MEASUREMENT OF FREE AND OCCUPIED CYTOPLASMIC AND NUCLEAR ANDROGEN RECEPTOR SITES IN RAT VENTRAL PROSTATE GLAND

SUMMARY A method has been developed which allows the estimation of occupied and unoccupied androgen receptor sites in both cytoplasmic and nuclear fractions of rat ventral prostate. The procedure involves precipitation of receptor proteins and incubation of precipitates with labelled 5α-dihydrotestosterone. Uptake of 3H-labelled steroid at 0–4 °C gives an indication of free receptor, whereas binding at a raised temperature (15 °C) allows estimation of occupied receptor. Non-specific binding was measured in the presence of a 100-fold excess of unlabelled 5α-dihydrotestosterone. The exchange method was specific for androgens, and specific binding was detected only in fractions of androgen-dependent tissues. The method can be applied to cytosol, whole nuclei, chromatin and salt-extractable and salt-resistant protein preparations from nuclear fractions, and gives a reliable estimate of total receptor sites when occupied as compared with control measurements of unoccupied sites.

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Optimal radioligand exchange conditions for measurement of occupied androgen receptor sites in rat ventral prostate

Archives of Biochemistry and Biophysics ◽

10.1016/0003-9861(83)90189-3 ◽

1983 ◽

Vol 224 (1) ◽

pp. 49-68 ◽

Cited By ~ 25

Author(s):

Oscar Hechter ◽

Douglas Mechaber ◽

Andrew Zwick ◽

Leroy Arthur Campfield ◽

Bernard Eychenne ◽

...

Keyword(s):

Androgen Receptor ◽

Ventral Prostate ◽

Receptor Sites ◽

Rat Ventral Prostate

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A rapid, specific protocol for determination of available androgen receptor sites in unfractionated rat ventral prostate cytosol preparations

Biochemical and Biophysical Research Communications ◽

10.1016/0006-291x(74)90255-1 ◽

1974 ◽

Vol 61 (3) ◽

pp. 1004-1011 ◽

Cited By ~ 16

Author(s):

Robert W. Boesel ◽

Sydney A. Shain

Keyword(s):

Androgen Receptor ◽

Ventral Prostate ◽

Specific Protocol ◽

Receptor Sites ◽

Rat Ventral Prostate

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Specific binding of androgen and androgen-receptor complex by microsomes from rat ventral prostate

The Journal of Steroid Biochemistry and Molecular Biology ◽

10.1016/0960-0760(90)90354-n ◽

1990 ◽

Vol 37 (5) ◽

pp. 697-705 ◽

Cited By ~ 4

Author(s):

Jaime Steinsapir ◽

Thomas G. Muldoon

Keyword(s):

Androgen Receptor ◽

Specific Binding ◽

Ventral Prostate ◽

Receptor Complex ◽

Rat Ventral Prostate

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

Biochemical Journal ◽

10.1042/bj1660189 ◽

1977 ◽

Vol 166 (2) ◽

pp. 189-198 ◽

Cited By ~ 11

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.

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