Androgen metabolism by rat epididymis: metabolic conversion of 3H-dihydrotestosterone in vivo and in vitro.

Abstract

Following intramuscular injection of functionally hepatectomized 24-hr castrated rats with tritiated 5α-androstane- 17β-ol-3-one (3H-DHT), the androgenic metabolites found in the different segments of epididymis were qualitatively similar to those formed after incubation in vitro. Approximately 50% of the radioactivity consisted of unmetabolized DHT in both experiments. In the in vivo investigation, 5α-androstane-3α-ol-17-one (androsterone) and 5α-androstane-3α,17β-diol (3β-diol) were the main metabolites, each constituting approximately 10% of the total radioactivity. In addition, 5α-androstane-3β,17β-diol (3β-diol), 5α-androstane-3,17-dione (5α-A-dione), some A16 compounds, and a large polar fraction were demonstrated. No significant difference in the metabolic pattern was observed between caput and cauda epididymidis. After incubation in vitro, androsterone was undetectable in the caput and only negligible amounts were present in the cauda epididymidis. 3α-Diol was the main metabolite in both the caput...