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标题：Micronuclei Induced by Low Dose Rate Irradiation in Early Spermatids of p53 Null and Wild Mice
其他标题：Micronuclei Induced by Low Dose Rate Irradiation in Early Spermatids of p53 Null and Wild Mice
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作者：NAOKI KUNUGITA ; HIROYO KAKIHARA ; TOSHIHIRO KAWAMOTO 等
期刊名称：Journal of Radiation Research
印刷版ISSN：0449-3060
电子版ISSN：1349-9157
出版年度：2002
卷号：43
期号：S
页码：205-207
DOI：10.1269/jrr.43.S205
摘要：To obtain evidence of the dose-rate effect on induction of micronuclei in early spermatids, we observed frequencies in wild-type p53 ( / ), heterozygous p53 ( /-) and null p53 (-/-) mice 14 days after gamma rays irradiation at a high (1,020 mGy/min) or a low (1.2 mGy/min) dose-rate. A dose- and dose-rate-related increase in micronuclei was seen in early spermatids with no difference between the different p53 status. These data were found to be best fitted by a linear-quadratic dose-response model at a high dose-rate, and by a linear dose-response model at a low dose-rate. The yields at 1.2 mGy/min were significantly lower than those at 1,020 mGy/min in the same manner, independent of p53 status. Testis weight declined significantly after 3 Gy irradiation, but did not depend on dose-rates. In our other studies, we observed the complete elimination both of malformation in fetuses and CD3 - 4 mutant T-lymphocytes in p53 ( / ) mice, but not in p53 (-/-) mice after irradiation. This indicates that concerted DNA repair and p53-dependent apoptosis are likely to completely eliminate mutagenic damage from the irradiated tissues at low doses or dose-rates in teratogenesis and lymphocytes. In the germ cell, however, irradiation at 1.2 mGy/min was mutagenic, independent of p53 status.
关键词：Micronucleus; Spermatid; p53; Radiation; Dose-rate effect