NCGC00161856

NCGC00161856 is identified as the first small-molecule ligand and inverse agonist of the thyroid-stimulating hormone receptor (TSHR) . It inhibits basal cAMP production in HEK-EM 293 cells that stably express TSHRs, with a half-maximal inhibitory concentration (IC50) of 3.0 μM. This means that NCGC00161856 effectively reduces the constitutive activity of TSHR, which is the receptor's activity in the absence of its natural ligand (thyroid-stimulating hormone, TSH) .