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ABSTRACT: Background
Bisphenol A (BPA) is a widely produced endocrine-disrupting chemical. Diet is a primary route of exposure, but internal exposure (serum concentrations) in animals and humans has been measured only after single oral bolus administration.Objective
We compared serum concentrations of BPA over a 24-hr period after oral bolus administration or ad libitum feeding in mice and assessed for buildup with dietary exposure.Methods
Adult female mice were administered [dimethyl-d6]-BPA (BPA-d6) as a single oral bolus (20 mg/kg body weight) or fed a diet containing 100 mg BPA-d6/kg feed weight ad libitum for 1 week. Serum concentrations were analyzed using isotope dilution liquid chromatography coupled with electrospray tandem mass spectrometry and compared between exposure groups over the first 23 hr and after 7 days of dietary exposure.Results
Maximum concentration (Cmax) for BPA-d6 during the first 24 hr was reached at 1 hr and 6 hr for oral bolus and diet groups, respectively. Relative BPA-d6 bioavailability (unconjugated BPA-d6) was higher in diet-exposed mice than in the bolus group despite a relative lower absorption, a phenomenon consistent with an inhibitory effect of food on first-pass hepatic metabolism. In mice with ongoing dietary exposure, unconjugated BPA-d6 was higher on day 7 than on day 1.Conclusions
This is the first report of serum BPA concentrations in an animal model exposed to this chemical via the diet. Although bolus administration of BPA-d6 led to peak concentrations within 1 hr, Cmax for diet-exposed mice was delayed for several hours. However, bolus administration underestimates bioavailable serum BPA concentrations in animals-and presumably humans-than would result from dietary exposure. Exposure via diet is a more natural continuous exposure route than oral bolus exposure and is thus a better predictor of BPA concentrations in chronically exposed animals and humans.
SUBMITTER: Sieli PT
PROVIDER: S-EPMC3230401 | biostudies-literature | 2011 Sep
REPOSITORIES: biostudies-literature
Sieli Paizlee T PT Jašarevic Eldin E Warzak Denise A DA Mao Jiude J Ellersieck Mark R MR Liao Chunyang C Kannan Kurunthachalam K Collet Séverine H SH Toutain Pierre-Louis PL Vom Saal Frederick S FS Rosenfeld Cheryl S CS
Environmental health perspectives 20110606 9
<h4>Background</h4>Bisphenol A (BPA) is a widely produced endocrine-disrupting chemical. Diet is a primary route of exposure, but internal exposure (serum concentrations) in animals and humans has been measured only after single oral bolus administration.<h4>Objective</h4>We compared serum concentrations of BPA over a 24-hr period after oral bolus administration or ad libitum feeding in mice and assessed for buildup with dietary exposure.<h4>Methods</h4>Adult female mice were administered [dimet ...[more]