Leydig cells and seminiferous tubules of human testicular tissue were successfully separated by means of an anti-substance P-antiserum. On incubation with (14C)-testosterone or (14C)-dihydrotestosterone (DHT) it could be shown that besides DHT and 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha-diol) also 5 alpha-androstane-3 beta, 17 beta-diol (3 beta-diol) originated in the tubular compartment. The ratio 3 alpha/3 beta-diol was found to be higher (0.7) here compared to incubation with whole testicular tissue (0.2), indicating that the testicular interstitium influences the metabolism of DHT by the seminiferous tubules.
