ANDROGEN BINDING SUBSTANCES IN RAT VENTRAL PROSTATE

1969 ◽  
Vol 61 (1_Suppl) ◽  
pp. S42
Author(s):  
Olav Unhjem
1983 ◽  
Vol 99 (1) ◽  
pp. 51-61 ◽  
Author(s):  
P. Davies

Rat ventral prostate nuclei contain androgen-binding sites which are susceptible or resistant to excision by endonucleolytic action. Those which were susceptible were associated both with oligonucleosomal and subnucleosomal particles. The sedimentation profile characteristic of a nuclear androgen-receptor complex could be obtained by exhaustive nucleolytic digestion or by treatment of fractions with KCl (0·6 mol/l). Androgen-binding sites resistant to DNAase I were also resistant to KCl, whereas those sites resistant to micrococcal nuclease were partially extractable with KCl. Nuclease-resistant sites could be extracted with heparin (10 mg/ml). Androgen–receptor complexes obtained from nuclease-sensitive or nuclease-resistant regions by extraction with KCl or heparin were indistinguishable by routine sedimentation analysis.


1970 ◽  
Vol 65 (3) ◽  
pp. 525-532 ◽  
Author(s):  
Olav Unhjem

ABSTRACT The presence of a 3α-ketosteroid oxidoreductase in the rat ventral prostate cytoplasm has been demonstrated. The enzyme was confined to the 105 000 × g supernatant fraction with very little activity in the mitochondrial-microsomal fraction. Addition of NADPH2 was necessary for the enzymatic reaction to proceed. The enzymatic activity was lost when supernatant fractions were dialysed against 0.1 m Tris-HCl buffer, pH 7.4 or when chromatographed by gel filtration using the same buffer. When either L-cysteine, reduced glutathione, 2-mercaptoethanol or EDTA was added to the buffer, the enzymatic activity was preserved. The molecular weight of the enzyme was calculated to be 40 000–50 000. 3H-5α-dihydrotestosterone associates with macromolecules in the 105 000 × g supernatant fraction which are of two molecular sizes (60 000–70 000 and ∼ 200 000). These complexes could not be demonstrated by gel filtration using buffers containing either reduced glutathione, 2-mercaptoethanol or EDTA. By using L-cysteine, the small molecular complex was preserved.


1980 ◽  
Vol 186 (3) ◽  
pp. 641-647 ◽  
Author(s):  
Y A Lefebvre ◽  
Z Novosad

A nuclear-envelope fraction was isolated from the rat ventral prostate which is virtually free of DNA and contains little RNA or plasma membrane. Isolation of this nuclear-envelope fraction after incubation of purified nuclei with radioactive dihydrotestosterone results in labelling of the membrane. More binding of dihydrotestosterone is observed after incubations at 22 degrees C for 17 h than at 4 degrees C for 17 h or at 22 degrees C for 60 min. Scatchard analysis revealed a class of binding sites with KD 8.4 nM. Dihydrotesterone and testosterone were almost equally effective as competitors of labelled dihydrotestosterone binding on the purified nuclear-envelope fraction, whereas diethylstilboestrol was less effective and dexamethasone did not compete well. When the outer membrane of the nuclei was removed with Triton X-100, a 24% decrease in specific binding of androgens was observed. Castration 24 h before preparation of nuclei resulted in loss of the androgen binding to the membrane.


1969 ◽  
Vol 60 (4) ◽  
pp. 571-578 ◽  
Author(s):  
Olav Unhjem ◽  
Kjell J. Tveter

ABSTRACT A gel filtration technique has been used for analysing the interaction of testosterone and/or its metabolites with macromolecules in the ventral prostate, rectus abdomonis muscle, liver and kidney from castrated adult male rats. Following administration of (1,2-3H)-testosterone, association of radioactivity with soluble macromolecules was demonstrated in the ventral prostate but not in the other organs analysed. A similar binding was observed when slices of ventral prostate were incubated in vitro with testosterone. When 105 000 × g supernatants from the ventral prostate were incubated with (1,2-3H)-testosterone at 37° C, radioactivity was also recovered associated with macromolecules. No association could be detected when the incubation was performed at 0° C.


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