Pampfer S, Streffer C
Institut für Medizinische Strahlenbiologie, Universitätsklinikum Essen, Federal Republic of Germany.
Teratology. 1988 Jun;37(6):599-607. doi: 10.1002/tera.1420370609.
Female mice (strain: "Heiligenberger Stamm") were irradiated with neutrons (7 MeV) or X-rays when embryos were at the early zygote stage; uterine contents were examined on gestation day 19 for prenatal mortality and malformed fetuses. For both radiation qualities, the dose-dependent survival curve fitted well to a simple exponential equation; the neutron relative biological efficiency (RBE) value was 2.3. The major fraction of deaths induced by exposure to neutrons or X-rays occurred before implantation. Aside from dead embryos, malformed fetuses were observed 19 days p.c. (postconception). The number of malformed fetuses increased with a linear-quadratic function of neutron or X-ray dose. Malformations were mainly gastroschisis, although omphaloceles and anencephalies were also observed. The neutron RBE value for the induction of malformations varied from 2.0 to 2.8 in the dose range tested. Except after 75-cGy neutrons, no significant increase in the proportion of stunted or skeletally malformed fetuses was noted. Our results indicated that the reaction of preimplantation embryos to irradiation could be more complex than the simple "all-or-none" response considered so far.
雌性小鼠（品系：“Heiligenberger Stamm”）在胚胎处于早期合子期时接受中子（7兆电子伏特）或X射线照射；在妊娠第19天检查子宫内容物，以确定产前死亡率和畸形胎儿情况。对于这两种辐射类型，剂量依赖性存活曲线都很好地拟合了一个简单的指数方程；中子的相对生物效能（RBE）值为2.3。中子或X射线照射引起的死亡主要发生在着床前。除了死亡胚胎外，在妊娠19天（受孕后）观察到了畸形胎儿。畸形胎儿的数量随中子或X射线剂量呈线性二次函数增加。畸形主要为腹裂，不过也观察到了脐膨出和无脑儿。在所测试的剂量范围内，中子诱导畸形的RBE值在2.0至2.8之间变化。除了75厘戈瑞中子照射后，未观察到发育迟缓或骨骼畸形胎儿比例有显著增加。我们的结果表明，着床前胚胎对辐射的反应可能比迄今所认为的简单“全或无”反应更为复杂。
