Accession Number:

AD0422739

Title:

THE EFFECT OF AGE AT IRRADIATION UPON LIFESPAN IN THE MALE RAT,

Descriptive Note:

Corporate Author:

NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CALIF

Personal Author(s):

Report Date:

1963-09-10

Pagination or Media Count:

23.0

Abstract:

Male rats average numbergroup equal 127 were exposed to a single whole-body high sublethal 30 day dose of fast neutrons 220 plus or minus 10 rads at one of five ages ranging from the juvenile to the late adult stages of life. Lifespan functions for these groups were compared with those of littermate controls. For nonirradiated control groups of this SpragueDawley strain the median lifespan was 703 days S. D. equals 41 days. In terms of the median or mean survival time, life expectancy, agespecific death rate, and survival curve, there was a marked detrimental effect of irradiation in animals exposed at one month of age. This radiation effect diminished progressively when exposure occurred at 3 or 10 months of age, and was no longer discernible in groups exposed at 15 or 21 months. For those age groups 1, 3, or 10 months which exhibited a significant alteration in lifespan functions, there was a latent period of seven to ten months before the effect became apparent. It appears that age at exposure is an important stipulation for consideration of longterm effects of irradiation. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE