The role of sulfation in thyroid hormone metabolism

Abstract

The type 1 iodothyronine deiodinase (1D-I) in liver and kidney converts the prohormone thyroxine ('1"4) by outer ring deiodination (ORD) to bioactive 3,3',5-triiodothyronine (T3) or by inner ring deiodination (IRD) to inactive 3,3',5-"triiodothronine (rT3), while it also catalyzes the IRD of T3 and the ORD of rT 3, with the latter as the preferred substrate. Sulfation of the phenolic hydroxyl group blocks the ORD of T 4, while it strongly stimulates the IRD of both T 4 and T3, indicating that sulfation is an important step in the irreversible inactivation of thyroid hormone. This review summarizes recent studies concerning this interaction between sulfation and deiodination of iodothyronines, the characterization of iodothyronine sulfotransferase activities, the measurement of iodothyronine sulfates in humans and animals, and the possible physiological importance of iodothyronine sulfation.

Bioconcentration and metabolism of decabromodiphenyl ether (BDE-209) result in thyroid endocrine disruption in zebrafish larvae

“…In addition, it has been suggested that uridinediphosphate glucoronosyltransferases (UGT) and sulfotransferases (SULTs) play important roles in TH homeostasis, via the major pathway for T4 conjugation (Visser, 1994;Hood and Klaassen, 2000). Several previous studies in rodents have shown that decreased T4 levels are accompanied by increased UGT activities or gene transcription (Zhou et al, 2001;Hallgren and Darnerud, 2002;Szabo et al, 2009).…”

The effect of acute exercise session on thyroid hormone economy in rats

“…D1 and D2 catalyze the 5 0 -deiodination of T 4 and are considered activating enzymes due to subsequent T 3 production. The role of D3 is to inactivate T 4 and T 3 through their 5-deiodination (Visser 1994, Bianco et al 2002, Bianco & Kim 2006. Thus, deiodinases can acutely regulate serum T 4 and T 3 levels and also their tissue availability through their activation or inactivation.…”

High Accuracy in Silico Sulfotransferase Models

“…The in vivo activities of these compounds are regulated by sulfation, which often profoundly alters their target affinities (5)(6)(7)(8). SULTs perform at least two essential metabolic functions: a homeostatic function, in which, for example, they regulate the receptor binding activities of peptide and steroid hormones (6,7), and a defensive function (9,10), in which they sulfonate the myriad compounds that pass through the liver and would otherwise adventitiously bind receptors and regulate cellular signaling systems.…”