Effect of a Continuous Gamma Irradiation at a Very Low Dose on the Life Span of Mice
| Autor: | H Planel, C Caratero, L Bonnet, A Caratero, M. Courtade |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Aging
education.field_of_study Radiobiology business.industry Longevity Population Hormesis Physiology Dose-Response Relationship Radiation Biology Survival Analysis Ionizing radiation Mice Inbred C57BL Mice Dose–response relationship Gamma Rays Animals Female Irradiation Geriatrics and Gerontology Nuclear medicine business education Survival analysis Gamma irradiation |
| Zdroj: | Gerontology. 44:272-276 |
| ISSN: | 1423-0003 0304-324X |
| DOI: | 10.1159/000022024 |
| Popis: | Background: There is epidemiological evidence that suggests there are beneficial effects of ionizing radiation at low doses. Some experimental studies confirmed this hormetic effect with doses of about 1 cGy/day, but no data concerning very low dose rates are available. Objective: The aim of this study was to determine the life span of mice exposed to very low doses of ionizing radiation. Methods: Six hundred female C57BL/6 mice, 1 month old, were exposed to chronic gamma irradiation at very low dose rates of 7 or 14 cGy/year. These doses are about 25 or 50 times higher than background, but much lower than the doses of about 1 cGy/day used in previous experiments. Three hundred mice living in the same room were used as controls. Results: The life span, after the beginning of the experiment, determined by the survival time of 50% of each population, is increased in irradiated mice: 549 days in controls, 673 days in both irradiated groups. The differences are significant between the control and the irradiation mice. Differences between mice irradiated with 7 or 14 cGy are not significant. Conclusions: These results confirm the possibility of a nonharmful effect (hormesis) of ionizing radiation. They demonstrate that the paradigm, which states that low-dose effects can be predicted high-dose effects, cannot be systematically applied in radiation biology in general and gerontology in particular. |
| Databáze: | OpenAIRE |
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