ML224(NCGC00242364; ANTAG3) is a selective TSHR inverse agonist; inhibits TSH-stimulated cAMP production with an IC50 = 2.3 μM.IC50 value: 2.3 uM [1]Target: TSHR agonistin vitro: ANTAG3 was selective for TSHR inhibition; half-maximal inhibitory doses were 2.1 μM for TSHR and greater than 30 μM for LH and FSH receptors [2]. in vivo: In mice treated with TRH, ANTAG3 lowered serum free T4 by 44% and lowered mRNAs for sodium-iodide cotransporter and thyroperoxidase by 75% and 83%, respectively. In mice given M22, ANTAG3 lowered serum free T4 by 38% and lowered mRNAs for sodium-iodide cotransporter and thyroperoxidase by 73% and 40%, respectively [2].
References:
[1]. Huang W, et al. Identification of Thyroid Stimulating Hormone Receptor Inverse Agonists. Probe Reports from the NIH Molecular Libraries Program
[2]. Neumann S, et al. A selective TSH receptor antagonist inhibits stimulation of thyroid function in female mice. Endocrinology. 2014 Jan;155(1):310-4.