Comparative endocrine disruptive effects of contaminants in ringed seals ( Phoca hispida) from Svalbard and the Baltic Sea

• Published in: Comparative biochemistry and physiology. Toxicology & pharmacology 2010-09, Vol.152 (3), p.306-312
• Main Authors: Routti, Heli, Arukwe, Augustine, Jenssen, Bjørn Munro, Letcher, Robert J., Nyman, Madeleine, Bäckman, Christina, Gabrielsen, Geir Wing
• Format: Article
• Language: English
• Subjects: Animals; Baltic Sea; Biomarkers - blood; Biomarkers - metabolism; Calcitriol; Deiodinase; Endocrine Disruptors - metabolism; Female; Interleukin-1beta - blood; Interleukin-1beta - genetics; Interleukin-1beta - metabolism; Iodide Peroxidase - blood; Liver - enzymology; Liver - metabolism; Male; Marine; Phoca - blood; Phoca - metabolism; Phoca hispida; Receptors, Retinoic Acid - blood; Receptors, Retinoic Acid - genetics; Receptors, Retinoic Acid - metabolism; Receptors, Somatotropin - blood; Receptors, Somatotropin - genetics; Retinoic acid receptor; Retinoic Acid Receptor alpha; RNA, Messenger - metabolism; Svalbard; Thyroid hormone; Thyroid hormone receptor; Thyroid Hormone Receptors beta - blood; Thyroid Hormone Receptors beta - genetics; Triiodothyronine - blood; Vitamin A; Vitamin A - blood; Vitamin A - genetics; Vitamin A - metabolism; Water Pollutants, Chemical - metabolism
• ISSN: 1532-0456; 1878-1659
• DOI: 10.1016/j.cbpc.2010.05.006

We investigated variables related to thyroid, vitamin A and calcitriol homeostasis, immune function and tumour development in ringed seals ( Phoca hispida) from the polluted Baltic Sea and a less polluted reference location at Svalbard, Norway. We also examined the relationships between the biological variables and the concentrations of persistent organic pollutants (POPs) and their hydroxylated (OH) metabolites. Our data show higher plasma concentrations of free triiodothyronine (T3), and ratios of free and total T3 in Baltic seals as compared to Svalbard seals. Baltic seals had also higher hepatic mRNA expressions of deiodinase-I, thyroid hormone receptor β, retinoic acid receptor α, growth hormone receptor and interleukin-1β compared to Svalbard seals. Levels of plasma retinol were lower in the Baltic seals as compared to Svalbard seals. No geographical difference was observed for other thyroid hormone levels and hepatic retinoid levels. Ratios of free and total T3 were positively correlated to OH-POPs in plasma. The results of the present study suggest that endocrine homeostasis may be affected by contaminant and metabolite exposure in the Baltic ringed seals with respect to circulating hormones and retinol and hepatic mRNA expressions. In addition, OH-POPs may putatively produce the disruption of thyroid hormone transport in plasma.