Androgen interactions with intact nuclear envelopes from the rat ventral prostate

Abstract

Intact nuclear envelopes containing nuclear pore complexes have been prepared from the rat ventral prostate. The polypeptide profile of the nuclear envelopes from the rat prostate resembled that of nuclear envelopes prepared from the male rat liver. Isolation of the nuclear envelopes after incubation of purified nuclei with radioactive dihydrotestosterone results in labelling of the membrane. More dihydrotestosterone is bound after incubations at 22°C for 18 h than at 2°C for 18 h or 22°C for 2h. Scatchard analysis revealed a class of binding sites with an apparent K d of 46nM. Dihydrotestosterone, testosterone, cyproterone acetate and methyltrienolone were effective as competitors of labelled dihydrotestosterone binding to the nuclear envelopes, while estradiol did not compete. Castration of the rats 24, 48 and 96 h prior to preparation of nuclei resulted in loss of androgen binding to the membranes. Extraction with 0.6 M NaCl resulted in the loss of 72% of the androgen binding.