11-Beta-hydroxyandrostenedione (4-Androsten-11β-ol-3,17-dione) is a steroid mainly found in the the adrenal origin (11β-hydroxylase is present in adrenal tissue, but absent in ovarian tissue). 11-Beta-hydroxyandrostenedione is a 11β-hydroxysteroid dehydrogenase (11βHSD) isozymes inhibitor. As 4-androstenedione increases, measuring plasma 11-Beta-hydroxyandrostenedione can distinguish the adrenal or ovarian origin of hyperandrogenism^[1][2]. IC50 & Target: 11β-hydroxysteroid dehydrogenase (11βHSD) isozymes^[2] In Vitro: In order to establish that this conversion is catalysed by the lyase activity of CYP17A1, 21-deoxycortisol (21dF) and 21-deoxycortisone (21dE) is assayed within the LNCaP cell line. Upon the transfection of CYP17A1, 11-Beta-hydroxyandrostenedione (11OHA4)-pathway metabolites increase, 21dF and 21dE are in fact metabolised to 11-Beta-hydroxyandrostenedione and 11-ketoprogesterone (11KP4) by CYP17A1, respectively^[2]. In Vivo: The plasma concentration of 11-Beta-hydroxyandrostenedione (11beta-hydroxy-4-androstene-3,17-dione) is very high in 21-hydroxylase deficiency, Cushing's syndrome, and hyperandrogenism of adrenal origin, and very low in congenital 11-hydroxylase deficiency and adrenal insufficiency. Thus, when plasma 4-androstenedione is elevated, it is useful to measure the plasma 11-Beta-hydroxyandrostenedione level in order to determine the adrenal or ovarian origin of the hyperandrogenism^[1].