THE EFFECTS OF POLYBROMINATED BIPHENYLS AND PERCHLORINATED TERPHENYLSON IN-VITRO FERTILIZATION IN THE MOUSE

Polybrominated biphenyls (PBBs) and perchlorinated terphenyls (PCTs) a re industrial chemicals that are long-lasting environmental contaminan ts. Although in vivo effects of PBBs on reproduction are documented, n o information is available on the effects of these chemicals on sperm- egg interactions or fertilization. The present study was undertaken to determine the toxic potential of PBBs and PCTs on in vitro fertilizat ion (IVF) in the mouse. 2-Bromobiphenyl, 4-bromobiphenyl, o-terphenyl, m-terphenyl, and p-terphenyl were added to the IVF medium at various concentrations. Oocytes collected from superovulated B6D2F1 mice were maintained in a medium containing the chemicals. Capacitated sperm wer e then added and the dishes cultured in a humidified atmosphere at 37- degrees-C in 5% CO2 + 95% air. Oocytes were assessed for fertilization 20-24 h after insemination. polybrominated biphenyls and PCTs reduced the IVF rate at the higher dosages. Furthermore, an increased inciden ce of abnormal two-cell embryos and degenerative oocytes was observed at the 1 and 10 mug/ml concentrations of PBBs and PCTs. These results indicate that PBBs and PCTs adversely effect IVF and increase the inci dence of abnormal embryos and oocyte degeneration in the mouse.