[Disorders in thyroid hormone metabolism].
The levels of the serum thyroid hormone (free T4 and free T3) are determined not only by thyroid hormone synthesis/secretion but also by their metabolism. Thyroid hormone metabolism is mediated by three selenoproteins, selenodeiodinase type 1, 2, and 3 (D1, D2, and D3), the expression and function of which are tightly regulated in a tissue-specific manner. Among them, D2 increases and D3 decreases the intracellular thyroid hormone levels, whereas D1 seems to play a role as a housekeeping/scavenger enzyme in general thyroid hormone metabolism. Although no mutation in either of the deiodinase enzyme genes has been reported, some related genes (SECISBP2, DEHAL1, and MCT8) can cause thyroid hormone-related inherited disorders. In addition, a variety of hormones, cytokines, and drugs can influence thyroid function through altered thyroid hormone metabolism.
Iwasaki
Yasumasa
Y
Department of Endocrinology, Metabolism, and Nephrology, Health Care Center, Kochi University, Kochi 780-8520, Japan. iwasaki@kochi-u.ac.jp
D006801:Humans; D006867:Hydrolases / Q000502:physiology; D007249:Inflammation / Q000150:complications; D007453:Iodide Peroxidase / Q000502:physiology; D008565:Membrane Proteins / Q000502:physiology; D027501:Monocarboxylic Acid Transporters / Q000235:genetics / Q000502:physiology; D009154:Mutation; D009369:Neoplasms; D016601:RNA-Binding Proteins / Q000235:genetics / Q000502:physiology; D012643:Selenium / Q000172:deficiency; D051140:Selenoproteins / Q000502:physiology; D027981:Symporters; D013959:Thyroid Diseases / Q000209:etiology / Q000378:metabolism; D013963:Thyroid Hormones / Q000097:blood / Q000378:metabolism*
D008565:Membrane Proteins; D027501:Monocarboxylic Acid Transporters; D016601:RNA-Binding Proteins; C121530:SECISBP2 protein, human; C090735:SLC16A2 protein, human; D051140:Selenoproteins; D027981:Symporters; D013963:Thyroid Hormones; D007453:Iodide Peroxidase; D006867:Hydrolases; C497447:IYD protein, human; D012643:Selenium