Oxendolone

Oxendolone (TSAA-291) is a steroidal antiandrogen with partial agonist properties, exhibiting a K_i value of 1.4 nM for the androgen receptor. Oxendolone exerts tissue-specific androgen receptor activity, induces unique androgen receptor conformational changes, and drives differential cofactor recruitment. Oxendolone is recruited to the androgen receptor in a PIAS1-dependent manner. Oxendolone increases levator ani muscle weight in castrated mice. Oxendolone can be used for research on benign prostatic hyperplasia^[1]. In Vitro:Oxendolone (4 h) acts as a partial androgen receptor agonist in COS-7 cells, with activity reaching approximately 50% of the maximal activity of 1 μM dihydrotestosterone (DHT); in the presence of 0.1 μM DHT, it acts as an antagonist^[1].
Oxendolone (0.1 pM-1 μM; 24 h) exhibits tissue-selective androgen receptor agonist activity, with higher relative potency in human skeletal muscle (SkMC) cells (reaching 87.6% of 100 nM DHT activity at 100 nM), whereas in human prostate epithelial (PrEC) cells it is only 47.5% of 100 nM DHT activity (at 100 nM)^[1].
Oxendolone (24 h) induces a unique androgen receptor cofactor recruitment profile in 293T cells, recruiting 12 cofactors (including PIAS1) in a manner distinct from DHT, while recruiting 43 cofactors in a ligand-independent manner that is completely consistent with DHT^[1].
Oxendolone (100 nM; 24 h) enhances its androgen receptor transcriptional activity in 293T cells through forcibly expressed PIAS1^[1]. In Vivo:Oxendolone (3-30 mg/kg; subcutaneous injection; once daily; for 14 consecutive days) exerts tissue-selective androgen receptor modulator activity in castrated male mice, increasing levator ani muscle weight to 78% of the level in normal mice at a dose of 30 mg/kg without increasing prostate or seminal vesicle weight^[1].