Influence of maternal zinc deficiency and irradiation on in utero development in mice

It is well established that In mammals transitory Zn deficiency during embryogenesis can have a negative influence on fetal development. Similar in 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 dosed once with 0, .05, .1 or .25 Gy of γ-radiation the day after mating (GD0), or with 0 or .5 Gy on GD8. Mice irradiated on GD0 were either fed a low Zn diet (LznD, 0.4, ug Zn/g), for 48 h prior to mating through GD0 or GD0 and GD5and then switched to a control diet (50 ug Zn/R) through GD18. or they were fed the control throughout. The dams irradiated on GD8 were either fed the LZnD from GD0 through GD10 and then switched to the control, or they were fed the control throughout. Zn deprivation did not influente any of the maternal or embryonic/fetal parameters measured in the cohorts fed the LZnD through GD0. In contrast, mice led the LZnD through GD5 or GD10 had significantly lower mean maternal body weights, fewer live fetuses/litter, and a higher incidence of resorptions compared to controls. No influence of irradiation on GD0 or GD8 was observed for any of the parameters measured. These results show that despite a functional Zn deficiency in one cohort, the sensitivity of the conceptus to low-dose irradiation was not increased.