Olsen I, Jonsen J
Acta Pharmacol Toxicol (Copenh). 1979 Jan;44(1):22-7. doi: 10.1111/j.1600-0773.1979.tb02290.x.
90Sr is a hazardous fission product from nuclear reactions. Its transplacental passage is of particular interest because of the high sensitivity of embryos/foetuses to ionizing radiation. We have used whole-body autoradiography to study the foetal uptake and retention of 90Sr and the embryonic/foetal transfer of this isotope as a function of gestational age. Fifteen minutes after an intraperitoneal injection of 50 muci 90Sr-nitrate into a 14-day-pregnant mouse, radioactivity was present in the placenta, but not in the foetus. During a 72-hour observation period, 90Sr gradually accumulated in the hard foetal tissues. In the soft foetal tissues, accumulation occurred up to 12--24 hours. After 72 hours, no 90Sr could be detected in the soft tissues. 90Sr crossed the visceral yolk sac placenta during early gestation, the visceral yolk sac and the chorioallantoic placentas during late gestation. Transfer increased considerably at the end of the latter period. There was a marked uptake of 90Sr in all structures of early embryos, whereas the isotope concentrated in the preskeletal and skeletal parts of the foetuses. Intake of 90Sr during early gestation may therefore be more injurious to the offspring than intake during late gestation.
90锶是核反应产生的一种有害裂变产物。由于胚胎/胎儿对电离辐射高度敏感，其经胎盘转运尤其受到关注。我们利用全身放射自显影技术研究了90锶在胎儿体内的摄取和滞留情况，以及该同位素在胚胎/胎儿体内的转运与胎龄的关系。给怀孕14天的小鼠腹腔注射50微居里的硝酸90锶15分钟后，胎盘内有放射性，但胎儿体内没有。在72小时的观察期内，90锶逐渐在胎儿的硬组织中蓄积。在胎儿的软组织中，蓄积可持续12至24小时。72小时后，软组织中检测不到90锶。90锶在妊娠早期穿过脏层卵黄囊胎盘，在妊娠晚期穿过脏层卵黄囊和绒毛膜尿囊胎盘。在妊娠晚期结束时，转运量大幅增加。早期胚胎的所有结构中都有明显的90锶摄取，而该同位素则集中在胎儿的骨骼前和骨骼部分。因此，妊娠早期摄入90锶可能比妊娠晚期摄入对后代的危害更大。
