 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 CELLS
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BODY
COMPARATIVE EVALUATIONS
ELECTRON MICROSCOPY
ELEMENTS
EPITHELIUM
HYDROGEN ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MAMMALS
MICROSCOPY
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
OXYGEN
OZONE
RADIOISOTOPES
RATS
RESPIRATORY TRACT CELLS
RODENTS
SENSITIVITY
TIME DEPENDENCE
TISSUES
TRACER TECHNIQUES
TRITIUM
VERTEBRATES
YEARS LIVING RADIOISOTOPES