3α-HYDROXYSTEROID DEHYDROGENATION IN SUBCELLULAR FRACTIONS OF RAT VENTRAL PROSTATE AND OTHER TISSUES

1965 ◽  
Vol 33 (3) ◽  
pp. 353-363 ◽  
Author(s):  
MARION B. R. GORE ◽  
D. N. BARON
Keyword(s):  
Seminal Vesicle ◽  
Chromatographic Method ◽  
Ventral Prostate ◽  
Rat Tissues ◽  
Soluble Enzyme ◽  
Experimental Conditions ◽  
Widespread Occurrence ◽  
Rat Ventral Prostate ◽  
Soluble Fractions

SUMMARY Dehydrogenation of androsterone, catalysed by both particulate and soluble fractions of rat ventral prostate, has been demonstrated in vitro by spectrophotometric and chromatographic methods. A difference has been observed between dehydrogenases in the particulate and soluble fractions in their acceptance, under uniform experimental conditions, of the 5α and 5β isomers, androsterone and aetiocholanolone, as substrate. The particulate enzyme dehydrogenates androsterone under conditions in which aetiocholanolone is not dehydrogenated, whereas the soluble enzyme utilizes equally androsterone and aetiocholanolone as substrate. An examination of other rat tissues by the chromatographic method has confirmed the widespread occurrence of the soluble dehydrogenase. Particulate dehydrogenase resembling the prostatic enzyme was detected in seminal vesicle and kidney.

scholarly journals Studies on the microsomal sodium-plus-potassium ion-stimulated adenosine triphosphatase system in rat ventral prostate

1969 ◽  
Vol 113 (5) ◽  
pp. 829-836 ◽  
Author(s):  
K. Ahmed ◽  
H G Williams-Ashman
Keyword(s):  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Specific Activity ◽  
Reaction Medium ◽  
Ventral Prostate ◽  
Experimental Conditions ◽  
Enzyme Preparations ◽  
Rat Ventral Prostate ◽  
Stimulation Of

A Mg2++Na++K+-stimulated adenosine triphosphatase (ATPase) preparation was isolated from rat ventral prostate by flotation of microsomal membranes in high-density sucrose solutions. The reaction medium for optimum Na++K+-stimulated ATPase activity was found to be: Na+, 115mm; K+, 7–10mm; Mg2+, 3mm; ATP, 3mm; tris buffer, pH7·4 at 38°, 20mm. The average ΔPi (Mg2++Na++K+ minus Mg2++Na+) was 9μmoles/mg. of protein/hr., representing a 30% increase over the Mg2++Na+-stimulated ATPase activity. At high concentrations, K+ was inhibitory to the enzyme activity. Half-maximal inhibition of Na++K+-stimulated ATPase activity was elicited by ouabain at 0·1mm. The preparation exhibited phosphatase activity towards ribonucleoside triphosphates other than ATP. However, stimulation of Pi release by Na++K+ was observed only with ATP as substrate. The apparent Km for ATP for Na++K+-stimulated activity was about 0·3×10−3m. Ca2+ inhibited only the Na++K+-stimulated ATPase activity. Mg2+ could be replaced by Ca2+ but then no Na++K+ stimulation of ATPase activity was noticed. The addition of testosterone or dihydrotestosterone (17β-hydroxy-5α-androstan-3-one) in vitro at 0·1–10μm under a variety of experimental conditions did not significantly increase the Na++K+-stimulated ATPase activity. The enzyme preparations from prostates of orchidectomized rats, however, exhibited a drastic decrease in the specific activity of Na++K+-stimulated ATPase; these changes were prevented in the orchidectomized rats by injection of testosterone propionate.

FURTHER STUDIES ON A SOLUBLE ANDROGEN-MACROMOLECULAR COMPLEX FROM THE RAT VENTRAL PROSTATE

1970 ◽  
Vol 65 (3) ◽  
pp. 517-524 ◽  
Author(s):  
Olav Unhjem
Keyword(s):  
Hydrogen Atom ◽  
Keto Group ◽  
Ventral Prostate ◽  
Metabolic Inhibitors ◽  
Macromolecular Complex ◽  
Structural Requirements ◽  
Macromolecular Complexes ◽  
Rat Ventral Prostate

ABSTRACT The ability of various steroids and metabolic inhibitors to influence the binding of androgen to soluble macromolecules in the rat ventral prostate was evaluated in vitro. The results obtained revealed some structural requirements of steroids for binding to the macromolecules. An androstane skeleton with the α-configuration of the hydrogen atom at position 5 seemed to be essential for binding as well as a keto group at position 3. N-ethylmaleimide, Na-iodoacetate and p-hydroxymercuribenzoate inhibited the binding of androgen to macromolecules. The androgen-macromolecular complexes appeared to be rather stable at temperatures below 5°C.

scholarly journals Incorporation of Testosterone and 5α-Dihydrotestosterone into Rat Ventral Prostate in vitro

1970 ◽  
Vol 17 (6) ◽  
pp. 453-458 ◽  
Author(s):  
JUN SHIMAZAKI ◽  
JIN SATO ◽  
HISAKO NAGAI ◽  
KEIZO SHIDA
Keyword(s):  
Ventral Prostate ◽  
Rat Ventral Prostate

THE BINDING OF [1,2-3H]TESTOSTERONE WITHIN NUCLEI OF THE RAT PROSTATE

1969 ◽  
Vol 44 (3) ◽  
pp. 323-333 ◽  
Author(s):  
W. I. P. MAINWARING
Keyword(s):  
Molecular Weight ◽  
Equilibrium Dialysis ◽  
Prostate Gland ◽  
Ventral Prostate ◽  
Rat Tissues ◽  
Receptor Complex ◽  
Rat Prostate ◽  
Binding Component

SUMMARY The specificity of the binding of [1,2-3H]testosterone to nuclei of various rat tissues in vivo has been studied. A significant amount of radioactivity was retained in the nuclei of androgen-dependent tissues only, particularly the ventral prostate gland. The bound radioactivity was only partially recovered as [1,2-3H]testosterone; the remainder was identified as [3H]5α-dihydrotestosterone. Efforts were made to characterize the binding component, or 'receptor', in prostatic nuclei. On digestion of nuclei labelled in vivo with [1,2-3H]testosterone, with enzymes of narrow substrate specificity, only trypsin released tritium, suggesting that the receptor is a protein. On the basis of subfractionation studies of labelled nuclei, the receptor is an acidic protein. The androgen—receptor complex could be effectively extracted from the prostatic nuclei in 1 m-NaCl and from the results of fractionations on a calibrated agarose column, the complex has a molecular weight 100,000–120,000. The specificity of the binding of steroids to such 1 m-NaCl extracts in vitro was investigated by the equilibrium dialysis procedure. Under these conditions, the specificity of the binding of [1,2-3H]testosterone demonstrated in vivo could not be simulated. The receptor is probably part of the chromatin complex but its precise intranuclear localization cannot be determined by biochemical procedures alone.

scholarly journals Studies on the form and synthesis of messenger ribonucleic acid in the rat ventral prostate gland, including its tissue-specific stimulation by androgens

1974 ◽  
Vol 137 (3) ◽  
pp. 513-524 ◽  
Author(s):  
W. Ian P. Mainwaring ◽  
Peter A. Wilce ◽  
Allan E. Smith
Keyword(s):  
Prostate Gland ◽  
Sodium Dodecyl ◽  
Ventral Prostate ◽  
Experimental Conditions ◽  
Free System ◽  
Cell Free System ◽  
Messenger Ribonucleic Acid ◽  
Selective Incorporation

1. When prostate polyribosomes are labelled with radioactive precursors in vivo and subsequently dissociated with sodium dodecyl sulphate, a heterogeneous 6–15S RNA species may be identified that possesses all of the distinctive properties of mRNA. 2. Apart from the selective incorporation of 5′-fluoro-orotic acid into this 6–15S RNA component, it is bound by nitrocellulose filters under experimental conditions where only poly(A)-rich species of RNA are specifically retained. Most importantly, however, only the 6–15S RNA fraction is capable of promoting the incorporation of amino acids into peptide linkage in an mRNA-depleted cell-free system derived from ascites-tumour cells. 3. With the development of a simpler method for labelling the total RNA fraction of the prostate gland in vitro, the poly(A)-enriched RNA fraction may be readily isolated by adsorption and elution from oligo(dT)-cellulose. The synthesis of the poly(A)-enriched 6–15S RNA fraction is stringently controlled by androgens in a highly tissue- and steroid-specific manner. 4. From an analysis of the proteins synthesized in the ascites cell-free system in the presence of the poly(A)-rich RNA fraction, it appears that protein synthesis in the prostate gland is stimulated in a rather general way, even during the earliest phases of the androgenic response. This conclusion may require modification when more specific means of analysis are available than those used in the present investigation. 5. The implications of these findings to the mechanism of action of androgens are discussed.

Cell surface modifications in the epithelium of rat ventral prostate during adaptation to in vitro conditions: An ultrastructural study

In Vitro ◽  
1984 ◽  
Vol 20 (3) ◽  
pp. 216-228 ◽  
Author(s):  
Frederick B. Merk ◽  
Paul W. L. Kwan ◽  
Stanley Spilman ◽  
Louis Terracio ◽  
William H. J. Douglas
Keyword(s):  
Cell Surface ◽  
Ultrastructural Study ◽  
Surface Modifications ◽  
Ventral Prostate ◽  
Rat Ventral Prostate

scholarly journals Regulation of Rat DOC-2 Gene during Castration-Induced Rat Ventral Prostate Degeneration and Its Growth Inhibitory Function in Human Prostatic Carcinoma Cells*

Endocrinology ◽  
1998 ◽  
Vol 139 (8) ◽  
pp. 3542-3553 ◽  
Author(s):  
Ching-Ping Tseng ◽  
Brent D. Ely ◽  
Yingming Li ◽  
Rey-Chen Pong ◽  
Jer-Tsong Hsieh
Keyword(s):  
Prostatic Carcinoma ◽  
Ventral Prostate ◽  
Ribonuclease Protection Assay ◽  
Experimental Conditions ◽  
Complementary Dna ◽  
Stable Transfectants ◽  
Isolation And Characterization ◽  
Growth Inhibitory ◽  
Rat Ventral Prostate ◽  
Prostatic Epithelium

Abstract Androgen is a mitogen as well as a morphogen for prostatic epithelium. However, the detailed mechanisms of these distinct androgenic actions have not yet been delineated. Therefore, we employed differential display PCR to unveil any potential genes that may be involved in these processes. In this study, we report the isolation and characterization of two alternative splicing forms (p82 and p59) of C9 complementary DNA, the rat homolog of the human deletion of ovarian carcinoma 2 (DOC-2) gene and mouse p96 phosphoprotein, from rat ventral prostate (VP). We found that C9 was up-regulated in rat VP after castration, suggesting that C9 may be regulated by androgen receptor directly or indirectly during prostate degeneration. A similar regulatory pattern was also observed in both the seminal vesicle and dorsolateral prostate, but not in the coagulating gland or other androgen-independent organs. Immunohistochemical analysis of rat VP demonstrated that C9 is detected in the basal epithelia and surrounding stromal cells after prolonged castration. Ribonuclease protection assay and Western blot analysis revealed that p59 is the predominant C9 isoform in rat VP. To unveil the function of C9 in cell growth, we transfected p59 complementary DNA into the C4-2 cells, a derivative of the LNCaP prostatic carcinoma cell line. The p59 stable transfectants exhibited a slower growth rate and an increase in the cell fraction in the G1 phase under our experimental conditions. These data indicate that C9-p59 has growth inhibitory activity for prostatic epithelial cells. Taken together, our results suggest that C9 is up-regulated during prostate degeneration process and may play an active role in the proliferation and differentiation of prostatic epithelium.

scholarly journals Phosphate-stimulated breakdown of 5′-methylthioadenosine by rat ventral prostate

1969 ◽  
Vol 115 (2) ◽  
pp. 241-247 ◽  
Author(s):  
A E Pegg ◽  
H G Williams-Ashman
Keyword(s):  
Inorganic Phosphate ◽  
Ventral Prostate ◽  
Soluble Enzyme ◽  
Phosphate Ions ◽  
Rat Ventral Prostate ◽  
Absolute Requirement ◽  
Mammalian Tissues ◽  
Nucleoside Metabolism ◽  
Nucleoside Phosphorylases

A soluble enzyme preparation catalysing the release of adenine from 5′-methylthioadenosine was purified some 30-fold from extracts of the rat ventral prostate. This reaction was completely dependent on addition of inorganic phosphate ions to the assay medium. This absolute requirement for phosphate ions suggests a phosphorolytic cleavage mechanism. After acid treatment, the other product of the reaction appeared to be 5-methylthioribose. The actions of some other well-characterized enzymes of nucleoside metabolism of 5′-methylthioadenosine were also investigated; purified purine nucleoside phosphorylases from calf spleen and human erythrocytes did not attack 5′-methylthioadenosine. The role of 5′-methylthioadenosine in mammalian tissues is discussed.

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