3-Iodothyronamine (T
1AM) is an
endogenous thyronamine. T
1AM is a high-affinity
ligand for the
trace amine-associated receptor TAAR1 (TAR1, TA1), a recently discovered
G protein-coupled receptor. T
1AM is the most potent TAAR1 agonist yet discovered. Activation of TAAR1 by T
1AM results in the production of large amounts of 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 T
1AM may interact with other receptor subtypes.