摘要：ackground:Bisphenol A (BPA) risk assessment is currently hindered by the rejection of reported higher-than-expected plasma BPA concentrations in humans after oral ingestion. These are deemed incompatible with the almost complete hepatic first-pass metabolism of BPA into its inactive glucurono-conjugated form, BPA glucuronide (BPAG).oBjectives:Using dogs as a valid model, we compared plasma concentrations of BPA over a 24-hr period after intravenous, oro gastric, and sub lingual administration in order to establish the absolute bioavailability of BPA administered sub lingually and to compare it with oral bioavailability.Methods:Six dogs were sublingually administered BPA at 0.05 mg/kg and 5 mg/kg. We compared the time course of plasma BPA concentrations with that obtained in the same dogs after intravenous administration of the same BPA doses and after a 20-mg/kg BPA dose administrated by oro gastric gavage.results:The data indicated that the systemic bioavailability of BPA deposited sublingually was high (70–90%) and that BPA transmucosal absorption from the oral cavity led to much higher BPA internal exposure than obtained for BPA absorption from the gastro intestinal tract. The concen-tra tion ratio of BPAG to BPA in plasma was approximately 100-fold lower following sub lingual administration than after oro gastric dosing, distinguishing the two pathways of absorption. conclusio ns:Our findings demonstrate that BPA can be efficiently and very rapidly absorbed through the oral mucosa after sub lingual exposure. This efficient systemic entry route of BPA may lead to far higher BPA internal exposures than known for BPA absorption from the gastro intestinal tract
关键词：bioavailability; bisphenol A; endocrine disruptor; pharmacokinetic analysis; sub ;lingual ;exposure
