Biochemistry of the nonhuman primate prostate and seminal vesicles. II. Molecular weights of soluble proteins

The molecular weights of the soluble proteins from cranial and caudal prostate and seminal vesicle tissues of several species of nonhuman primates were separated by electrophoresis. The tissues of animals belonging to the genus Macaca were found to be similar and are compared to those of other species. The molecular weights of these proteins are discussed with regard to known concentrations of prostate and seminal vesicle proteins.

Extraction of androgen-receptor complexes from regions of rat ventral prostate nuclei sensitive or resistant to nucleases

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.

[R 1881 binding receptor and DHT concentrations in prostatic cytosol]

R 1881 binding receptor and DHT concentrations in human prostatic cytosol were assayed in surgically removed prostatic tissues of benign prostatic hyperplasia (BPH) and of the normal prostate. The normal prostates were obtained from totally cystectomized male patients with bladder cancer. Cytosols were incubated with 0.25--8.0 nM (6 points) of 3H-R 1881 in the presence or absence of excess radioinert R 1881 at 4 degrees C for 20 hours, thereafter treated with 0.5% dextran coated charcoal. Specific bindings were analysed in the form of scatchard plot analysis. Cytosol DHT levels were determined by radioimmunoassay reported previously. Steroid specificity studies revealed that R 1881 binding receptor was inhibited not only by androgens but also by progesterone, however, an addition of 1000 fold excess triamcinolone acetonide (TCA) reduced the inhibition by progesterone. As R 1881-receptor complex was eluted at the void volume of sephacryl S-200 chromatography, the receptor was considered to be 8-9S protein. Cytosol DHT levels were 35.5 +/- 13.6 pg/mg cytosol protein in BPH and 18.9 +/- 7.1 pg/mg protein in the normal prostates, showing a significantly higher value in the former (p less than 0.01). Kd and NBS of R 1881 receptor in BPH were 0.73 +/- 0.21 nM and 30.1 +/- 9.0 fmol/mg cytosol protein and those in normal prostate were 0.68 +/- 0.28 nM, 10.2 +/- 4.2 fmol/mg protein, respectively. NBS were also higher in BPH compared to the normal prostate (p less than 0.001). Moreover, DHT levels (y) and NBS (x) showed a significant correlation (y = 0.631 X + 15.764, r = 0.506).(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization and cloning of rat dorsal prostate mRNAs. Androgen regulation of two closely related abundant mRNAs

Electrophoresis of rat dorsal prostate mRNAs on agarose gels containing methyl mercury hydroxide indicates the presence of several highly abundant mRNAs. In vitro translation of the total mRNAs in a cell-free system, followed by polyacrylamide gel electrophoresis, yields protein products including two intense bands corresponding to 23,000 and 21,000 Da. Following castration of rats, these in vitro translation products of dorsal prostate mRNAs are absent. However, the dorsal prostate levels of these two proteins are returned to normal in castrated rats which have received testosterone. In order to investigate these abundant mRNAs of the dorsal prostate, we have constructed double-stranded cDNA clones using poly(A+) RNA extracted from that rat tissue. Clones containing sequences complementary to abundant mRNAs were selected kinetically by colony hybridization with 32P-labeled dorsal prostate cDNA. Further characterization of individual clones was accomplished by restriction mapping and Northern blot analysis. One clone, pM-40, was found to be near full length and was used for further studies. Interestingly, in hybrid-arrested cell-free translation, clone pM-40 completely arrests the translation of both the 23,000- and 21,000-Da protein products indicating close sequence homology between these two proteins. Furthermore, dot hybridization experiments demonstrate that, in the dorsal prostate, the pM-40-specific mRNAs decrease following castration and are restored by testosterone administration. However, the low levels of the same mRNAs in the ventral prostate are not altered by androgen manipulation. Thus, two closely related, androgen-dependent tissues maintain differential regulation of the pM-40 gene(s). This system provides an opportunity to study in two tissues the differential regulation of a gene that may be duplicated or that may code for two separate proteins.

The concentration of zinc in relation to fundamental elements in the diseased human prostate

Studies of the composition of prostatic tissue revealed significant decreases not only of the zinc but also of the potassium concentration, in the cancerous tissue, whereas the nitrogen, phosphorus and magnesium concentrations were within normal limits. The composition of hyperplastic prostatic tissue was similar to the normal except for a tendency towards decreased nitrogen concentration.

Comparative distribution of fibronectin and type III collagen in normal human tissues

The distribution of fibronectin (FN) and type III collagen (IIIC) in normal adult human tissues have been directly compared using immunofluorescence and immunoperoxidase techniques on fresh frozen and formalin-fixed paraffin embedded material. Although in many tissues localisation of these two proteins appeared similar, two major differences were identified: (1) Where the ratio of extracellular matrix to cells is high (e.g. in breast, intestinal submucosa), FN was scanty and present predominantly in association with cells, whether of epithelial, endothelial or mesenchymal origin. IIIC was present diffusely throughout interstitial connective tissue. (2) In the highly specialised vascular beds of spleen and renal glomeruli, FN was abundant and accompanied by little or no IIIC. It is postulated that these differences reflect a generalised more intimate association of FN with cell surfaces and basal laminae which is not always discernible by light microscopy. Proximity of FN and IIIC may nevertheless be important for cell-matrix interactions. It was also noted that "reticulin" fibres as defined by silver impregnation do not all have an identical composition.

Thyrotrophin releasing hormone and related peptides in canine tissues

Thyrotrophin releasing hormone (TRH)-immunoreactive peptides have been quantified in canine serum, hypothalamus, liver, pancreas, adrenal, thyroid, prostate, testis, epididymis and semen by TRH radioimmunoassay, SP-Sephadex C-25 cation exchange chromatography, Sephadex G-10 exclusion chromatography and high pressure liquid chromatography. The total concentration of TRH and TRH-like peptides was highest in the hypothalamus, followed by liver, adrenal, pancreas, thyroid, prostate, epididymis, testis and serum. All of the TRH immunoreactivity (TRH-IR) within extracts of the hypothalamus was due to TRH. On the other hand, nearly all of the TRH-IR of extracts of liver, thyroid, prostate, epididymis, testis and semen was due to TRH-homologous peptides. Adrenal and pancreatic extracts contained a greater proportion of TRH in relation to the TRH-homologous peptides. Extracts of dog serum and semen were found to contain a TRH-binding substance which reduced the retention of added TRH by cation exchangers. The half-time of disappearance (t1/2) of synthetic TRH incubated at 23 degrees C in 10% (w/v) homogenates in 0.15 M-NaCl-0.05 M-phosphate buffer, pH 7.5, ranged from 22 +/- 10 (S.D.) min for liver to 120 +/- 58 min for thyroid. The short t1/2 for TRH added to dog liver homogenates contrasted with a previous report that dog liver is essentially free of TRH-degrading activity.

Inability of cytoplasmic or nuclear androgen receptor content or distribution to distinguish benign from carcinomatous human prostate

We used exchange saturation analysis at 15 degrees to quantitate total cytoplasmic and nuclear androgen receptor content of 70 patient specimens. Cytoplasmic androgen receptor contents (fmol/mg DNA) for eight specimens of clinically benign hyperplasia, 14 specimens of histologically hyperplastic prostate obtained at cystoprostatectomy, and carcinomatous and noncarcinomatous prostate obtained at radical prostatectomy for prostatic carcinoma, 48 specimens, respectively, were 830 +/- 165 (mean +/- S.E.), 890 +/- 445, 955 +/- 240, and 750 +/- 95. Nuclear androgen receptor contents of these same specimens, respectively, were 275 +/- 40, 235 +/- 30, 345 +/- 25, and 350 +/- 30; whereas, the values of the cytoplasmic/nuclear receptor content, respectively, were 3.25 +/- 0.55, 3.05 +/- 0.80, 2.50 +/- 0.50, and 2.80 +/- 0.40. Multiway analyses of variance of these cross-sectional data showed that there was no significant difference (p greater than 0.05) between group mean values. This result principally reflects the fact that the families of values for the four tissue groups were highly heterogenous with broad overlap. The results would not appear to be unduly influenced by carcinomatous epithelial cell content of the specimens, because cytoplasmic and nuclear androgen receptor content were not related to specimen carcinomatous epithelial cell content. Paired analyses of receptor content in carcinomatous and noncarcinomatous prostate specimens from the same prostate showed enhanced or unchanged receptor content in 58% (cytoplasmic) and 62% (nuclear) of specimens. Our studies show that cross-sectional analyses of androgen receptor content fail to distinguish carcinomatous prostate from noncarcinomatous prostate. However, paired analyses of these tissues from the same gland identify distinguishing differences. The clinical relevance of these observations remains to be examined.

Amino acid sequence homology between rat prostatic steroid binding protein and rabbit uteroglobin

Using a computer program designed to detect evolutionary relationships between proteins, I find that the polypeptide chain of rabbit uteroglobin has amino acid sequence homology with the C1 and C2 polypeptide chains of rat prostatic steroid binding protein. Using this finding I suggest several interesting approaches for studying the biology of these proteins.

Active immunization with follicle-stimulating hormone for fertility control: a 4 1/2-year study in male rhesus monkeys

Active immunization of four adult rhesus monkeys with highly purified ovine follicle-stimulating hormone (FSH) over 4 1/2 years resulted in the production of specific FSH antibodies. While luteinizing hormone and testosterone secretion were not affected, sperm counts were in most instances reduced to or below the lower normal range. On a few occasions, azoospermia or high sperm counts were observed. Although the antibodies produced neutralized the biologic activity of FSH throughout, spermatogenesis gradually returned, as evidenced by testicular histologic characteristics. However, the diameter of the seminiferous tubules remained decreased, and the germinal epithelium was depleted. No adverse side effects could be demonstrated in the immunized animals, e.g., immune complexes in either serum or tissues and resultant tissue damage. These results show that although active immunization with FSH may not result in an effective method of male fertility control, long-term immunization against a circulating hormone may not result in deleterious side effects.

Genital tract proteins in the male rabbit: I. Localization of uteroglobin

Uteroglobin synthesis in reproductive and non-reproductive tissues of male and female rabbit was screened by means of double-diffusion tests and immunohistochemical studies. Immunoprecipitates were observed when homogenates of male accessory were incubated with a monospecific antiserum against uteroglobin; in the female the antigen occurred in the uterine secretion and in homogenates of the oviduct, six days post coitum. In nonreproductive tissue, the antigen appeared both in the male and in the female, in the homogenate of trachea and lung. The immunofluorescence technique exhibited the paraprostate gland as the site of synthesis of uteroglobin in the male genital tract. Moreover, the distribution of the fluorescence within the cells was identical to the distribution observed in the female genital tract.

Factors affecting the reproducibility of androgen receptor determinations in human prostate

Several factors affecting the reproducibility of androgen receptor assays in the human prostate gland have been identified. Experiments in the presence of proteolytic inhibitors such as PMSF, leupeptin and aprotinin resulted in no change in the estimates of androgen receptors. The androgen binding was also unaffected by the concentrations of endogenous steroids in the tissue. Although the receptor assay was reliable down to protein concentrations of about 5 g/l, at lower concentrations the reliability of the method was significantly reduced. Similarly, tissue storage at -25 degrees C drastically lowered the binding capacity of the prostatic tissue extracts to 50% of initial receptor content over a period of 3 months. The high degree of correlation between receptor levels in the stroma and epithelium suggests that the binding in the total gland will not be drastically affected by the proportion of stroma and epithelium it contains. Following the widely practised 2-h extraction of the nucleus with 0.6 mol/l KCl buffer, a highly significant non-extractable binding component remained. Analysis of data by the single-point assay produced results comparable to those obtained by standard Scatchard analysis and seemed reliable so long as careful quality control was employed.

Isolation, properties, and androgen regulation of a 20-kilodalton protein from rat ventral prostate

An abundant 20-kilodalton protein has been isolated from the cytosol fraction of rat ventral prostate by ammonium sulfate precipitation, DNA-cellulose chromatography, and gel filtration. The purified 20K protein is a glycoprotein, containing 11% hexose by weight. It contains no fucose, hexosamine, or sialic acid. The 20K protein does not bind androgen. Binding of the 20K protein to DNA is nonspecific, showing affinity toward DNAs of various tissue origins, as well as poly(dA-dT), poly(rI-rC), and phosphocellulose. The 20K protein comprises about 9% of the total cytosolic proteins in rat ventral prostate. Examination of eight different rat organs, including prostate secretion, lateral and dorsal prostates, and rat ejaculate, for the presence of the 20K protein by double immunodiffusion analysis revealed that the protein is a rat ventral prostate specific secretory protein. Hybridization of prostatic poly(A) RNA with a cloned cDNA coding for the 20K protein indicated that the synthesis of the 20K protein is regulated by testosterone at the mRNA level.

Towards a reproducible method of estimating androgen receptors in human prostate

The effect of sodium molybdate and the stability of [3H]-R1881 on the reproducibility of androgen receptor assays in the human prostate gland have been investigated. The drying down of radio-labelled methyltrienolone, prior to incubation with cytosolic and nuclear extracts, resulted in a marked disintegration of the compound and a loss of specific binding of up to 40%. By contrast, the inclusion of sodium molybdate in the homogenisation buffer significantly increased the specific nuclear and cytosolic binding. In the cytosol, this increase was directly proportional to the amount of molybdate added up to 50 mM whereas in the nucleus binding was maximal at a molybdate concentration of 10 mM and declined at higher concentrations.

Protein characterization of multi-fraction split-ejaculates. Some physicochemical properties of prostatic and vesicular proteins

A simple method of splitting ejaculates into 10-15 consecutive fractions proved to be valuable for separating proteins of prostatic and vesicular origin. After blocking autoproteolysis by EDTA and PMSF the fractions of four multi-fraction split-ejaculates were studied by one-dimensional electrophoresis in the presence of SDS (slab SDS-PAGE). Two split-ejaculates were further analyzed by isoelectrofocusing (PAGIEF). The zinc and fructose distributions were determined for one of the samples. The results show i) that the initial third, roughly, of the ejaculate contains proteins previously characterized as of prostatic origin (Balerna et al., 1982 a); ii) that these initial fractions have a high zinc/fructose ratio; iii) that the vesicular portion of the ejaculate is characterized by low zinc/fructose ratio and by fairly high amounts of low molecular-weight proteins and; iiii) that the proteins of the initial (prostatic) part of the ejaculate are mainly acidic-neutral whereas some proteins of the final (vesicular part) have a strong cationic character.

[Studies on the androgen-binding proteins in human benign prostatic hypertrophy]

Androgen-binding proteins in the cytosol of human benign prostatic hypertrophic tissue were studied with 3H-dihydrotestosterone (DHT) and 3H-methyltrienolone (R 1881) as ligands. In the prostatic cytosol, saturable binding proteins with high affinity to 3H-DHT or 3H-R1881 were found by Scatchard analysis. The dissociation constant (Kd) for 3H-DHT was 9.4 X 10(-10)M, and the maximum number of binding sites (B max) was 55 fmoles/mg protein; the Kd for 3H-R1881 was 5.1 X 10(-9)M, and B max was 25.5 fmoles/mg protein. Competitive binding assay for each binding protein with various non-labeled steroids, demonstrated a specificity for DHT or R1881. The binding of prostatic cytosol and 3H-DHT was eluted by Sephadex G-200 column chromatography in 2 places, one in the void volume and one near the IgG fraction. The binding with 3H-R1881 was eluted in the void volume, the elution near the IgG fraction being very small, which suggests a non-specific binding. The binding of prostatic cytosol and 3H-DHT increased with increase in the concentration of Ca2+ or Mg2+ (0-12 mM), but the binding with 3H-R1881 decreased conversely. This change was studied with Sephadex G-200 column chromatography; the binding with 3H-DHT showed a decrease of the peak in the void volume and marked increase of the peak near the IgG fraction with increase in the concentration of both ions, whereas the binding with 3H-R1881 only showed a decrease of the peak in the void volume. Ca2+ had a greater influence than Mg2+ on the change of these bindings. These results indicate a change of binding protein due to ionic action, suggesting also the possibility of the presence of a substance in the cytosol which changes the properties of the binding protein dependent on Ca2+.

Nuclear androgen receptors of human prostatic tissue--a quantitative histological study

The objective of this study was to determine the nuclear dihydrotestosterone (DHT) nuclear receptors content in tissues of normal prostate, benign prostatic hypertrophy (BPH), and prostatic cancer. We also attempted to correlate this with the histological pattern of these tissues. Specimens were obtained from five normal subjects, 24 BPH, and 19 prostatic cancer patients. Nuclear receptors content was determined. All histological sections were reviewed by three independent pathologists. The criteria for the quantitative analysis were the degree of cellularity and the stromal content. The mean receptor content was not significantly different between neoplastic tissue (52.6 fmol/mg protein) and hyperplastic tissue (38.9 fmol/mg protein). The number of binding sites in normal prostatic tissue was 8.5 fmol/mg protein. The correlation between the degree of cellularity and DHT receptors showed no significant difference for both BPH, as well as prostatic cancer. Similar results were obtained when stromal content was compared.

The distribution of zinc in the prostate of rhesus and cynomolgus monkeys determined by electron microscopy and x-ray microanalysis

The distribution of zinc in the prostate of the mature rhesus monkey is described. High levels of zinc were located in the nuclei of epithelial and basal cells in both lobes of the gland, while elevated concentrations of the metal were also found in secretory granules and along lateral cell membranes. A similar zinc distribution pattern was observed in the 2 lobes of the gland, but in general organelles in the cranial region had a higher content of the metal. In whole tissue, however, a 15 times greater zinc content was measured in the caudal lobe. This difference could be explained in terms of the high levels of the metal present in secretory granules and luminal secretion in the caudal lobe. A similar ultrastructural appearance and distribution of zinc was observed in the prostate of the cynomolgus monkey (Macaca fascicularis).

Subcellular distribution of androgen receptors in human normal, benign hyperplastic, and malignant prostatic tissues: characterization of nuclear salt-resistant receptors

Two populations of nuclear androgen receptors have been characterized in human prostatic tissue, and the levels and proportions of each were found to differ in normal prostates, benign hyperplastic prostates (BPH), and malignant prostates. A significant percentage (35 to 50%) of total nuclear androgen receptors was associated with the salt-resistant nuclear matrix fraction. The remainder were easily extracted from nuclei by 0.6 M KCl. Optimal conditions for measuring receptors in both compartments involved the use of an inhibitor of proteolysis (phenylmethylsulfonyl fluoride) and the omission of dithiothreitol from buffers. In the presence of dithiothreitol, most of the nuclear salt-resistant receptors were rendered salt extractable. Cytosol androgen receptor levels were not significantly different in normal, BPH, or malignant prostatic tissues. In contrast, the levels and distribution of nuclear salt-extractable and salt-resistant androgen receptors exhibited characteristic patterns. Compared to normal prostatic tissue, nuclear salt-extractable receptors were significantly elevated in both BPH and cancer, whereas nuclear salt-resistant receptors were elevated in BPH but not in cancer. The ratio of salt-extractable to salt-resistant receptors was approximately 1:1 in both normal and BPH tissues and 2:1 in cancer. In addition, a microassay has been developed for the measurement of androgen receptors in the three subcellular compartments of needle biopsy specimens of prostatic cancer. Studies are in progress to determine whether the measurement of both nuclear salt-extractable and salt-resistant receptors may improve the usefulness of receptor levels to predict the hormonal responsiveness of prostatic cancer.

Androgen receptor in electroresected and cold punch-resected specimens. Usefulness of Kaplan cold punch resectoscope

The measurement of androgen receptor and 5 alpha-dihydrotestosterone (DHT) levels in prostatic carcinoma may be of value in predicting responsiveness to anti-androgenic therapy. A sufficient amount of prostatic carcinoma tissue must be removed for measuring androgen receptor and DHT levels. We have studied the usefulness of Kaplan cold punch-resection compared with electroresection for obtaining tissue in 29 cases of enucleated benign prostatic hyperplasia. DHT level in electroresected specimens was similar to controls. However, following low, moderate, and high-power electroresection an average of total R1881 binding sites (Bmax) of electroresected specimens was reduced to 82.2, 71.9, and 52.1 per cent of corresponding controls, respectively. In contrast, the per cent decrease of Bmax of Kaplan cold punch-resected specimens was only 10 per cent of the control. From our data, Kaplan cold punch-resection of the prostate appears to be a useful tool for obtaining tissue suitable for measuring androgen receptor levels.

Are fluorescein-conjugated androgens appropriate for a histochemical detection of prostatic androgen receptors?

Histochemical fluorescence techniques could be of great value in order to assay androgen receptors (AR), particularly in punch biopsies from human prostatic carcinoma (PCA). Therefore, prostatic tissue was examined for specific binding of fluorescein-labeled 5 alpha-dihydrotestosterone derivatives (FDHT) to AR. Using a 17 beta-fluoresceinated DHT derivative (17-FDHT), variable fluorescence was found in human and rat prostates at high 17-FDHT concentrations. This fluorescence could be blocked by unlabeled DHT in 11 and 73% of human and rat prostatic tissue, respectively. Control studies of receptor and organ specificity were conducted and showed that preheated slices from rat prostates displayed no decrease of fluorescent staining. No difference in fluorescence intensity could be seen between prostates from castrated and uncastrated rats. Unstained tissue slices frequently showed a considerable intensity of autofluorescence. An appreciable amount of fluorescence in both rat liver and spleen was found. From these results and various general methodical problems inherent in fluorescent receptor assays, we conclude that the fluorescence techniques described are inappropriate for demonstration of AR.

Androgen receptors in rat and human prostate

In intact adult rats almost all androgen receptor (AR) sites of the rat ventral prostate (RVP) are occupied by endogenous dihydrotestosterone, and about 80% of these sites are nuclear. Nuclear AR disappears rapidly after castration (half-life of 3 h). The amount of cytosolic AR does not change within the initial 36 h, then markedly decreases during the next 2-5 days. An early and specific action of androgen is a remarkable increase of its own receptor. RVP also contains an estradiol receptor (ER) which rapidly disappears after castration and which, contrary to AR, is predominantly localized in the cytosol of stromal elements. The published procedures for steroid receptors grossly underestimate receptors concentrations in normal (NHP) and hyperplastic (BPH) human prostate. We have recently established a reliable method for the measurement of total AR, and we have found no difference in AR concentrations between NHP and BPH. BPH also contains a progesterone receptor and an elusive ER. Finally, we have used specific immunoglobulins in sex hormone binding plasma protein (SBP) for the demonstration of SBP-like immunoreactivity by the indirect immunofluorescence technique. The specific antigenic material was exclusively localized in the cytoplasm of BPH epithelial cells.