著者

Sasaki Shunsaku Fukuda Nobuo

出版者

日本放射線影響学会

雑誌

Journal of radiation research (ISSN:04493060)

巻号頁・発行日

vol.49, no.6, pp.623-633, 2008-11-16

被引用文献数

3

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Female B6C3F1 mice were irradiated at day 17 prenatal period, day 0, 7, 35, 105, 240, 365 and 550 postnatal period with doses of 0.10 to 5.70Gy gamma rays from ^<137>Cs. All mice were allowed to live through their entire life spans under a specific-pathogen free condition. The excess relative risk for prevalence at the time of death of ovarian tumors was used as a comprehensive measure of radiation effect. The excess relative risks at 1Gy were estimated for all irradiated groups based on the dose-response relationships and compared to each other. A marked increase in susceptibility was found during the age between day 17 prenatal and day 0 postnatal period. A drastic decrease in susceptibility was observed during the period between day 105 and day 240. The shape of the dose-response curve was downward concave in mice irradiated at day 0, 7, 35 or 105 postnatal period, whereas, the downward curvature of dose-response was not observed in mice irradiated at day 17 prenatal period, day 240, 365 or 550 postnatal period. It has become obvious that mice of the early postnatal, pre-puberty and young adult periods are highly susceptible to induction of ovarian tumors by gamma rays.