Hanna L A, Peters J M, Wiley L M, Zidenberg-Cherr S, Keen C L
Department of Nutrition, University of California, Davis 95616, USA.
Teratog Carcinog Mutagen. 1997;17(3):127-37.
It is well established that in mammals transitory zinc (Zn) deficiency during embryogenesis can have a negative influence on fetal development. Similar to Zn deficiency, maternal exposure to low levels of ionizing radiation during the first day of pregnancy has been shown to negatively affect preimplantation embryo development, and higher doses of maternal irradiation during late stages of embryogenesis can result in malformations. Here we report the effect of transitory maternal Zn deprivation combined with low dose irradiation during embryogenesis on fetal outcome. Pregnant mice were acutely dosed with 0.00, 0.05, 0.10, or 0.25 Gy of gamma-radiation the day after mating (GD0), or with 0.00 or 0.50 Gy on GD8. Mice irradiated on GD0 were either fed a low Zn diet (0.4 microgram Zn/g) for 48 h prior to mating through GD0 or GD5 and then switched to a control diet (50 micrograms Zn/g) through GD18, or they were fed the control diet throughout gestation. Dams irradiated on GD8 were either fed the low Zn diet from GD0 through GD10 and then switched to the control diet, or they were fed the control diet throughout gestation. Zn deprivation did not influence any of the maternal or embryonic/fetal parameters measured in the cohorts fed the low Zn diet through GD0. In contrast, groups fed the low Zn diet through GD5 or GD10 had lower mean maternal body weights, fewer live fetuses/litter, and a higher incidence of resorptions than controls. Fetuses from dams fed the low Zn diet through GD10 were smaller and shorter, and had a higher frequency of malformations than controls. Irradiation on GD8 under adequate Zn conditions had no effect on any parameter, but GD8 irradiation during maternal Zn deficiency had an additive effect on the frequency of fetal malformations.
众所周知，在哺乳动物中，胚胎发育期间短暂的锌（Zn）缺乏会对胎儿发育产生负面影响。与锌缺乏类似，孕期第一天母体暴露于低水平电离辐射已被证明会对植入前胚胎发育产生负面影响，而在胚胎发育后期更高剂量的母体辐射会导致畸形。在此，我们报告胚胎发育期间母体短暂锌缺乏与低剂量辐射相结合对胎儿结局的影响。怀孕小鼠在交配后第二天（妊娠第0天，GD0）急性给予0.00、0.05、0.10或0.25 Gy的γ射线，或在GD8给予0.00或0.50 Gy。在GD0接受辐射的小鼠，在交配前至GD0或GD5期间喂以低锌饮食（0.4微克锌/克）48小时，然后在GD18之前改为对照饮食（50微克锌/克），或者在整个妊娠期喂以对照饮食。在GD8接受辐射的母鼠，要么从GD0至GD10喂以低锌饮食，然后改为对照饮食，要么在整个妊娠期喂以对照饮食。在GD0期间喂以低锌饮食的组中，锌缺乏对所测量的任何母体或胚胎/胎儿参数均无影响。相比之下，在GD5或GD10期间喂以低锌饮食的组，其母体平均体重较低，每窝活胎较少，吸收发生率高于对照组。在GD10期间喂以低锌饮食的母鼠所产胎儿更小、更短，畸形发生率高于对照组。在充足锌条件下，GD8辐射对任何参数均无影响，但母体锌缺乏期间的GD8辐射对胎儿畸形频率有累加效应。
