| First Author | Caratero A | Year | 1998 |
| Journal | Gerontology | Volume | 44 |
| Issue | 5 | Pages | 272-6 |
| PubMed ID | 9693258 | Mgi Jnum | J:49634 |
| Mgi Id | MGI:1277775 | Doi | 10.1159/000022024 |
| Citation | Caratero A, et al. (1998) Effect of a continuous gamma irradiation at a very low dose on the life span of mice. Gerontology 44(5):272-6 |
| abstractText | 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. |
