Maternal and Fetal Exposure to Bisphenol A Is Associated with Alterations of Thyroid Function in Pregnant Ewes and Their Newborn Lambs

Catherine Viguié (1) , Séverine Collet (2) , Véronique V. Gayrard-Troy (1) , Nicole Picard-Hagen (3) , Sylvie Puel (1) , Béatrice Roques (1) , Pierre-Louis Toutain (1) , Marlène Z. Lacroix (1)

1 UTA - Toxicologie Alimentaire
2 INRA - Institut National de la Recherche Agronomique
3 ToxAlim-EXPER - Exposition, Perturbation Endocrino-métabolique et Reproduction

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.

Domaines: Sciences du Vivant [q-bio]

Catherine Viguié, Séverine Collet, Véronique V. Gayrard-Troy, Nicole Picard-Hagen, Sylvie Puel, et al.. Maternal and Fetal Exposure to Bisphenol A Is Associated with Alterations of Thyroid Function in Pregnant Ewes and Their Newborn Lambs. Endocrinology, 2013, 154 (1), pp.521-528. ⟨10.1210/en.2012-1401⟩. ⟨hal-01228311⟩