Nickel toxicity in early embryogenesis in mice.

The development of mouse embryos was studied after intraperitoneal injection of nickel chloride in the preimplantation period. A single intraperitoneal injection of NiCl2 . 6H2O in 0.154 M NaCl corresponding to 20 mg/kg body wt was given to groups of female mice on days 1, 2, 3, 4, 5 or 6 of gestation. Control groups were injected with 0.154 M NaCl. Caesarean section was performed on day 19 of gestation and the following parameters were recorded: implantation frequency, frequency of early and late resorptions, frequency of liver normal fetuses, abnormal fetuses and stillborns, and the weight of each fetus. The implantation frequency of females treated with nickel chloride on the first day of gestation was significantly lower than that of the controls. The size of the litters in the control groups was larger than that of the nickel treated dams, significant difference being observed on days 1, 3 and 5. NiCl2 . 6H2O injection also resulted in diminished body weights of fetuses on day 19 of gestation. The groups of nickel treated mice had a larger frequency of both early and late resorptions and the frequency of stillborn and abnormal fetuses exceeded that of the control groups. This study shows that, by the procedure used, nickel chloride may influence mouse embryos during the passage through the oviduct with subsequent effect on the development after implantation.U