scholarly journals Initiation and elongation of polyribonucleotide chains on rat ventral-prostate chromatin transcribed by homologous ribonucleic acid polymerase B.

1977 ◽  
Vol 166 (2) ◽  
pp. 189-198 ◽  
Author(s):  
P Thomas ◽  
P Davies ◽  
K Griffiths
Keyword(s):  
Rna Polymerase ◽  
Rna Synthesis ◽  
Prostate Gland ◽  
Ventral Prostate ◽  
Control Of Gene Expression ◽  
Rat Ventral Prostate ◽  
Associated Proteins ◽  
Ribonucleoside Triphosphate ◽  
Androgenic Steroids ◽  
Transcriptional Process

The characteristics of initiation of RNA synthesis and the elongation of RNA chains on rat ventral-prostate chromatin by RNA polymerase B were investigated by two methods. 1. Initiation was carried out under low-salt conditions with three ribonucleoside triphosphates, and elongation was begun in the absence of reinitiation by the addition of the fourth ribonucleoside triphosphate and increasing the salt concentration. 2. Stable initiation complexes were formed by preincubation of enzyme with template at 37 degrees C, elongation was started by the addition of all four ribonucleoside triphosphates and reinitiation or spurious RNA synthesis was prevented by rifamycin AF/013. The latter method gave more reliable results. The dependence of those parameters on the androgenic status of the animal was studied. During the first 24h after castration, elongation was mainly affected, whereas after 72h a smaller number of initiation sites for RNA polymerase B on chromatin was evident. Considerable diurnal variations in the various parameters were observed. Changes in the relative concentrations of the chromatin-associated proteins were also observed after castration. In the rat ventral-prostate gland androgenic steroids may not only influence one stage of the transcriptional process, but may affect many factors involved in the control of gene expression.

scholarly journals Studies on the solubilized ribonucleic acid polymerase from rat ventral prostate gland

1971 ◽  
Vol 123 (4) ◽  
pp. 619-628 ◽  
Author(s):  
W. I. P. Mainwaring ◽  
F. R. Mangan ◽  
B. M. Peterken
Keyword(s):  
Time Course ◽  
Prostate Gland ◽  
Exchange Chromatography ◽  
Ventral Prostate ◽  
Enzyme Preparations ◽  
Rat Ventral Prostate ◽  
Rapid Stimulation ◽  
Androgenic Steroids

1. By using ultrasonic treatment in media of high ionic strength, the RNA polymerase activities associated with prostatic nuclei and nucleoli can be completely solubilized. Such enzyme preparations are entirely dependent on the provision of added DNA for full activity. 2. The solubilized enzymes from the nucleolar and extranucleolar regions can be separated by ion-exchange chromatography. 3. Based on differences in the optimum DNA templates, pH optima and the effects of ammonium sulphate on the activities in vitro, Mn2+- and Mg2+-specific enzymes are associated with both the nucleolar and extranucleolar regions of prostatic nuclei. 4. Androgenic hormones administered in vivo have a particularly pronounced effect on the activity of Mg2+-dependent enzyme associated with the isolated prostatic nucleolus. 5. Time-course experiments in vivo show that androgens induce a rapid stimulation of the solubilized Mg2+-dependent nucleolar enzyme before a pronounced activation of nucleolar chromatin can be measured. 6. The implications of these findings to the mechanism of action of androgenic steroids are discussed.

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

1971 ◽  
Vol 125 (1) ◽  
pp. 285-295 ◽  
Author(s):  
W. I. P. Mainwaring ◽  
Brenda M. Peterken
Keyword(s):  
Prostate Gland ◽  
Ventral Prostate ◽  
Free System ◽  
Tissue Specific ◽  
Receptor Complexes ◽  
Rat Ventral Prostate ◽  
Reconstituted System ◽  
Androgenic Steroids

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.

Biomarker analysis demonstrates a hypoxic environment in the castrated rat ventral prostate gland

2001 ◽  
Vol 81 (3) ◽  
pp. 437-444 ◽  
Author(s):  
Ahmad Shabsigh ◽  
Mohamed A. Ghafar ◽  
Alexandre de la Taille ◽  
Martin Burchardt ◽  
Steven A. Kaplan ◽  
...  
Keyword(s):  
Prostate Gland ◽  
Ventral Prostate ◽  
Rat Ventral Prostate ◽  
Hypoxic Environment ◽  
Biomarker Analysis

scholarly journals Cascade Induction of c-fos, c-myc, and Heat Shock 70K Transcripts during Regression of the Rat Ventral Prostate Gland

1988 ◽  
Vol 2 (7) ◽  
pp. 650-657 ◽  
Author(s):  
Ralph Buttyan ◽  
Zahra Zakeri ◽  
Richard Lockshin ◽  
Debra Wolgemuth
Keyword(s):  
Heat Shock ◽  
Prostate Gland ◽  
Ventral Prostate ◽  
Rat Ventral Prostate

scholarly journals The androgenic regulation of the activities of enzymes engaged in the synthesis of deoxyribonucleic acid in rat ventral prostate gland

1975 ◽  
Vol 152 (1) ◽  
pp. 1-16 ◽  
Author(s):  
P S Rennie ◽  
E K Symes ◽  
W J Mainwaring
Keyword(s):  
Dna Replication ◽  
Dna Polymerase ◽  
Hormonal Regulation ◽  
Prostate Gland ◽  
Experimental System ◽  
Physicochemical Characteristics ◽  
Ventral Prostate ◽  
Receptor System ◽  
Rat Ventral Prostate ◽  
Androgenic Regulation

1. The restoration of mitosis and growth of the prostate gland of castrated animals by androgens provides a favourable experimental system for studying the hormonal regulation of enzymes engaged in DNA replication. 2. Many DNA polymerase activities were identified in the prostate gland, but only a 9S form with a particular preference for denatured DNA as template was conspicuously enhanced by androgenic stimulation. 3. Thymidine kinase also provided a sensitive indicator of the hormonal regulation of DNA replication, and on electrophoretic criteria, one discrete form of the enzyme appeared precisely with the onset of mitoris. 4. Evidence is presented to support the view that DNA ligase activity is intimately associated in the process of DNA replication in the prostate gland. 5. A spectrum of deoxyribonuclease activities is present in the prostate gland, but only one form (pI7.0) can safely be said to be implicated in the process of DNA replication. 6. Androgenic stimulation of the prostate gland leads to the appearance of a component capable of denaturing or unwinding prostate DNA. This component is seemingly distinct from RNA or DNA polymerase activities on the basis of several distince physicochemical characteristics. 7. The conspicuous feature of all the changes in enzyme activities evoked by androgens in the prostate gland is their acute tissue- and steroid-specificity. Such changes could not be mimicked in liver or spleen and the regulatory role of androgens could not be simulated by other classes of steroid hormones. Particularly on the basis of studies with the anti-androgen cyproterone acetate, it is concluded that the changes are initially mediated by the androgen-receptor system and the high-affinity binding of 5α-dihydrotestosterone in the prostate gland. 8. The results are discussed in the context of the mechanism of action of androgens.

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