Serum bisphenol A pharmacokinetics and prostate neoplastic responses following oral and subcutaneous exposures in neonatal Sprague–Dawley rats

The present study examines BPA pharmacokinetics in neonatal rats following s.c. injection or oral delivery of 10 μg BPA/kg BW and compares susceptibility to estrogen-induced prostate intraepithelial neoplasia (PIN) following either exposure route. Serum BPA in PND3 rats was measured using HPLC–MS–MS. Free and total BPA at Cmax were 1.77 and 2.0 ng/ml, respectively following injection and 0.26 and 1.02 ng/ml, respectively following oral exposure. The AUC0–2 for free and total BPA was 4.1-fold and 1.8-fold greater, respectively, in s.c. vs. oral delivery. While exposure route affected BPA metabolism, internal dosimetry following s.c. injection of 10 μg BPA/kg BW is similar to BPA levels observed in humans. Prostates from aged rats given s.c. or oral BPA neonatally and T + E implants as adults exhibited nearly identical, heightened susceptibility to PIN incidence and score as compared to neonatal oil-controls. These findings on prostate health are directly relevant to humans at current BPA exposure levels.