Morgan A, Haines J W, Harrison J D
National Radiological Protection Board, Chilton, Didcot, Oxon, UK.
Int J Radiat Biol. 1991 Jun;59(6):1395-413. doi: 10.1080/09553009114551251.
The transfer of 238Pu from the maternal circulation to the developing embryo and fetus was studied in rats and guinea-pigs to provide data for the development of dosimetric models for the human embryo and fetus. Following administration at different stages of gestation, measurements were made after 3 days in the rat and 7 days in guinea-pigs. The amount transferred was greater after administration at later stages of gestation, up to a maximum of about 0.8-0.9% of the injected activity per fetoplacental unit (FPU) and about 0.2% per fetus in both species. In advanced gestation the yolk sac, the initial site of haemopoietic stem cells, contained up to 80% of the total activity in the FPU in rats, compared with about 25% for the guinea-pig; retention in placental trophoblast was greater in the guinea-pig. The concentrations of 238Pu in the yolk sac were generally about two to three orders of magnitude greater than fetal concentrations and of the same order as in maternal liver and bone. In both species, concentrations in the embryo and fetus were greatest after injection early in gestation, reached their lowest around mid-organogenesis and increased again in later gestation. The fetus:mother whole-body concentration ratios in late gestation were about 0.1 and 0.05 in rats and guinea-pigs, respectively. Measurements were also made of the 238Pu retention in neonates at birth. In guinea-pigs the liver accounted for about 6-9% of retained activity; similar values for femora indicated skeletal retention of about 60-80%. For administration at each stage of gestation, and particularly at early stages, transfer of 238Pu to the fetus continued throughout gestation but concentrations decreased due to fetal growth.
在大鼠和豚鼠中研究了238Pu从母体循环向发育中的胚胎和胎儿的转移，以提供数据用于建立人类胚胎和胎儿的剂量学模型。在妊娠不同阶段给药后，分别在大鼠给药3天后和豚鼠给药7天后进行测量。在妊娠后期给药后转移的量更大，在两个物种中，每个胎儿-胎盘单位（FPU）转移的量最高可达注射活度的约0.8 - 0.9%，每个胎儿约为0.2%。在妊娠晚期，造血干细胞的初始位点卵黄囊中，大鼠FPU中的总活度含量高达80%，而豚鼠约为25%；豚鼠胎盘滋养层中的滞留量更大。卵黄囊中238Pu的浓度通常比胎儿浓度高约两到三个数量级，与母体肝脏和骨骼中的浓度处于同一数量级。在两个物种中，胚胎和胎儿中的浓度在妊娠早期注射后最高，在器官发生中期左右达到最低，在妊娠后期又再次升高。妊娠晚期胎儿与母体全身浓度比在大鼠和豚鼠中分别约为0.1和0.05。还对出生时新生儿体内238Pu的滞留情况进行了测量。在豚鼠中，肝脏占滞留活度的约6 - 9%；股骨的类似数值表明骨骼滞留约为60 - 80%。对于妊娠各阶段给药，特别是早期给药，238Pu向胎儿的转移在整个妊娠期间持续进行，但由于胎儿生长，浓度会降低。
