Effects of pentachlorophenol and hydroxylated polychlorinated biphenyls on thyroid hormone conjugation in a rat and a human hepatoma cell line

摘要: Abstract It was previously demonstrated in our laboratory that hydroxylated metabolites of polychlorinated biphenyls (PCB-OHs) inhibit the sulfation iodothyronines rat liver cytosol. In this study, inhibition 3,3′-diiodothyronine (T2) by pentachlorophenol (PCP) and PCB-OHs investigated hepatoma cell lines relation to cellular uptake these compounds, providing a more appropriate model vivo situation. The human HepG2 line shown conjugate T2 almost exclusively sulfation, glucuronidation being negligible. FaO line, on other hand, produced 37% sulfate 63% glucuronide. PCP inhibited both lines, although it 103 times less potent cells than Remarkably, 10 μ m same extent. Micromolar concentrations 4-hydroxy-3,3′,4′,5-tetrachlorobiphenyl or 4-hydroxy-2′,3,3′,4′,5-pentachlorobiphenyl hardly affected conjugation cells, but reduced formation cells. Inhibition stronger using medium without foetal calf serum (FCS) with 5% FCS. This due lower inhibitor presence serum, as radiolabelled PCP. conclusion, study confirms observed cytosol line. Thus, seems reasonable assume iodothyronine is also PCB vivo.