Iodothyronine
Synonym(s)
DefinitionThis section has been translated automatically.
General term for thyroid hormones that have an iodine-containing amine structure.
Iodothyronines include the classical thyroid hormones
- Thyroxine (T4)
- triiodothyronine (T3)
Furthermore the "non-classical" thyroid hormones, which are partly produced as by-products of thyroid hormone synthesis, partly by regulated deiodination from the classical thyroid hormones. The "non-classical" thyroid hormones include:
- reverse T3 (rT3: biologically inactive form of T3).
- Diiodthyronines (T2: 3,5-Diiodthyronine is an active thyroid hormone with L-thyroxine-like action)
- Monoiodthyronins (T1: the physiological function of these monoiodinated metabolites is still largely unexplained)
- Iodothyroacetates: formed by deamination from iodothyronines. Examples are TRIAC and TETRAC. They show partial agonistic effects to the iodothyronines.
- Thyronamines are formed from iodothyronines by decarboxylation. Their function is largely unknown.
General informationThis section has been translated automatically.
Iodothyronines are lipophilic. They're poorly soluble in plasma. Consequently, they bind to different transport proteins (especially thyroxine-binding globulin, transthyretin and albumin). Iodothyronines are produced by different transport proteins. Iodothyronines are actively transported into the cells by various iodothyronine transporters (transport proteins - see below thyroxine, triiodothronine). Due to this active transport, the intracellular iodothyronine level is higher than in the blood plasma or interstitium.