Influence of steroid-receptor complexes on transcription by human hypertrophied prostatic RNA polymerases.
The effects of 5alpha-dihydrotestosterone-receptor complexes on transcription in human hypertrophied prostate tissue were studied in a cell-free system reconstituted from the various subcellular fractions prepared from specimens of the diseased gland. Two major RNA polymerase species were isolated from human hypertrophied prostate. These were designated A and B and were distinguishable by their preference for divalent cations and their sensitivity to salt and alpha-amanitin. Moreover, RNA polymerase B, but not RNA polymerase A, could effectively transcribe a prostate chromatin template. Any enzyme activity endogenous to some chromatin preparations was shown to be characteristic of RNA polymerase B. 5alpha-Dihydrotestoterone-receptor complexes were transferred into prostatic chromatin both steroid- and tissue-specifically. The association of steroid-receptor complexes with chromatin produced changes in template activity and increased the transcription of the chromatin by exogenous and endogenous RNA polymerase B. With a number of specimens, however, there was considerable variation in accessible cytoplasmic receptor sites, uptake of steroid-receptor complexes by chromatin preparations, the template activity of the chromatin and its response to steroid-receptor stimulation. Nevertheless, the transcription characteristics of human hypertrophied prostatic chromatin appear to be influenced by steroid-receptor complexes, and the extent of the response to added complexes would undoubtedly be governed by pre-existing complexes having had an earlier effect.
D000368:Aged; D000546:Amanitins / Q000494:pharmacology; D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D002843:Chromatin / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D003609:Dactinomycin / Q000494:pharmacology; D013196:Dihydrotestosterone / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000187:drug effects / Q000201:enzymology*; D011470:Prostatic Hyperplasia / Q000201:enzymology*; D011485:Protein Binding; D051381:Rats; D011956:Receptors, Cell Surface / Q000187:drug effects*; D012294:Rifamycins / Q000494:pharmacology; D013154:Spleen / Q000187:drug effects / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*
D000546:Amanitins; D002843:Chromatin; D011956:Receptors, Cell Surface; D012294:Rifamycins; D013196:Dihydrotestosterone; D003609:Dactinomycin; D012321:DNA-Directed RNA Polymerases