Age-related changes in the metabolism of [3H] testosterone in vitro by the epididymis of the immature rat.
We examined the production in vitro of 5 alpha-reduced metabolites from testosterone by the rat epididymis during pubertal maturation. Minced caput and cauda epididymides from 30-,45-, and 55-day-old rats were incubated with [3H] testosterone for 2h. Analysis of the radioactive metabolites revealed both similarities and differences in the metabolic patterns compared to those reported for adult rats. As in adults, 5 alpha-dihydrotestosterone was the most abundant metabolite produced by both epididymal segments at all three ages, and it was formed in larger quantities in the caput epididymidis than in the cauda. However, [3H] testosterone metabolism by the epididymis of the immature rat was characterized by a lower formation of 5 alpha-androstane-3 alpha,17 beta-diol and higher production of 5 alpha-androstane-3,17-dione than in adults. Production of these two metabolites by the caput region increased and decreased respectively, toward adult levels, with increasing age. In addition, the amount of [3H] testosterone metabolized was higher with tissues from prepubertal rats (30 days of age) than with those from rats 55 days of age. These data suggest that testosterone metabolism in the caput begins to change to that of the adult during the period of pubertal maturation but apparently not until later in the cauda epididymidis.
D000367:Age Factors; D000818:Animals; D013196:Dihydrotestosterone / Q000378:metabolism; D004822:Epididymis / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012741:Sexual Maturation; D013739:Testosterone / Q000378:metabolism*
D013196:Dihydrotestosterone; D013739:Testosterone