Distribution of 14C-bisphenol A in pregnant and newborn mice

ObjectivesThe purpose of the present investigation was to trace the fate of bisphenol A injected into pregnant mice, focusing on its potential accumulation in the fetus and the brain, critical targets of hormonal chemicals, using whole-body autoradiography.MethodsPregnant mice were injected intraperitoneally with 0.46 MBq of 14C-BPA and then killed at 1 h or 1, 3, or 5 days after injection. Sections for autoradiography were prepared in a cryomicrotome and the exposed imaging plate was processed using a fluorescent/radioisotope image analyzer.ResultsIntraperitoneally injected 14C-BPA was distributed throughout the body, including the fetus and the brain, within 1 h. Radioactivity faded gradually from the whole body by the fifth day, and no accumulation in any specific organ was found. However, although 14C was detected in the fetuses immediately after injection, the transfer of BPA from mother to newborn was not observed.SignificanceThe routes of rapid BPA discharge were confirmed, and BPA neither accumulated in the body nor was it transferred to newborn mice. No evidence was observed to suggest the existence of a blood–placenta or blood–brain barrier for BPA. This information should be taken into consideration when assessing the risks of using dental materials that contain BPA.