The combined treatment of preimplantation mouse embryos in vitro with cadmium (CdSO4, CdF2) and X-rays

The influence of cadmium (up to 10^?4 M), fluoride (up to 10^?4 M), and X-rays (up to 18.8 Gy) on different variables of preimplantation mouse embryos in vitro has been examined. The agents were applied either singly or in combination (0.94 Gy X-rays +3×10^?7 M CdSO₄ or CdF₂; 0.94 Gy X-rays +3×10^?6 M CdSO₄ or CdF₂). The following variables were determined:

1. the microscopic visible development until 144 h post conceptionem (=144 h p.c.),
2. the average cell numbers (48 h p.c., 56 h p.c., 72 h p.c., 96 h p.c., 120 h p.c., 144 h p.c.),
3. the number of micronuclei (72 h p.c.),
4. the distribution of cell nuclei within the cell cycle (72 h p.c.).

Nearly all results of the combination experiments correspond to the sum of the single effects. Only two values (out of about 40) significantly exceed the value obtained after addition of the single effects; both values lie within the envelope of additivity.