UPTAKE AND BINDING OF 5α-DIHYDROTESTOSTERONE IN RAT VENTRAL PROSTATE IN VIVO

1971 ◽  
Vol 67 (2) ◽  
pp. 384-392 ◽  
Author(s):  
Vidar Hansson ◽  
Kjell J. Tveter ◽  
Arne Attramadal
Keyword(s):  
Muscle Tissue ◽  
Intravenous Administration ◽  
Male Rats ◽  
Ventral Prostate ◽  
Long Period ◽  
Rat Ventral Prostate

ABSTRACT Following the intravenous administration of [3H] 5α-dihydrotestosterone to adult castrated male rats, the highest uptake of radioactivity was found in the liver and the prostate, in contrast to the much lower uptake in muscle tissue and blood. The results were essentially the same as after the administration of [3H] testosterone. The uptake in the prostate was, however, retained for a long period of time, while the concentration of radioactivity in the liver decreased rapidly after administration and was already lower than that in the prostate after 30 minutes. After the injection of [3H] 5α-dihydrotestosterone in vivo, the labelled adrogen was found to be associated with macromolecules in the prostatic cytosol and with salt extractable nuclear macromolecules.

FURTHER STUDIES ON THE UPTAKE OF ANDROGEN BY SOME ORGANS OF THE MALE RAT

1970 ◽  
Vol 63 (3) ◽  
pp. 489-498 ◽  
Author(s):  
Kjell J. Tveter
Keyword(s):  
Muscle Tissue ◽  
Specific Activity ◽  
Seminal Vesicles ◽  
Radioactive Material ◽  
Male Rats ◽  
Ventral Prostate ◽  
Supernatant Fraction ◽  
Male Rat

ABSTRACT [1,2-3H]Testosterone with a specific activity of 42.3 Ci/mmole was injected intramuscularly to adult castrated male rats. There was a selective uptake of radioactivity by the prostate, where a high and prolonged accumulation of radioactive material was found, in contrast to the much lower uptake by muscle tissue. The influence of castration on the uptake was investigated. In the ventral prostate, the uptake was 205% higher in animals castrated 24 h previously than in non-castrated animals. The corresponding values for the lateral prostate, the coagulating glands and the seminal vesicles were 120%, 165% and 213% respectively. The uptake by the dorsal prostate was only about 23% higher one day after orchidectomy. The uptake by muscle was apparently not influenced by castration. Following homogenization of the coagulating glands and the dorsal and ventral prostate, some of the radioactivity in the 105 000 × g supernatant fraction 1 h after the administration of [1,2-3H] testosterone in vivo was associated with macromolecules. In the lateral prostate an interaction between radioactive material and soluble macromolecules was only found in vitro.

RNA, PROTEIN AND DNA SYNTHESIS STIMULATED BY TESTOSTERONE, INSULIN AND PROLACTIN IN THE RAT VENTRAL PROSTATE CULTURED IN CHEMICALLY DEFINED MEDIUM

1975 ◽  
Vol 80 (4) ◽  
pp. 761-774 ◽  
Author(s):  
Risto Johansson
Keyword(s):  
Response Times ◽  
Defined Medium ◽  
Ventral Prostate ◽  
Chemically Defined Medium ◽  
Physiological Concentration ◽  
Rat Ventral Prostate ◽  
Organ Type ◽  
High Concentrations ◽  
H Protein

ABSTRACT In an organ type tissue culture of the rat ventral prostate in a chemically defined medium insulin (0.08 IU/ml) stimulated the synthesis of RNA within 6–12 h, the synthesis of protein within 6–12 h and the synthesis of DNA within 2–4 days. Testosterone (10−8 m) stimulated these synthetic processes somewhat more slowly: the synthesis of RNA within 12–24 h, protein within 12–24 h and DNA at 4 days. Rather high concentrations of insulin were needed while testosterone was effective at a physiological concentration. Prolactin (1000 ng/ml) stimulated the synthesis of RNA and protein, but not DNA, when added together with either testosterone or insulin, but was completely ineffective when added alone. The response times resembled those of insulin. The lower concentrations of prolactin were ineffective. Growth hormone, luteinizing hormone and follicle stimulating hormone did not stimulate the synthesis of RNA, protein or DNA even when added with testosterone. The results confirm the findings of the numerous in vivo experiments that the hypophyseal hormone prolactin has a direct effect on the ventral prostate.

scholarly journals The urinary excretion of Nτ-methyl histidine in sheep: an invalid index of muscle protein breakdown

1980 ◽  
Vol 44 (2) ◽  
pp. 129-140 ◽  
Author(s):  
C. I. Harris ◽  
G. Milne
Keyword(s):  
Urinary Excretion ◽  
Muscle Tissue ◽  
Intravenous Administration ◽  
Muscle Protein ◽  
Protein Breakdown ◽  
Reliable Index ◽  
Urinary Recovery ◽  
Main Determinant ◽  
Muscle Protein Breakdown

1. The validity of the urinary excretion of Nτ-methyl histidine (Nτ-MH) in sheep as a measure of the breakdown of muscle protein in vivo was assessed from the urinary recovery of radioactivity following the intravenous administration of Nτ-[14CH3]methylhistidine.2. Recoveries of radioactivity in urine from animals of 4 weeks to 7 years of age were incomplete in 7 d but progressively increased with the age of the animal, becoming almost quantitative (90%) in older animals after recovery for 3 weeks.3. The incomplete urinary recoveries were not due to partial excretion of Nτ-MH in faeces or its oxidation and elimination in expired gases but were related to the presence in muscle of a pool of non-protein-bound Nτ-MH which was several times larger than the expected daily urinary excretion.4. This pool in newly accreted muscle tissue was maintained by retention of some of the Nτ-MH released by breakdown of muscle protein. Hence, only a proportion of the Nτ-MH released from protein breakdown was available for excretion. This proportion increased with the age of the animal and was probably the main determinant of the improved recoveries of radioactivity obtained in urine from older animals.5. The non-protein-bound Nτ-MH in muscle consisted of free Nτ-MH and a dipeptide containing Nτ-MH, the latter comprising on average approximately 82% of the total non-protein-bound Nτ-MH in muscle. This proportion did not change appreciably with the age of the animal.6. The dipeptide appeared to be synthesized in muscle from free Nτ-MH and was not a terminal product of protein breakdown.7. The results show that urinary excretion of Nτ-MH is not a reliable index of muscle protein breakdown in sheep.

scholarly journals Steroid-sensitive gene-1 is an androgen-regulated gene expressed in prostatic smooth muscle cells in vivo

2001 ◽  
Vol 26 (3) ◽  
pp. 175-184 ◽  
Author(s):  
D Marcantonio ◽  
LE Chalifour ◽  
MA Alaoui-Jamali And H T Huynh ◽  
MA Alaoui-Jamali ◽  
MA Alaoui-Jamali ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Mrna Expression ◽  
Muscle Cells ◽  
Ventral Prostate ◽  
Mrna Levels ◽  
Rat Ventral Prostate ◽  
Steroid Sensitive

Steroid-sensitive gene-1 (SSG1) is a novel gene we cloned, found regulated by 17beta-estradiol in the rat uterus and mammary gland, and over-expressed in 7,12-dimethylbenz(a)anthracene-induced rat mammary tumors. We show here that SSG1 mRNA and protein expression are regulated by androgens in the rat ventral prostate. Increases in SSG1 mRNA levels were detected by Northern blotting after 24 h and reached a 27-fold peak 96 h following castration, relative to SSG1 mRNA expression in sham-operated rats. Dihydrotestosterone or testosterone supplementation of castrated rats prevented this rise in SSG1 mRNA. In contrast with SSG1 mRNA expression, SSG1 protein was decreased 16-fold 2 weeks following castration but was at control levels in the prostates of castrated rats receiving dihydrotestosterone or testosterone. Although SSG1 is regulated by androgens in vivo, treatment of LnCap cells with dihydrotestosterone, cyproterone acetate or flutamide did not result in the regulation of SSG1 protein levels in vitro. Immunofluorescence studies show that SSG1 is mainly expressed in prostatic smooth muscle cells. These results indicate that SSG1 is an androgen-regulated gene that is expressed in the smooth muscle component of the rat ventral prostate in vivo.

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.

METABOLISM IN VIVO OF [3H] ANDROSTENEDIONE AND [3H] TESTOSTERONE BY ANDROGEN DEPENDENT TISSUES

1970 ◽  
Vol 65 (4) ◽  
pp. 723-730 ◽  
Author(s):  
Kjell J. Tveter ◽  
Asbjörn Aakvaag
Keyword(s):  
Intramuscular Injection ◽  
Total Activity ◽  
Seminal Vesicles ◽  
Radioactive Material ◽  
Male Rats ◽  
Ventral Prostate ◽  
Supernatant Fraction ◽  
Rectus Abdominis Muscle ◽  
Main Metabolite

ABSTRACT The radioactive material present in the different prostatic lobes and the seminal vesicles was isolated and identified after intramuscular injection of [1,2-3H] testosterone to adult castrated male rats. 5α-Dihydrotestosterone was the main metabolite, representing 70, 72, 49, 56 and 70%, respectively, of the total activity in the ventral, dorsal and lateral prostate, the coagulating glands and the seminal vesicles one hour after the administration of hormone. The corresponding values for unchanged [3H] testosterone were 16, 6.4, 23, 6 and 15%, respectively. In rectus abdominis muscle less than 0.3% was 5α-dihydrotestosterone, while 37% represented unconverted [3H] testosterone. Of the activity in liver, [3H]-testosterone accounted for 0.2%, whereas less than 0.1% was 5α-dihydrotestosterone. One hour after administration of [1,2-3H] androst-4-ene-3,17-dione to adult castrated rats, the uptake of radioactivity in the ventral prostate was about 2.7 times higher than in skeletal muscle. In the ventral prostate, 32% of the total activity present at this time was represented by 5α-dihydrotestosterone, while 3.5% was unmetabolized [3H] androstenedione. The corresponding values for the seminal vesicles were 24 and 3.7%, respectively. In the 105 000 × g supernatant fraction of homogenized ventral prostate tissue, part of the radioactivity was associated with soluble macromolecules one hour after the administration of [3H]-androstenedione.

scholarly journals Testosterone action in the rat ventral prostate. The effects of diethylstilboestrol and cyproterone acetate on the metabolism of [3H]testosterone and the retention of labelled metabolites by rat ventral prostate in vivo and in vitro

1971 ◽  
Vol 125 (1) ◽  
pp. 81-91 ◽  
Author(s):  
J. E. Belham ◽  
G. E. Neal
Keyword(s):  
Cyproterone Acetate ◽  
Prostatic Carcinoma ◽  
Prostate Gland ◽  
Target Organ ◽  
Ventral Prostate ◽  
Nuclear Retention ◽  
Rat Ventral Prostate ◽  
Androgenic Effect

Recent reports have indicated that the prior metabolism of testosterone by the secondary sexual tissues may be necessary for its androgenic effect. The effects of two anti-androgens, diethylstilboestrol and cyproterone acetate (17α-acetoxy-6-chloro-1,2α-methylenepregna-4,6-diene-3,20-dione) used in the chemotherapy of human prostatic carcinoma, have been examined on both the metabolism of testosterone and the retention of its metabolites by the rat ventral prostate gland. Cyproterone acetate was found to inhibit the retention of labelled metabolites of [3H]-testosterone by prostatic nuclei, both in vivo and in vitro. This inhibition appeared to be competitive. In contrast with its effect on nuclear retention of metabolites of testosterone, cyproterone acetate had no significant effect on the metabolism of [3H]testosterone by rat ventral prostate tissue. Diethylstilboestrol similarly had little effect on the metabolism of [3H]testosterone by prostatic tissue, although it did appear partially to inhibit its initial metabolism in all the incubation systems used. Diethylstilboestrol inhibited the nuclear retention of dihydrotestosterone when both [3H]testosterone and diethylstilboestrol were injected intraperitoneally in vivo, but had no effect on dihydrotestosterone retention when both testosterone and diethylstilboestrol were supplied directly to the prostate either in vivo or in vitro. It was concluded that if diethylstilboestrol has an anti-androgenic effect at the level of the target organ as distinct from its effect on androgen production by the testes, then it is probably due to a mechanism differing from that of cyproterone acetate.

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