Perinatal exposure to bisphenol-A alters peripubertal mammary gland development in mice

Developmental exposure to estrogenic chemicals induces morphological, functional, and behavioral anomalies associ-ated with reproduction. Humans are exposed to bisphenol-A (BPA), an estrogenic compound that leaches from dental ma-terials and plastic food and beverage containers. The aim of the present study was to determine the effects of perinatal exposure to low, environmentally relevant doses of BPA [25 and 250 ng BPA/kg body weight (bw)d] on the peripubertal development of themammary gland. BPA exposure enhanced the mammary glands ’ sensitivity to estradiol in ovariecto-mized CD-1 mice. In their intact 30-d-old littermates, the area and numbers of terminal end buds relative to the gland ductal area increased whereas their apoptotic activity decreased. There was a positive correlation between ductal length and the age at first proestrus; that was reduced as the BPA dos