Pampfer S, Müller W U, Streffer C
Institut für Medizinische Strahlenbiologie, Universitätsklinikum Essen, West Germany.
Radiat Res. 1992 Jan;129(1):88-95.
Mouse zygotes were irradiated with fast neutrons (0.06 to 1.00 Gy) 1 h after conception and examined at various intervals (24 to 100 h after conception) for embryonic development and micronucleus formation. The frequency of micronuclei per cell increased linearly with dose in 2-cell embryos observed at 24 h after conception and in 4-cell and 8-cell embryos at 48 h after conception. Compared with X rays, the relative biological effectiveness of neutrons for the induction of micronuclei per embryo was 2.5 at 24 h after conception and 3.5 at 48 h after conception. Neutron-induced micronucleus formation was accompanied by morphological growth delay and a significant decrease in the number of cells in the embryos. An inverse relationship was found between the number of cells in embryos and the number of micronuclei when observed at 48 h after conception following irradiation with 0.12 to 1.00 Gy and at 78 h after conception following exposure to 0.50 Gy. The effect of neutron irradiation on embryonic development was likely to be mediated by cell death, as suggested by a significantly increased dead cell index in blastocysts following irradiation of zygotes.
在受孕后1小时，用快中子（0.06至1.00 Gy）照射小鼠受精卵，并在不同时间间隔（受孕后24至100小时）检查胚胎发育和微核形成情况。在受孕后24小时观察到的2细胞胚胎以及受孕后48小时观察到的4细胞和8细胞胚胎中，每细胞的微核频率随剂量呈线性增加。与X射线相比，受孕后24小时中子诱导每个胚胎微核的相对生物效应为2.5，受孕后48小时为3.5。中子诱导的微核形成伴随着形态学上的生长延迟以及胚胎中细胞数量的显著减少。当在受孕后48小时观察0.12至1.00 Gy照射后的胚胎以及受孕后78小时观察0.50 Gy照射后的胚胎时，发现胚胎中的细胞数量与微核数量呈负相关。如受精卵照射后囊胚中死细胞指数显著增加所表明的，中子照射对胚胎发育的影响可能是由细胞死亡介导的。
