FERTILITY IN MICE AFTER PRENATAL EXPOSURE TO BENZO[A]PYRENE AND INORGANIC LEAD

Experimental evidence suggests that inorganic lead and benzo[a]pyrene (BaP) suppress the development of primordial oocytes during fetal life . We examined the single and combined effects of prenatal exposure to BaP and moderate doses of lead. The fertility and ovarian morphology o f F-1 female NMRI mice in four treatment groups (nine mice per group) were investigated: control; lead (F-0 given 1 g PbCl2/L in drinking wa ter until mating); BaP (10 mg/kg body weight daily by oral intubation on days 7-16 of F-0 pregnancy); and combined lead and BaP. F-1 groups exposed prenatally to BaP either alone or in combination with inorgani c lead showed markedly reduced fertility with few ovarian follicles co mpared to controls, whereas the group exposed to lead only had measure s comparable to the controls. Mice exposed to both lead and BaP had a significantly longer gestation period (days to litter) compared to mic e exposed only to BaP, lead or controls. There is a nonsignificant: in dication that the compounds together further reduce number of offsprin g, number of litters, and litter size. These results suggest that lead and BaP have synergistic effects on impairment of fertility. The poss ibility of synergism may be of human relevance as inorganic lead and B ap are ubiquitous environmental pollutants.