Takeda H, Fuma S, Miyamoto K, Kuroda N, Inaba J
National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba-shi, 263 Japan.
Radiat Prot Dosimetry. 2003;105(1-4):291-6. doi: 10.1093/oxfordjournals.rpd.a006243.
The transfer of 14C through placenta or milk was investigated and the radiation dose to fetal and newborn rats was estimated. Female rats at different gestational stages or after delivery were exposed to 14C in the form of sodium bicarbonate, thymidine and lysine by a single ingestion. Radioactivity in maternal tissues and conceptuses (placenta, fetal membrane and fetus) and in the newborn was determined at various times after ingestion. After exposure to these 14C compounds, there was no significant difference between the 14C concentration in the fetus and that in the maternal tissues, suggesting that the placenta has no effect in preventing or accelerating the placental transfer of 14C. The concentration and content of 14C in the fetus and newborn were, however, dependent on the chemical form of 14C and on the prenatal or neonatal stage at the time of ingestion. The result of the dose estimation showed that 14C-lysine gave significantly higher prenatal and neonatal doses than 14C-sodium bicarbonate or 14C-thymidine.
研究了¹⁴C通过胎盘或乳汁的转移情况，并估算了对胎鼠和新生鼠的辐射剂量。处于不同妊娠阶段或产后的雌性大鼠通过单次摄入以碳酸氢钠、胸腺嘧啶核苷和赖氨酸形式存在的¹⁴C。在摄入后的不同时间测定母体组织和孕体（胎盘、胎膜和胎儿）以及新生鼠体内的放射性。暴露于这些¹⁴C化合物后，胎儿体内的¹⁴C浓度与母体组织中的¹⁴C浓度之间无显著差异，这表明胎盘对¹⁴C的胎盘转移没有预防或加速作用。然而，胎儿和新生鼠体内¹⁴C的浓度和含量取决于¹⁴C的化学形式以及摄入时的产前或新生儿阶段。剂量估算结果表明，¹⁴C-赖氨酸产生的产前和新生儿剂量显著高于¹⁴C-碳酸氢钠或¹⁴C-胸腺嘧啶核苷。
