Pulmonary NO/sub 2/ toxicity: phosphatidylcholine levels and incorporation of (/sup 3/H)thymidine into DNA

Journal Article · Thu Apr 01 04:00:00 EST 1982 · Environ. Res.; (United States)

OSTI ID:5528140

Blank, M L ^[1]; Dalbey, W; Cress, E A; Garfinkel, S; Snyder, F

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1. Oak Ridge Associated Universities, TN

Lungs from rats exposed to 30 ppm NO/sub 2/ (..mu..l/liter) for either 1 or 5 hr had higher incorporation rates of (/sup 3/H)thymidine into DNA and greater amounts of phosphatidylcholine than the lungs from control animals. Although there was no difference between the pulmonary phosphatidylcholine levels in rats exposed to NO/sub 2/ for 1 or 5 hr, the incorporation of (/sup 3/H)thymidine into DNA was considerably higher in the lungs of animals exposed to NO/sub 2/ for 5 hr than in those exposed for 1 hr. Analyses of autoradiograms of lung tissue showed essentially the same labeling index for the alveoli from animals exposed to NO/sub 2/ for 1 or 5 hr; however, the animals exposed to NO/sub 2/ for 5 hr had a greater number of labeled cells in the lower airways and alveolar ducts than in the lungs from rats exposed for only 1 hr. These results suggest that the increased levels of phosphatidylcholine after exposure to NO/sub 2/ are directly related to damage of the alveolar cells, whereas the incorporation of (/sup 3/H)thymidine into lung DNA represents more widespread damage to areas involving the lower airways. Second and third exposures (24 hr apart) of rats to 30 ppm NO/sub 2/ for either 1 or 5 hr caused little increase in the incorporation of (/sup 3/H)thymidine into pulmomary DNA and no further increase in lung phosphatidylcholine levels. Decreased incorporation of thymidine into the DNA of pulmonary cells after second and third exposures to NO/sub 2/ is referred to as ''adaptation'' in this report. When NO/sub 2/-adapted animals were again exposed to NO/sub 2/ 7 days after the previous NO/sub 2/ treatment, the lungs again exhibited increases in both (/sup 3/)thymidine incorporation and levels of phosphatidylcholine.

• OSTI ID: 5528140
• Journal Information: Environ. Res.; (United States), Journal Name: Environ. Res.; (United States) Vol. 27:2; ISSN ENVRA
• Country of Publication: United States
• Language: English

Related Subjects

560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
AZINES
BIOLOGICAL ADAPTATION
BIOLOGICAL EFFECTS
BODY
CHALCOGENIDES
DNA
ESTERS
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIPIDS
LUNGS
MAMMALS
NITROGEN COMPOUNDS
NITROGEN DIOXIDE
NITROGEN OXIDES
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANS
OXIDES
OXYGEN COMPOUNDS
PHOSPHOLIPIDS
PYRIMIDINES
QUANTITY RATIO
RATS
RESPIRATORY SYSTEM
RIBOSIDES
RODENTS
THYMIDINE
TRACER TECHNIQUES
TRITIUM COMPOUNDS
UPTAKE
VERTEBRATES