Androgen metabolism by rat epididymis 4. The formation of conjugates

The ability to form androgen conjugates and the hormone dependency of the conjugating enzymes have been studied in the rat epididymis.Following the in vitro incubation of ³H-testosterone with epididymal slices from intact and castrated rats, the radioactivity recovered was partitioned between water and ether. Examination of the water soluble radioactivity demonstrated the presence of glucuronides and sulfates. The total radioactivity in the conjugate fraction was the same for both intact and castrated animals. However, castrated rats showed a 3-fold increase in the glucuronide fraction with a corresponding decrease in the formation of sulfates. Characterization of the ether soluble radioactivity after solvolysis of the conjugate fraction from castrated animals, showed DHT (17β-hydroxy-5α-androstan-3-one) and 3α-diol (5α-androstane-3α,17β-diol) to be the main metabolites. After β-glucuronidase hydrolysis of the same, only 3α-diol could be demonstrated at a significant level, although traces of DHT and δ¹⁶ compounds were present.Corresponding hydrolysis of the water phase from incubation of epididymis from intact rats, demonstrated a marked quantitative difference. Here approximately 40% of the conjugated aglycones consisted of Δ¹⁶ compounds, whilst only abot 12% was comprised of 3α-diol. The preferential conjugation of DHT and 3α-diol to a sulfate radical was demonstrated in both intact and castrated rats. Since the conjugated Δ¹⁶ compounds were detected only in the epididymis from intact animals, it is possible that these are formed by the spermatozoa.