3-iodothyronamine

3-Iodothyronamine (T1AM) is an endogenous thyronamine. It is a high-affinity ligand of the trace amine-associated receptor 1 (TAAR1). T1AM is the most potent endogenous TAAR1 agonist yet discovered. It is also an agonist of the TAAR2 and TAAR5 with similar potency as for the TAAR1 (all in the case of the human proteins). T1AM is not a ligand of the thyroid hormone receptors. However, it is additionally a ligand of various monoamine and other receptors. For instance, it is a muscarinic acetylcholine receptor antagonist.

Activation of TAAR1 by T1AM results in the production of large amounts of cyclic adenosine monophosphate (cAMP). This effect is coupled with decreased body temperature and cardiac output. Wu et al. have pointed out that this relationship is not typical of the endocrine system, indicating that TAAR1 activity may not be coupled to G proteins in some tissues, or that T1AM may interact with other receptor subtypes. T1AM may be part of a signaling pathway to modulate cardiac function, as the compound can induce negative inotropic effects and decrease cardiac output.