Inhibition of mouse lung tumor development by hyperoxia

Journal Article · Tue Apr 01 04:00:00 EST 1986 · Cancer Res.; (United States)

OSTI ID:5674451

Lindenschmidt, R C; Tryka, A F; Witschi, H P

The hypothesis was tested that continuous hyperoxia would enhance the development of lung tumors in mice. In strain A/J mice treated with a single dose of urethan (1000 mg/kg) and exposed to 70% O2 for 16 wk, an average of 5 tumors per lung developed, whereas in animals kept in air, an average of 20 tumors per lung was found. When the animals were returned to air after oxygen exposure, it was found that a difference of 15 tumors per lung between the two groups persisted up to 1 yr later, indicating that O2 was tumoricidal. The shortest duration of O2 exposure to be effective was 4 wk, and delay of O2 exposure up to 12 wk after urethan still was effective in reducing the number of developing tumors. Histopathology showed that continued exposure to 70% O2 produced some hyperplasia of the bronchiolar epithelium and only very discrete changes in the pulmonary parenchyma. Analysis of cell proliferation patterns with a continuous (3H)thymidine labeling technique showed a persistent high cell labeling in the bronchiolar epithelium and a temporary increase in alveolar wall cell labeling. Chronic hyperoxia failed to alter the activities of pulmonary superoxide dismutase or glucose-6-phosphate dehydrogenase. Ornithine decarboxylase, on the other hand, was increased as long as the animals remained exposed to oxygen. It was concluded that hyperoxia kills developing tumor cells in mouse lung.

• Research Organization: Oak Ridge National Lab., TN
• OSTI ID: 5674451
• Journal Information: Cancer Res.; (United States), Journal Name: Cancer Res.; (United States); ISSN CNREA
• 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 EFFECTS
BODY
CARBAMATES
CARBONIC ACID DERIVATIVES
CARBOXYLIC ACID SALTS
CELL DIVISION
DISEASES
ELEMENTS
HETEROCYCLIC COMPOUNDS
INHIBITION
LABELLED COMPOUNDS
LUNGS
MAMMALS
MICE
NEOPLASMS
NONMETALS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OXYGEN
PYRIMIDINES
RESPIRATORY SYSTEM
RIBOSIDES
RODENTS
THYMIDINE
TOXICITY
TRITIUM COMPOUNDS
URETHANE
VERTEBRATES