EFFECTS OF 3,3',4,4'-TETRACHLOROBIPHENYL ON FETAL GERM-CELLS IN 2 MOUSE STRAINS AFTER REPEATED TREATMENT OF THE DAMS DURING AND AFTER PREGNANCY

Female mice from the C57/Bl- and CBA/S-strain, respectively, were admi nistered 3,3'4,4'-tetrachlorobiphenyl once a week for two weeks prior to mating, during mating, gestation and lactation, altogether at seven weekly occasions. The orally administered amounts were 9 or 15 mg/kg b.wt. per occasion. Male and female offspring (Fl), exposed in utero w ere collected for histological analysis of the testes and ovaries. Oth er C57/Bl-females (Fl) were tested for their reproductive capacity. In the C57/Bl-males tetrachlorobiphenyl only had a temporary effect on g erm cell numbers, and spermatogenesis was normal again at 56 days afte r birth. In the ovaries 28 days after birth, an increased number of oo cytes and follicles were observed, the effect being more pronounced in the C57/Bl-strain. The reproductive capacity expressed as mean litter size seemed not to be affected by the histologically observed changes . Concerning the number of litters per female there were indications o f an enhanced productivity in tetrachlorobiphenyl-exposed Fl-females. Malformations of any kind were not observed.