Davies J H, Shearer R J, Rowlands M G, Poon G K, Houghton J, Jarman M, Dowsett M
Department of Urology, St. Georges Hospital, London, England, UK.
J Enzyme Inhib. 1992;6(2):141-7. doi: 10.3109/14756369209040745.
The steroidal aromatase inhibitor, 4-hydroxyandrost-4-ene-3,17-dione (4OHA) and its metabolites, 4-hydroxytestosterone (4OHT), 3 beta,17-dihydroxy-5 alpha-androstan-4-one (metabolite A) and 3 alpha, 17-dihydroxy-5 beta-androstan-4-one (metabolite B) were evaluated as inhibitors of the human prostatic 5 alpha-reductase enzyme and for binding to the rat prostatic androgen receptor. 4OHA and 4OHT were weak inhibitors of 5 alpha-reductase with IC50 values of 15-29 microM. Metabolites A and B had no significant inhibitory activity. 4OHA and metabolites A and B bound weakly to the androgen receptor. The binding affinities (RBA) relative to mibolerone (RBA = 100) were 0.085, 0.485 and 0.016, respectively. However, 4OHT (RBA = 75) was a more potent binder than the endogenous androgen 5 alpha-dihydrotestosterone (RBA = 66). The ability of these metabolites, in particular 4OHT, to bind to the androgen receptor may explain the in vivo androgenic activity of 4OHA.
甾体芳香化酶抑制剂4-羟基雄甾-4-烯-3,17-二酮(4OHA)及其代谢产物4-羟基睾酮(4OHT)、3β,17-二羟基-5α-雄甾烷-4-酮(代谢产物A)和3α,17-二羟基-5β-雄甾烷-4-酮(代谢产物B)被评估作为人前列腺5α-还原酶的抑制剂以及与大鼠前列腺雄激素受体的结合能力。4OHA和4OHT是5α-还原酶的弱抑制剂,IC50值为15 - 29微摩尔。代谢产物A和B没有显著的抑制活性。4OHA以及代谢产物A和B与雄激素受体的结合较弱。相对于米勃酮(RBA = 100)的结合亲和力(RBA)分别为0.085、0.485和0.016。然而,4OHT(RBA = 75)比内源性雄激素5α-双氢睾酮(RBA = 66)具有更强的结合能力。这些代谢产物,特别是4OHT,与雄激素受体结合的能力可能解释了4OHA的体内雄激素活性。