Biological Effects of Tritium Radiation Quantitatively Estimated Using Mouse Fetal Cell Damage

利用小鼠胎儿细胞损伤定量估计氚辐射的生物学效应

• 批准号: 08680539
• 负责人: YAMADA Takeshi
• 金额: $ 1.09万
• 依托单位: Toho University School of Medicine
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08680539/
• 关键词: Radiation effects; beta-rays; Mice; Fetal development; Role of apoptosis; RBE; B線; RBF; 放射線

Effects of beta-radiation from 4 kinds of organically bound tritium compounds (OBTs) including methyl-^3H-thymidine were investigated on cultured mouse embryonic mid brain cells (MBC). The relative biological effectiveness (RBE) values, ranging from 4.6 to 8.7, of beta ray from OBTs were obtained when compared with X-irradiation at their ID5Os (50 % inhibiton dose) on the inhibition of cell proliferation and differentiation, and on the decrease of DNA and protein contents of the cultures. Doses as low as 5 cGy from a mixed exposure resulted in detectable inhibitory effects.Induction of apoptosis by tritium exposure was investigated in both MBC and brain sections of embryos and of newborns in mice. In the cultures of MBC, addition of methyl-^3H-thymidine (^3H-TdR) (21 kBq ml^<-1>) and tritiated water (HTO) (5.616 MBq ml^<-1>) induced late appearances and low percentages of apoptosis when compared to X-irradiation at the ID50 dose. The pregnant mice were given an intraperitoneal injection of HTO at the concentration of 481.8 kBq g^<-1> of body weight on gestation day 12.5, by which treatment behavioral changes in the offspring occurred. Increased apoptotic cells were observed in the neural tube of embryos from 1 day after the injection to 1 week postnatal age. Apoptosis induced by X-rays appeared 2 h after irradiation, with a peak at 4 h. Increase of apoptotic cells was also found in the brain cortexes of newborns. The percentage of apoptosis in the brain was higher in the prenatal HTO exposed mice than in the prenatal X-irradiated mice. Possible mechanisms on apoptosis and its relation to the higher relative biological effectiveness (RBE) value of tritium beta-rays are discussed.

研究了包括甲基-^3H-胸苷在内的 4 种有机结合氚化合物 (OBT) 的 β 辐射对培养的小鼠胚胎中脑细胞 (MBC) 的影响。与 ID5Os（50% 抑制剂量）的 X 射线照射相比，OBT 的 β 射线对细胞增殖和分化的抑制以及细胞增殖和分化的抑制作用的相对生物有效性（RBE）值范围为 4.6 至 8.7。培养物的 DNA 和蛋白质含量。混合暴露的低至 5 cGy 的剂量会产生可检测到的抑制作用。在小鼠胚胎和新生儿的 MBC 和脑切片中研究了氚暴露对细胞凋亡的诱导。在MBC培养物中，添加甲基-^3H-胸苷(^3H-TdR)(21kBqml^-1>)和氚化水(HTO)(5.616MBqml^-1>)诱导延迟出现和与 ID50 剂量的 X 射线照射相比，细胞凋亡百分比较低。在妊娠第12.5天，对妊娠小鼠进行腹腔注射HTO，浓度为481.8kBq g^ -1 体重，通过这种治疗，子代发生了行为变化。从注射后1天到出生后1周，在胚胎神经管中观察到凋亡细胞增加。 X射线诱导的细胞凋亡在照射后2小时出现，4小时达到峰值。在新生儿的大脑皮层中也发现了凋亡细胞的增加。产前 HTO 暴露小鼠的脑细胞凋亡百分比高于产前 X 射线照射的小鼠。讨论了细胞凋亡的可能机制及其与氚β射线较高的相对生物有效性（RBE）值的关系。

项目成果

Wang,B., Yamada,T. et al.: "Induction of apoptosis in cultured midbrain cells from embyronic mice" Radiation Research. 143. 304-308 (1997)

王B.，山田T.

Wang B,Watanabe K,Yamada T,Shima A.: "Induction of apoptosis in cultured midbrain cells from embyronic mice." Radiation Res. 143. 304-308 (1997)

Wang B、Watanabe K、Yamada T、Shima A.：“诱导胚胎小鼠培养的中脑细胞凋亡。”

Wang B, Yamada T.et al.: "Radiation-Induced Apoptosis Responsible for Limb Teratogenesis of Embryonic Mice" Radiat.Res.151. 63-68 (1999)

Wang B、Yamada T.et al.：“辐射诱导的细胞凋亡负责胚胎小鼠肢体畸形”Radiat.Res.151。

Wang B, Yamada T.et al.: "Effects of β radiation from organically bound tritium on the cultured mouse embryonic mid brain cells." Health Physics. 71. 913-919 (1996)

Wang B, Yamada T.et al.：“有机结合氚的 β 辐射对培养的小鼠胚胎中脑细胞的影响。” 71. 913-919 (1996)

Wang B, Yamada T.et al.: "Induction of apoptosis in cultured midbrain cells from embyronic mice." Radiation Res.143. 304-308 (1997)

Wang B、Yamada T.et al.：“诱导胚胎小鼠培养的中脑细胞凋亡。”