ACCELERATED TUMOR INCIDENCE IN RATS FOLLOWING CHRONIC GAMMA OR NEUTRON EXPOSURES

Technical Report · Fri May 01 04:00:00 EDT 1959

OSTI ID:4223990

Hartwig, Q L; Riess, R W; Wilson, Jr, S G

Two groups of female Sprague-Dawley rats were chronically exposed to ionizing radiation. One group was exposed to a total dose of 38 rep of fast neutrons over a period of 138 days; the other to 1,540 r of Co/supo 50 gamma rays over a period of 188 days. Irradiated animals and controls were observed for tumor production. All of the surviving rats of the 1,540 r group were sacrificed 613 days following the first exposure. Forty-six per cent of the irradiated rats developed one or more tumors and 18 per cent of the controls had a tumor. Twenty- nine per cent of the mammary tumors in the irradiated animals were malignant compared to 11 per cent in the controls. A similar increase in malignancy existed in the nonmammary tumors. All of the surviving rats of the 38 rep group were sacrificed 420 days following the first exposure. At termination of the experiment, 35 per cent of the irradiated rats had tumors as compared to 10 per cent of the controls. Thirteen per cent of the exposed animals possessed a malignant mammary tumor but none existed in the controls. As outlined in this experiment, it is postulated that ionizing radiation not only accelerates the appearance of tumors but also favors an early appearance of malignant tumors. (auth)

• Research Organization: School of Aviation Medicine, Brooks AFB, Tex.; and Texas. Univ., Austin
• NSA Number: NSA-14-004208
• OSTI ID: 4223990
• Report Number(s): AF-SAM-59-88
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BIOLOGY AND MEDICINE
CANCER
CARCINOGENESIS
COBALT 60
GAMMA RADIATION
GLANDS
MAMMARY GLANDS
NEUTRONS
RADIATION DOSES
RADIATION INJURIES
RATS
SEX
TUMORS