In vivo metabolism of 3H-dihydrotestosterone and 3H-androstanediol in adult male rats

Abstract The in vivo uptake and metabolism of 3 H-5α-dihydrotestosterone† and 3 H-5α-androstane-3α, 17β-diol by various tissues of intact adult male rats following a constant infusion of the 3 H-steroid were studied. The 3 H level in the form of DHT, Adiol, 3β-Adiol, A and Adione was measured for plasma, liver, kidney, prostate, seminal vesicles, epididymis, muscle, brain, adrenal and testes. Regardless of which steroid was infused, the pattern of total radioactivity and that in the form of the five 3 H-steroids in the different tissues was the same indicating that equilibrium between DHT and Adiol is rapidly attained. DHT was the predominant metabolite isolated from prostate, seminal vesicles, brain and adrenal extracts. Adiol was the major metabolite isolated from plasma, epidiymis, muscle and testes extracts. DHT and Adiol levels were approximately equal in kidney extracts. 3β-Adiol was the predominant metabolite isolated from the liver and was present in significant amounts in adrenal and testicular extracts. The metabolic clearance rates for DHT and Adiol were 87.2 ± 9.1 and 12.8 ± 1.0 1/24 h /100 g body wt., respectively.