Abstract
4-Nonylphenol (4-NP), a compound of concern as an estrogenic xenobiotic, was assessed for its ability to modify prostate carcinogenesis in male offspring exposed prenatally and neonatally. 4-NP was administered to F344 female rats by gavage at a dose of 0, 0.1, 10 or 100 mg/kg during pregnancy and the lactation period. A slight suppression of maternal body weight gain and prolongation of the gestation period were observed at a 4-NP dose of 100 mg/kg. At this dose, a slight decrease in the mean number of newborn (live + stillborn), and a slight increase in the mean number of stillborn with an increase in the male ratio were observed, suggesting a lethality, presumably in females, although all data were not statistically significant. Male offspring received 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP) by gavage at a dose of 100 mg/kg once a week from 5 weeks of age for 19 weeks and all surviving animals were sacrificed at the age of 65 weeks. There was no variation in growth rates among the treated groups. Histopathological examination did not reveal any differences in tumor morphology or incidence in the prostate. We concluded that gestational and lactational exposure to 4-NP does not modify susceptibility of male offspring to a food-derived prostate carcinogen, PhIP at a later stage.
