Similarities between 5alpha-dihydrotestosterone-receptor complexes from human and rat prostatic tissue: effects on RNA polymerase activity.

Protein macromolecules specifically binding [3H]5alpha-dihydrotestosterone ([3H]DHT) have been identified in cytosol and in nuclei prepared from human benign hypertrophic prostate. These macromolecules have similar properties to receptor proteins from other androgen-dependent tissues, as regards sedimentation coefficients on sucrose gradients and steroid specificity. Cytosol preparations from androgen-dependent tissues were able to transfer [3H]DHT in a recoverable protein-bound form to nuclei of other androgen-dependent tissues but not to nuclei of androgen-independent tissues. No transfer of radioactive steroid from cytosol of these latter tissues to any nuclei could be achieved. Labelled cytosol preparations from androgen-dependent tissues could stimulate the RNA polymerase activity of nuclei from androgen-dependent tissues but not that of nuclei from androgen-independent tissues. Cytosol preparations from these latter tissues could not affect RNA polymerase activity. Under suitable ionic conditions, human cytosol preparations containing DHT could stimulate both alpha-amanitin-sensitive and -insensitive RNA polymerase activities of human prostatic nuclei. However, rat ventral prostatic DHT-cytosol protein complexes were equally as efficient in performing this function, suggesting the possible involvement of specific DHT-receptor complexes in this process. It is therfore suggested that receptor molecules from androgen-dependent tissues may not be species specific but may share properties which would facilitate research into the understanding and aetiology of pathological conditions.