DISTRIBUTION OF 5α-DIHYDROTESTOSTERONE IN THE EPIDIDYMIS OF BULL AND BOAR, AND ITS CONCENTRATION IN RAT EPIDIDYMIS AFTER LIGATION OF EFFERENT TESTICULAR DUCTS, CASTRATION AND UNILATERAL GONADECTOMY

Abstract

SUMMARY 5α-Dihydrotestosterone concentrations were appreciably higher than testosterone concentrations in the epididymides of both a bull and a boar. The highest concentration of 5α-dihydrotestosterone was found in the heads of these organs. When tritiated testosterone was injected into a castrated rat most of the radioactivity recovered from the epididymis was present as 5α-dihydrotestosterone. Recrystallization confirmed the identity of this compound. In a separate experiment the concentration of 5α-dihydrotestosterone in the epididymis after castration decreased to unmeasurable amounts in about 27 h. This was not the case when only one testis was removed or when testosterone was injected after castration. Ligation of the efferent ducts of a testis on one side resulted in a lowered 5α-dihydrotestosteron concentration in the epididymis of that side. This finding suggests a possible role of spermatozoa in the metabolism of testosterone to 5α-dihydrotestosterone. However, the presence of 5α-dihydrotestosterone in the epididymis of very young rats without spermatozoa showed that spermatozoa are not required for this metabolism.