Short-term effect of single and combined exposures to nitrogen dioxide and ozone on DNA synthesis and cell proliferation in rat lungs

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5598634

Giliberto, A A

Approximately three month old male Sprague-Dawley rats, free of specific pathogens, were exposed to either 1.8 ppm nitrogen dioxide (NO{sub 2}) or 0.45 ppm ozone (O{sub 3}) or to a combination of both of these gases. The time-course of oxidant exposure showed that for all exposure regimens, incorporation of tritated-thymidine into rat lung DNA peaked at forty-eight hours of continuous exposure and declined by seventy-two hours of exposure. The injury-repair curves for the O{sub 3} exposure and the combined exposure groups were similar. The labeling indexes (LI) for the terminal bronchioles, the alveolar type 2 cells, and all other alveolar interstitial cells at forty-eight hours of exposure demonstrated that the magnitude of alveolar epithelial injury was significantly greater when O{sub 3} was present. After forty-eight hours of exposure NO{sub 2} alone did not produce a measurable acute inflammatory response. The LI for the pulmonary alveolar macrophages suggests that there maybe in in-situ proliferation of these cells in response to oxidant exposure. There was a highly significant influx of neutrophils and an elevated protein content of cell-free lavage fluids indicative of an acute inflammatory response for the O{sub 3} exposed and the combined exposure groups.

• Research Organization: California Univ., Los Angeles, CA (USA)
• OSTI ID: 5598634
• Country of Publication: United States
• Language: English

Related Subjects

550501 -- Metabolism-- Tracer Techniques
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
AZINES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY
BODY FLUIDS
CELL PROLIFERATION
CHALCOGENIDES
CONNECTIVE TISSUE CELLS
DNA REPLICATION
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
LEUKOCYTES
LUNGS
MACROPHAGES
MAMMALS
MATERIALS
NEUTROPHILS
NITROGEN COMPOUNDS
NITROGEN DIOXIDE
NITROGEN OXIDES
NUCLEIC ACID REPLICATION
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OXIDES
OXYGEN COMPOUNDS
OZONE
PATHOLOGICAL CHANGES
PHAGOCYTES
PYRIMIDINES
RATS
RESPIRATORY SYSTEM
RIBOSIDES
RODENTS
SOMATIC CELLS
SYNERGISM
THYMIDINE
TOXICITY
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES