Polybrominated diphenyl ether (PBDE)-induced alterations in thyroid hormone and vitamin A metabolism

Polybrominated Diphenyl Ethers (PBDEs) are persistent environmental contaminants that have been demonstrated to bioaccumulate in human and environmental samples. The predominant congeners documented to exhibit the greatest bioaccumulation are primary found in the penta-BDE commercial mixture. Limited data exists regarding the effects of PBDEs in humans. In animal models, exposure to penta-BDE commercial mixtures and/or purified PBDE congeners has been demonstrated to disrupt nervous system development and endocrine signaling, including thyroid hormones and vitamin A. As thyroid hormones and vitamin A are key regulators of normal pre- and postnatal development in mammals, more research is necessary to characterize the disruption potential of penta-BDE mixtures and purified PBDE congeners of these two endocrine signalling pathways. This dissertation focuses on extending our understanding of PBDE's disruptions of thyroid hormone and vitamin A metabolism in the Sprague-Dawley rat. The inclusion of animals marginal or sufficient in their vitamin A status provides critical information regarding nutrient-toxicant interactions associated with PBDEs. Also prenatal and postnatal developmental assessments were conducted.