Mifepristone (84371-65-3) is a cell-permeable steroid that is a potent antagonist at the progesterone and glucocorticoid receptors.1 It is used clinically as an abortifacient. KD progesterone receptor = 2.6 nM2 and KD glucocorticoid receptor = 0.4 nM3.
1) Cadepond et al. (1997) RU486 (Mifepristone): Mechanisms of action and clinical uses; Annu. Rev. Med. 48 129
2) Terakawa et al. (1988) RU486, a progestin antagonist, binds to progesterone receptors in a human endometrial cancer cell line and reverses the growth inhibition by progestins; J. Steroid Biochem. 31 161
3) Jung-Testas and Baulieu (1983) Inhibition of glucocorticosteroid action in cultured L-929 mouse fibroblasts by RU486, a new anti-glucocorticosteroid of high affinity for the glucocorticoidsteroid receptor; Exp. Cell Res. 147 177