In vivo metabolism of 3H-testosterone in adult male rats: effects of estrogen administration.
The metabolism of testosterone (T) was studied in normal adult male rats using a constant infusion of trace amounts of the 3H-steroid into a tail vein for 3 h in order to attain a state of equilibrium. Samples of plasma, liver, kidney, prostate, seminal vesicles and muscle were analysed for 3H-testosterone, 3H-5alpha-dihydrotestosterone (5alphaDHT) and 3H-5alpha-androstanediol (Adiol). When compared to the 3H-T level in plasma there were high levels of 3H-T in kidney and of 3H-5alphaDHT in prostate and seminal vesicles. Intraperitoneal estradiol valerate administration (100 mug/day) for 4 days decreased and 3H-5alphaDHT levels in the prostate and seminal vesicles. The estrogen administration increased the T metabolic clearance rate from 17.5 1/24 h/100 g body wt to 22.6 1/24 h/100 g body wt.
D015113:Androstane-3,17-diol / Q000378:metabolism; D000818:Animals; D013196:Dihydrotestosterone / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D008657:Metabolic Clearance Rate; D009132:Muscles / Q000378:metabolism; D011467:Prostate / Q000378:metabolism; D051381:Rats; D012669:Seminal Vesicles / Q000378:metabolism; D013739:Testosterone / Q000097:blood / Q000378:metabolism*
D013196:Dihydrotestosterone; D015113:Androstane-3,17-diol; D013739:Testosterone; D004958:Estradiol