Uterotrophic activity of bisphenol A in the immature rat

Bisphenol A (BPA) is active in immature AP rat uterotrophic assays when eva luated using either the oral or the subcutaneous (sc) injection routes of e xposure (three daily administrations of 400-800 mg/kg BPA). Premature vagin al opening was seen for 8 of 14 animals exposed to 600 and 800 mg/kg BPA by sc injection. Vaginal opening was not produced by BPA in the gavage studie s. These results are consistent with those of Dodds and Lawson [Nature 137: 96 (1936)] who found that BPA induces persistent vaginal cornification in o variectomized rats exposed to three twice-daily injections of 85 mg/kg BPA (total daily dose 170 mg/kg), but they conflict with the reported inactivit y of BPA in the immature mouse uterotrophic assay. The uterotrophic activit y of diethylstilbestrol in the rat is also established (0.04 mg/kg/day for three days).