Dominant lethal test in female mice treated with methyl mercury chloride.

Female BALB/c mice were treated with a single intraperitoneal injection of 0, 2.5, 5.0 or 7.5 mg methyl mercury chloride per kg body weight and subjected to the dominant lethal assay at 6 different time intervals between exposure and mating. Cyclophosphamide (210 mg/kg body weight) was used as a positive control. The main observation appeared to be a statistically highly significant increase in especially pre- and early post-implantation foetal losses. This was most evident when all data (the 6 consecutive weeks of mating) were pooled.