A reconstituted cell-free system for the specific transfer of steroid–receptor complexes into nuclear chromatin isolated from rat ventral prostate gland

Abstract

1. A system has been developed for the specific transfer of [3H]dihydrotestosterone–receptor complexes into prostatic chromatin in vitro. 2. Under optimum conditions the overall transfer of [3H]dihydrotestosterone into purified chromatin in this reconstituted system is entirely consistent with the results obtained in whole tissue both in vivo and in vitro. 3. The transfer of [3H]dihydrotestosterone into chromatin is tissue-specific and maximal into chromatin isolated from androgen-dependent tissues. 4. The tissue specificity is maintained at two levels: first, in the presence of specific cytoplasmic androgen-receptor proteins; secondly, by the nature and composition of the chromatin itself. 5. Evidence is presented that androgenic steroids in vivo may maintain the tissue-specific nature of chromatin in androgen-dependent tissues by the selective induction of nuclear protein synthesis. 6. The relevance of these findings to the mechanism of action of androgenic steroids is discussed.