Embryocidal and teratogenic effects of methylmercury in mice

Abstract

Embryocidal and teratogenic effects of methylmercury hydroxide (MeHgOH) were determined in three strains of mice, C57BL 6J , CD, and 129 SvSl . In single dose experiments, a dose of 0, 2, 4, 8, or 12 mg/kg of MeHgOH was administered by various routes to all three strains of pregnant mice on Day 10 of gestation. For multiple dose experiments, a daily dose of 0, 2, 4, 6, 8, or 10 mg/kg was injected sc to 129 SvSl mice from Days 7 to 12 of gestation. The fetotoxic effects were examined on Day 18 of gestation. Embryocidal and teratogenic effects were noted in all three strains of mice. Cleft palate was the most frequently observed teratogenic malformation. Other malformations, such as anophthalmia, micrognathia, exencephaly, missing limbs, and facial deformity, were seen infrequently. Multiple dose administration of MeHg to pregnant dams caused a higher incidence of MeHg teratogenesis with a lower incidence of maternal toxicity in comparison to single dose administration. Present findings indicate that all three species of mice investigated are susceptible to the teratogenic effects of MeHg.