Thyronamines

Thyronamines are a class of hormonally active substances, which are derived from different types of hormones. Iodothyronines are formed. They are formed from different iodothyronines by decarboxylation of the alanine residue. Depending on the degree of iodination, a distinction is made between T0AM - T3AM.

• Thyronamine (T0AM)
• iodothyronamine (T1AM)
• Diiodothyronamine (T2AM)
• triiodothyronamine (T3AM)

Thyronamines do not bind to the thyroid hormone receptor despite a high structural correspondence with thyroid hormones. Instead, they bind to a G-protein-coupling receptor (membrane receptor). For example, T1AM binds to the TAAR receptor TAAR1 (trace amine associated receptor 1). The best-researched TAAR1 receptor is an intracellular amine-activated G protein-coupled receptor (GPCR), which is expressed in various peripheral organs and cells such as the stomach, small intestine, CNS and leukocytes. TAAR binds to endogenous amines. It plays a role in the regulation of neurotransmission of dopamine, norepinephrine, etc.

The human physiological significance of thyronamines is still largely unexplained. An antagonistic effect to TSH has been proven.

1. Chiellini G et al(2015) Design, Synthesis, and Evaluation of Thyronamine Analogues as Novel Potent Mouse Trace Amine Associated Receptor 1 (mTAAR1) Agonists. J Med Chem 58:5096-5107.