Effect of long-term hyperprolactinemia on the prolactin receptor content of the rat ventral prostate

The Prostate ◽  
1985 ◽  
Vol 6 (3) ◽  
pp. 277-283 ◽  
Author(s):  
M. A. Blankenstein ◽  
J. -De Bolt Vries ◽  
A. Coert ◽  
H. Nievelstein ◽  
F. H. Schröder
Keyword(s):  
Prolactin Receptor ◽  
Ventral Prostate ◽  
Rat Ventral Prostate

scholarly journals Immunochemical characterization of the androgen-dependent spermine-binding protein of the rat ventral prostate

1984 ◽  
Vol 218 (2) ◽  
pp. 563-571 ◽  
Author(s):  
R A Hiipakka ◽  
C Chen ◽  
K Schilling ◽  
A Oberhauser ◽  
A Saltzman ◽  
...  
Keyword(s):  
Solid Phase ◽  
Binding Protein ◽  
Deae Cellulose ◽  
Ventral Prostate ◽  
Rat Tissues ◽  
Secretory Product ◽  
Prostatic Fluid ◽  
Rat Ventral Prostate ◽  
Significant Difference

A solid-phase radioimmunoassay was developed to measure the level of the androgen-dependent spermine-binding protein (SBP) in the cytosol fraction of the rat ventral prostate during endocrine manipulation. The concentration of SBP and immunologically cross-reacting material (CRM) in the ventral prostate was at least 5000 times higher than the level of CRM detected in rat serum or cytosol from other rat tissues. Cytosol from the ventral prostate of intact rats was separated by DEAE-cellulose chromatography into three major fractions of CRM. One of these fractions corresponded to the elution position of SBP. Cytosol prepared from rats 48 h after castration lacked SBP and one of the two other fractions of CRM. This loss coincided with an increase in CRM in the remaining fraction. No significant difference was detected in the total level of CRM when intact and 48 h-castrated rats were compared. Injection of rats with 5 alpha-dihydrotestosterone (DHT) immediately after castration prevented these changes in the profile of CRM. Several proteins cross-reacting with antibodies to purified SBP were detected in cytosol by using an immunoblot procedure. The highest-Mr band corresponded to SBP. The effect of short- and long-term castration and subsequent DHT treatment on CRM was studied by using the immunoblot technique. Short-term castration (2 days) led to the disappearance of CRM coinciding with SBP (Mr 35 000-38 000) and an increase in smaller forms of CRM (Mr 24 000 and 22 000). Injection of rats with DHT 2 days after castration led to the reappearance of CRM corresponding to SBP, which returned to normal levels within 4 to 5 days of treatment. Long-term castration (up to 14 days) led to a gradual disappearance of all CRM; subsequent DHT treatment led to the reappearance of all forms of CRM and normal levels were attained within 5 days. We have identified SBP and the various forms of CRM as a secretory product of the rat ventral prostate by immunohistochemical staining and by DEAE-cellulose fractionation of prostatic fluid. Prostatic fluid is rich in proteolytic activity and these proteinases may be responsible for processing SBP to small forms of CRM.

THE EFFECT OF OESTRADIOL-3N-BIS-(2-CHLOROETHYL)CARBAMATE-17β-PHOSPHATE (ESTRACYT®) ON THE 5α-REDUCTASE IN THE RAT VENTRAL PROSTATE

1975 ◽  
Vol 80 (1) ◽  
pp. 188-198 ◽  
Author(s):  
Per Aage Høisaeter
Keyword(s):  
Reductase Activity ◽  
Inhibitory Effect ◽  
Term Treatment ◽  
Significant Inhibition ◽  
Ventral Prostate ◽  
Rat Ventral Prostate ◽  
Long Term Treatment

ABSTRACT The ventral prostate of the rat both after in vitro incubation and in vivo experiments was found to contain appreciable 5α-reductase activity, whilst a very low activity was registered in the diaphragm and liver. Neither Estracyt® nor LEO275 (Estracyt® without the phosphate group in position 17 of the oestradiol moiety) had an inhibitory effect on the enzyme activity after in vitro incubation but equivalent amounts of oestradiol-17β and oestradiol-17β-phosphate significantly reduced 5α-reductase activity. When Estracyt® was injected in vivo no influence on activity was registered in "short term" experiments while a significant inhibition was found after "long term" treatment in vivo. Possible explanations for this "long term" effect of Estracyt® on 5α-reductase activity are discussed.

Further observations on the autoregulation of the prolactin receptor in rat ventral prostate explants

1987 ◽  
Vol 114 (3) ◽  
pp. 426-432
Author(s):  
H. Rui ◽  
I. Brekke ◽  
P. A. Torjesen ◽  
K. Purvis
Keyword(s):  
Protective Action ◽  
Prolactin Receptor ◽  
Human Growth ◽  
Ventral Prostate ◽  
Synthesis Inhibitor ◽  
Rat Ventral Prostate ◽  
Preliminary Communication ◽  
Lactogenic Hormones ◽  
Ovine Prolactin

Abstract. In confirmation and extension of an earlier preliminary communication, ovine prolactin was found to elevate prolactin binding by approximately 100% in rat ventral prostate explants incubated for 20 h in vitro. A stimulation was observed with low doses of ovine hormone (150 μg/l) which, from available data on the relative biological potencies, could be considered equivalent to the upper limit of the physiological range of endogenous rat prolactin. The response was associated with a lag period of 3–6 h. The effect could be obtained with other lactogenic hormones, including human and rat prolactin and human growth hormone, but not with non-lactogenic hormones such as insulin, hCG, corticosterone, testosterone or oestradiol. The prostaglandin synthesis inhibitor, indomethacin, and the Ca2+-antagonist, verapamil, could not counteract the increase in prolactin binding induced by prolactin treatment, nor could dibutyryl cyclic AMP alone mimic the response. These data suggest that prostaglandins, Ca2+ or cAMP do not mediate the alteration in receptor binding. Furthermore, inhibition of lysosome activity by chloroquine could not alone increase the prolactin binding in the control tissues, suggesting that up-regulation does not simply reflect a protective action of prolactin on receptor degradation.

Characterization and cloning of androgen-repressed mRNAs from rat ventral prostate

1987 ◽  
Vol 147 (1) ◽  
pp. 196-203 ◽  
Author(s):  
Jocelyne G. Léger ◽  
Michael L. Montpetit ◽  
Martin P. Tenniswood
Keyword(s):  
Ventral Prostate ◽  
Rat Ventral Prostate

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.

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