Dihydrotestosterone Receptors in the Human Prostate. I. Nuclear Concentration in Normal, Benign, and Malignant Tissues

Abstract

A technique was standardized to measure nuclear dihydrotestosterone receptors in human prostate. Normal, hyperplastic (BPH), and cancer tissues were homogenized and the homogenate centrifuged at 600 g × 10 min; the pellet was purified on sucrose density gradient. Purified nuclei were extracted with 0.4 M KC1. The nuclear extract was then incubated in the presence of [³H]dihydrotestosterone (DHT) at 4°C for 20 hr. Competition studies with different steroids indicated a high specificity of the receptor towards DHT and no affinity towards progesterone and 17β-estradiol. Isolation and purification of [³H]DHT after its incubation in the presence of the KC1 nuclear extract indicated that no significant degradation of the hormone occurred during incubation. The number of binding sites measured was 8.5 ± 0.77 fmol/mg protein(mean ± SEM) for normal, 38.6 ± 5.9 for BPH, and 79.9 ± 21.9for cancer. The possible clinical application of these results will require a long-term follow-up of the hormonal responsiveness of the prostatic-cancer patients investigated.