Changing sensitivity of neonatal rats to tumorigenic effects of N-nitroso-N-ethylurea and X-radiation, given singly or combined

Journal Article · Sun Mar 31 23:00:00 EST 1985 · J. Natl. Cancer Inst.; (United States)

OSTI ID:5123371

Knowles, J F

After neonatal injection of rats with 10 mg N-nitroso-N-ethylurea (ENU)/kg body weight, whole-body X-irradiation with 1.25 Gy X-radiation caused a reduction in induced neurogenic tumors which was dependent on the interval between the two treatments. The reduction was greatest when radiation was given 1 day after ENU and progressively decreased with irradiation at 5 and 30 days. Changes in radiosensitivity in the neonatal period were also seen for ovarian tumors and squamous cell carcinomas of the mouth. Ovarian tumors were induced by 1.25 Gy X-rays alone, with a higher incidence occurring after irradiation at 5 days than at 30 days of age. Squamous cell carcinomas of the mouth have a high spontaneous incidence in this strain of rat, but 1.25 Gy X-radiation caused a significant reduction which was greater after irradiation at 5 than at 30 days of age. Pituitary tumors occurred in untreated and treated rats with a higher incidence in females. Only in males was there any suggestion of an effect of the various treatments on pituitary tumor incidence.

• OSTI ID: 5123371
• Journal Information: J. Natl. Cancer Inst.; (United States), Journal Name: J. Natl. Cancer Inst.; (United States) Vol. 4; ISSN JNCIA
• Country of Publication: United States
• Language: English

Related Subjects

560152* -- Radiation Effects on Animals-- Animals
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
CARCINOMAS
DISEASES
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
MAMMALS
NEONATES
NEOPLASMS
NITROSO COMPOUNDS
NITROSOUREAS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADIATIONS
RADIOINDUCTION
RADIOSENSITIVITY EFFECTS
RATS
RODENTS
VERTEBRATES
X RADIATION