title: Maternal and fetal exposure to bisphenol a is associated with alterations of thyroid function in pregnant ewes and their newborn lambs.
abstract: The putative thyroid-disrupting properties of bisphenol A (BPA) highlight the need for an evaluation of fetal exposure and its consequence on the mother/newborn thyroid functions in models relevant to human. The goals of this study were to characterize in sheep a relevant model for human pregnancy and thyroid physiology, the internal exposures of the fetuses and their mothers to BPA and its main metabolite BPA-glucuronide (Gluc), and to determine to what extent it might be associated with thyroid disruption. Ewes were treated with BPA [5 mg/(kg · d) sc] or vehicle from d 28 until the end of pregnancy. Unconjugated BPA did not appear to accumulate in pregnant ewes, and its concentration was similar in the newborns and their mothers (0.13 ± 0.02 and 0.18 ± 0.03 nmol/ml in cord and maternal blood, respectively). In amniotic fluid and cord blood, BPA-Gluc concentrations were about 1300-fold higher than those of BPA. Total T(4) concentrations were decreased in BPA-treated pregnant ewes and in the cord and the jugular blood of their newborns (30% decrease). A similar difference was observed for free T(4) plasma concentrations in the jugular blood of the newborns. Our results show in a long-gestation species with a similar regulatory scheme of thyroid function as humans that BPA in utero exposure can be associated with hypothyroidism in the newborns. If such an effect were to be confirmed for a more relevant exposure scheme to BPA, this would constitute a major issue for BPA risk assessment.
authors.affiliation: Institut National de la Recherche Agronomique/Institut National Polytechnique/Université Paul Sabatire, Ecole Nationale Vétérinaire de Toulouse, Laboratoire de Physiologie, 23 chemin des Capelles, BP 87614, F-31076 Toulouse cedex 3, France. c.viguie@envt.fr
authors.forename: Catherine
authors.initials: C
authors.lastname: Viguié
authors.forename: Séverine H
authors.initials: SH
authors.lastname: Collet
authors.forename: Véronique
authors.initials: V
authors.lastname: Gayrard
authors.forename: Nicole
authors.initials: N
authors.lastname: Picard-Hagen
authors.forename: Sylvie
authors.initials: S
authors.lastname: Puel
authors.forename: Béatrice B
authors.initials: BB
authors.lastname: Roques
authors.forename: Pierre-Louis
authors.initials: PL
authors.lastname: Toutain
authors.forename: Marlène Z
authors.initials: MZ
authors.lastname: Lacroix
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001559:Benzhydryl Compounds / Q000633:toxicity*; D005260:Female; D018811:Maternal Exposure / Q000009:adverse effects*; D010636:Phenols / Q000633:toxicity*; D011247:Pregnancy; D012756:Sheep; D013961:Thyroid Gland / Q000187:drug effects* / Q000378:metabolism; D013974:Thyroxine / Q000097:blood; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D010636:Phenols; D013974:Thyroxine; C006780:bisphenol A; D000098826:Bisphenol A Compounds