Comparison of residual C-19 steroids in plasma and prostatic tissue of human, rat and guinea pig after castration: unique importance of extratesticular androgens in men

The concentrations of dehydroepiandrosterone (DHEA), its sulfate (DHEAS), androstenedione (A-dione), testosterone (T) and dihydrotestosterone (DHT) have been measured before and after castration in men and two animal models, namely the rat and the guinea pig. In adult men, the pre-castration levels of plasma DHEAS and DHEA were measured at 1839 +/- 320 and 2.4 +/- 0.5 ng/ml, respectively, while in both animal models, the concentrations of these two steroids were below 0.3 ng/ml. Orchiectomy in men reduced plasma T and DHT levels from 2.9 +/- 0.1 and 0.60 +/- 0.10 to 0.42 +/- 0.21 and 0.05 +/- 0.01 ng/ml (P less than 0.01), respectively, while there was no significant effect observed on DHEAS, DHEA and A-dione levels. By contrast, castration in the rat reduced the low levels of circulating DHEA and A-dione below the detection of the radioimmunoassay (RIA) used. In castrated guinea pig, a small quantity of plasma A-dione (0.07 +/- 0.02 ng/ml) was measured while DHEA was undetectable. Moreover, in the rat and guinea pig, plasma T and DHT levels became undetectable. Following administration of the antiandrogen Flutamide for two weeks in the castrated rat and guinea pig, prostate weight was not further reduced, thus indicating that there is no significant androgenic activity left following castration of these two species. In fact, castration in the rat and guinea pig caused a decrease in prostatic levels of DHT from 4.24 +/- 0.351 and 9.42 +/- 1.43 ng/g, respectively, to undetectable levels. In men, on the other hand, the prostatic DHT levels were only inhibited from 5.24 +/- 0.59 to 2.70 +/- 1.50 ng/g, respectively. As expected, when Flutamide was administered to the rat and the guinea pig, the levels of prostatic steroids remained undetectable while, in men, the DHT content in the prostate was further reduced to undetectable values. In summary, the plasma levels of DHEAS, DHEA, delta 4-dione are markedly different between men and both animal models used and furthermore, measurements of prostatic levels of androgens suggest that the high plasma levels of these steroids are likely responsible for the presence of important amounts of DHT in human prostate after castration.

Isolation and sequence of a cDNA clone of beta-nerve growth factor from the guinea pig prostate gland

The guinea pig prostate gland contains high levels of nerve growth factor similarly to the mouse submandibular gland. Nerve growth factor from the guinea pig prostate gland cross-reacts weakly with antisera directed against mouse nerve growth factor, is associated with different proteins, and may be processed by a different mechanism. We have isolated a full-length cDNA clone for nerve growth factor from a library prepared from RNA of the guinea pig prostate gland. The guinea pig cDNA contains 1,075 nucleotides and is very similar to the shorter of two predominant nerve growth factor transcripts present in the mouse submandibular gland. The cDNA sequence predicts a precursor protein of 241 amino acids that is 86% identical to the mouse amino acid sequence. Only 10 amino acid changes are present in the C-terminal region corresponding to the mature 118 amino acid beta-nerve growth factor of the mouse. Dibasic amino acid processing sites that are present at the N- and C-termini of the mature protein sequence and two other dibasic amino acid sites, representing potential processing sites within the propeptide, are all conserved, suggesting a similar mechanism of processing.

[Histologic hormone studies, a practical evaluation]

Based on histological studies of the prostate or Bartholin's gland, chemical analysis of the urine, injection site or implant was conducted in 114 veal calves suspected of receiving hormonal treatment. In 65% of the samples the results of chemical analysis confirmed the histological findings.

Microassay for prostatic androgen receptors correlated with quantitative histological assessment

A new microassay in which cryostat sections of prostate tissue were used to provide the source of soluble androgen receptor for biochemical assay, was devised using an isoelectric focusing method, with [3H]-mibolerone as the androgenic radioligand. Adjacent cryostat sections from the same tissue block were stained for diagnostic and quantitative histological assessment. The assay was used to illustrate variations in tissue androgen receptor concentration for correlation with epithelial cell content in benign prostate hyperplasia and prostatic cancer, and to show the effects of androgen receptor concentration of resection of prostatic tissue by electroresection. The results indicate that the heat in electroresection renders prostatic tissue unsuitable for androgen receptor assays, and suggest that knowledge of the cellular composition of carcinomatous prostates may be of importance in the full assessment of androgen receptor assay results. This method incorporates both a biochemical assay and histological assessment of the assayed tissue on near-facsimile sections, an advantage over conventional biochemical assays.

[Pepsinogen C in the human prostate]

The authors investigated the proteolytic activity of the normal prostate, the prostate with benign hypertrophy and with cancer. Pepsinogen obtained from the normal prostate was isolated on DEAHP pearl cellulose and purified by means of affinite chromatography. Separation on affinite chromatography and by electrophoresis on agar confirmed that the pepsinogen is identical with gastric progastricsin. The proteolytic activity was examined by a modified method of Anson and Mirsky, and with the aid of synthetic substrates it was assessed quantitatively in all three examined groups. The enzyme activity of the carcinomatous tissue practically did not differ from the activity of the normal prostate. In beniming hypertrophy of the prostate the proteolytic activity assessed by the breakdown of haemoglobin is markedly reduced and when tested on the breakdown of synthetic substrates [For-Tyr-Tyr- and Ac-Phe- Tyr (I2)] it is practically zero.

Three-month treatment with a long-acting gonadotropin-releasing hormone agonist of patients with benign prostatic hyperplasia: effects on tissue androgen concentration, 5 alpha-reductase activity and androgen receptor content

The intraprostatic concentrations of testosterone (T) and dihydrotestosterone (DHT) have been measured in only a few men. We measured, in prostatic tissue obtained at surgery from seven men with benign prostatic hyperplasia, the effects of 3-month treatment with a long-acting GnRH agonist on 1) the intraprostatic concentrations of T, DHT, and 5 alpha-androstan-3 alpha, 17 beta-diol (3 alpha-diol); 2) prostatic 5 alpha-reductase activity; and 3) the prostatic content of androgen receptors (AR). Plasma T, DHT, and 3 alpha-diol levels also were measured. Prostatic tissue samples obtained at surgery from a group of untreated men with benign prostatic hyperplasia also were studied. The mean DHT and 3 alpha-diol concentrations in the prostatic tissue of the treated men were about 10% of those in untreated men (n = 19; P less than 0.01 for DHT and P less than 0.05 for 3 alpha-diol), and the mean intraprostatic T concentration in the treated men was about 25% of that in the control group (0.10 greater than P greater than 0.05). The mean in vitro formation of DHT by the prostatic tissue of the treated men was about 50% lower (P less than 0.05) than that by prostatic tissue of the untreated men (n = 9). The mean cytosolic AR content in the prostatic tissue of the treated men was significantly higher (P less than 0.05), whereas the mean nuclear content of both salt-extractable and salt-resistant AR was significantly lower (P less than 0.05) than that in the prostatic tissue of the untreated men (n = 8). The mean plasma T levels in treated men decreased from 4.77 +/- 1.79 (SD) ng/mL (16.5 +/- 6.2 nmol/L) to 0.27 +/- 0.42 ng/mL (0.9 +/- 1.5 nmol/L) after 1 month of therapy and remained in the castrate range thereafter. We conclude that pharmacological castration resulting from 3-month treatment with a long-acting GnRH agonist decreases the intraprostatic T concentration to about one fourth and those of DHT and 3 alpha-diol to about one tenth of the levels in untreated men. Thus, GnRH agonist treatment may not completely abolish intraprostatic androgen concentrations in metastatic prostatic cancer patients. The decrease in prostatic 5 alpha-reductase activity as well as the decrease in nuclear receptors are probably secondary to the decrease in plasma T concentrations.

Expression of three forms of thyroid hormone receptor in human tissues

At least two thyroid hormone receptor (hTR) genes are present in humans, but the significance of this multiplicity is unknown. These receptors could have differences in tissue distribution or possess different functions. We studied the distribution and abundance of three hTR mRNAs (hTR beta, hTR alpha 1, and hTR alpha 2) by Northern blot analysis. Three mRNAs were expressed in all tissues examined. hTR beta was strongly expressed in brain and prostate predominantly as a 10.0-kilobase (kb) mRNA. This mRNA was also expressed in thyroid and was much less abundant in liver, kidney, placenta, tonsil, and spleen. hTR alpha 1 is represented by two mRNAs with sizes of 6.0 and 3.2 kb. The 6.0-kb mRNA was constantly less abundant than the 3.2-kb mRNA. hTR alpha 2 was detected as a single mRNA with a size of 3.2 kb, using a probe unique for this mRNA. Both hTR alpha 1 and hTR alpha 2 were strongly expressed in brain, prostate, and thyroid and much less in other tissues. The relative amounts of the three hTR mRNAs were roughly parallel in each tissue. It is of interest that none of these hTRs was abundant in liver, which is the major thyroid hormone-responsive organ. Another hTR may be present in liver.

Pathogenesis and medical treatment of benign prostatic hyperplasia

Tissue concentrations of dihydrotestosterone (DHT) and the enzymes that regulate its level, such as 5 alpha-reductase, appear to play a major role in the pathogenesis of benign prostatic hyperplasia (BPH). This argument is strongly supported by the objective decreases in prostate size and improvement in symptoms of prostatism that occur following androgen withdrawal. A variety of androgen-withdrawal therapies for BPH have been reported since the early 1900s. Although success in the treatment of BPH has been claimed for all of them, including surgical castration, medical castration with progestational antiandrogens, gonadotropin-releasing hormone (GNRH)-agonist castration, or androgen-receptor blockade with pure antiandrogens such as flutamide, very few studies, until recently, have provided convincing objective evidence for therapeutic efficacy in BPH. Recently, magnetic resonance imaging (MRI) scanning and ultrasound have become available to quantify objective changes in prostate volume and have indisputably demonstrated that androgen withdrawal does significantly decrease prostate size. The consequences of this on clinical symptoms of prostatism are currently under study. Studies of the effect of 5 alpha-reductase inhibitors on prostatism are in progress. They hold promise for future treatment of BPH since they may decrease prostate size and DHT concentration without any effect on sexual function.

Neural and glandular localisation of substance P in Echinostoma caproni (Trematoda-Digenea)

Immunocytochemical studies using antibodies against various peptides were performed on Echinostoma caproni. Only the presence of substance P or a related peptide was clearly demonstrated in this digenetic trematode. In the central nervous system, substance P-immunoreactive neurons were few and constituted two populations according to their size. Labelled axons were observed in the ventral and dorsal nerve cords. Scarce, small neurons and fibres were detected in the peripheral nervous system. The comparative study of 6- and 14-day-old worms showed an overall increase in substance P-immunoreactive nerve structures in the latter. Strong immunoreactivity for substance P was found in prostate cells from 14-day-old worms, whereas none was observed in 6-day-old worms. Thus, positive immunoreactivity seemed to be related to sexual maturity.

Ultrastructural localization of proteoglycans by cationic dyes in the epithelial-stromal interface of the guinea pig lateral prostate

Proteoglycans (PGs) in the epithelial-stromal interface of the guinea pig lateral prostate were localized at ultrastructural level, using cuprolinic Blue (CB), alcian Blue (AB), and ruthenium red (RR). After staining with CB or AB according to the critical electrolyte concentration method (CEC), PGs appeared as short electron-dense filaments. According to their sizes and location, three type (T1, T2, T3) of CB-stained filaments were identified. T1 filaments were short (25 nm) and were found on both sides of the lamina densa of the basal laminae of the prostatic epithelium, smooth muscle cells, and capillary endothelial cells. They were regularly spaced with an interval of 60 nm. T1 filaments were more randomly distributed in the lamina densa. T2 CB filaments were approximately 30-40 nm long and closely associated with the collagen fibrils. They were usually arranged perpendicular to the long axis of collagen fibrils also at intervals of 60 nm. T3 filaments were found in different regions of the lamina propria, including: 1) reticular layer (pars fibroreticularis) below the basal lamina; 2) interstitial spaces; 3) closely associated with the cell surfaces of fibroblasts; and 4) around the collagen fibrils. Their sizes were variable (60-100 nm) and more densely stained. AB revealed similar patterns of PG distribution, except that the three types of PG filaments were longer but thinner. When the tissues were stained with RR, or RR-AB combined, PGs appeared as dense granules of various sizes, instead of filaments. Their locations and distributions were similar to those of the CB filaments, except that in the case of combined RR-AB treatment the PG granules were linked by a fine filamentous network, suggesting the interconnecting nature of the PGs and other extracellular components.

Localization of the PRR1 gene coding for rat prostatic proline-rich polypeptides to chromosome 10 by in situ hybridization

The gene coding for rat ventral prostatic proline-rich polypeptides (PRR1) was mapped to chromosome region 10q26----q31 by in situ hybridization. The high percentage (40%) of specific hybridization signal obtained is probably the result of the highly repetitive structure of the PRR1 gene.

[Enoxacin concentration in seminal fluid, in prostate secretions and in prostatic adenoma tissue following oral administration or intravenous infusion]

In eleven volunteers and 39 patients undergoing transurethral resection of the prostate or bladder tumor, concentrations of enoxacin were measured in seminal fluid (volunteers), in prostatic fluid (volunteers, patients) and in prostatic adenoma tissue (patients) after oral (400 mg) administration and intravenous (428 mg) infusion (60 min) of enoxacin. Simultaneously 2.534 g of iothalamic acid was i.v. injected to identify possible urinary contamination. The concentrations of enoxacin in seminal fluid after 2-4 h and in prostatic tissue after about 1-4 h and 14-16 h exceeded plasma concentrations more than two-fold. The concentrations in prostatic fluid after 1-4 h were about half the plasma concentrations. Venous blood samples were taken after intravenous infusion at intervals of up to 24 h in a total of 14 patients. The mean plasma concentration of enoxacin decreased from its maximum of 6.9 mg/l at the end of infusion to 0.5 mg/l at 12 h after administration. A terminal half life of 6.65 h was calculated according to an open two-compartment model.

Immunohistochemical localization of laminin in the basement membranes of normal, hyperplastic, and neoplastic human prostate

We examined the effects of fixatives and antibody sources on the immunohistologic localization of laminin in normal and cancer-containing human prostates and studied the localization patterns in carcinomas of varying degrees of histologic differentiation. Two different polyclonal antibodies were localized in paraffin-embedded or cryostat sections of fixed (alcohol, formalin, and paraformaldehyde) or unfixed tissue, using the immunofluorescence (IF) or immunoperoxidase (IP) techniques, with positive and negative controls. We found that the IF reactions were more intense in unfixed or alcohol-fixed sections than in paraformaldehyde-fixed specimens. IP reactions were very weak or absent in fixed and paraffin-embedded sections, but pepsin treatment of these sections resulted in more intense and uniform IP reaction products, stronger than in unfixed or ethanol-fixed cryostat sections. With the IP technique, laminin localization was intense and uniform in the basement membranes (BM) of acini, blood vessels, smooth muscle, and nerve fibers in normal prostate, benign hyperplasia (BPH), and well-differentiated carcinomas. The BM of poorly differentiated carcinomas showed widespread absence of laminin reactivity. In normal BPH and well-differentiated tumors, occasional epithelial cells and their surface and acinar lumina had laminin reactivity. However, in higher grade tumors, numerous neoplastic cells had laminin reactivity in cytoplasm, their surface, and secretory material. Some macrophages and neutrophils also contained laminin reactivity, presumably of degraded laminin. In some moderately and poorly differentiated tumors, the BM of small capillaries did not contain laminin. The BM of larger vessels always had laminin reactivity, even in the higher grade tumors.

Cytochemical characterization of cuprolinic blue-stained proteoglycans in the epithelial-stromal interface of the guinea pig lateral prostate

Three types (T1, T2, T3) of proteoglycan (PG) filaments, as demonstrated by cuprolinic blue (CB) under critical electrolyte concentration method in the epithelial-stromal interface of the guinea pig lateral prostate, were characterized cytochemically by using a number of glycosaminoglycan(GAG)-degrading enzymes and nitrous acid. The results showed that T1 filaments located in basement membranes of the epithelium, endothelium, and smooth muscle cells, were removed by nitrous acid, heparitinase, and pronase but resistant to chondroitinase (Ch)-ABC and Ch-AC, heparinase, neuraminidase, and Streptomyces (S) hyaluronidase. The T1 filaments, therefore, contain heparan sulfate. The T2 filaments closely linked to collagen fibrils were removed by Ch-ABC, Ch-ABC plus S-hyaluronidase, and pronase but were resistant to nitrous acid, heparitinase, heparinase, neuraminidase, and S-hyaluronidase. These show that T2 filaments are rich in dermatan sulfate. The T3 filaments in the interstitial spaces and on the surface of fibroblasts were removed by Ch-ABC, Ch-AC, and pronase but were resistant to heparitinase, heparinase, hyaluronidase, neuraminidase, and nitrous acid. They are, therefore, rich in chondroitin sulfate.

Unoccupied prolactin binding components of the benign and malignant human prostate in a subclinical and clinical procedure

Optimal conditions for the quantitation of free prolactin binding components of human prostatic tissue obtained by TURP were studied by applying gamma receptor assay. The radioligand used was 125I-prolactin. Significantly greater heat stability of the prostate membrane prolactin binding sites, when compared to that of androgen cytoplasmic receptors, was confirmed. The saturability and specificity of the prolactin binding components was demonstrated by the results of both Scatchard plot analysis and displacement studies. Free prolactin receptors were found in none of the poorly differentiated (G3) prostatic tumors examined, and only in 62.5% of medium differentiated (G2) prostatic malignancies. The majority of tissue specimens coming from patients with either BPH or well differentiated prostatic tumor (G1) contain measureable amounts of free prolactin membrane binding components. In the present study we report also the case in which the change in tumor differentiation toward a higher grade (G2 to G1, provoked by the successful chemohormonal treatment) is accompanied with the appearance of previously absent free prolactin binding components. In histologically proven BPH tissue specimens free prolactin receptor negative status has been found in most patients with a slight increase in serum PAP values, while receptor rich status was detected in the majority of those with elevated PSA concentrations. We believe therefore that the prolactin receptor values, when used as part of the multivariable analysis, may participate in further delineation of the role of prolactin in the development of prostate cancer, but may also play a role in a subclinical prediction related to the conversion of either an adenoma or a latent adenocarcinoma to the clinically manifest prostatic malignancy.

Partial characterization of a thyroid-stimulating hormone-like peptide in neuroendocrine cells of the human prostate gland

Immunohistochemical identification of the most prevalent type of neuroendocrine (NE) cells in the human prostate gland can be made with polyclonal antisera against human thyroid-stimulating hormone (TSH). A TSH-like peptide was characterized by analysis of prostatic tissue homogenates with sodium dodecyl sulfate-polyacrylamide gel (SDS-PAGE) electrophoresis followed by immunoblotting. A single protein band, with an apparent mass of about 32 kDa after reduction, was identified both with polyclonal antisera against human TSH and with a polyclonal antiserum raised against a synthetic peptide corresponding to the carboxyterminal part of the beta-subunit of human TSH. The TSH-like prostatic peptide identified here is, on the basis of its molecular mass and absence of immunoreactivity with an antiserum raised against a synthetic peptide representing the mid-portion of the beta-subunit of TSH, not identical with the pituitary beta-subunit of TSH. On the other hand, this 32 kDa prostatic peptide may have certain structural elements in common with the pituitary beta-subunit of TSH, since it is recognized both with polyclonal antisera against TSH and with an antiserum against the carboxyterminal part of the beta-subunit of TSH.

Nuclear DNA analysis of prostate tissues: correlation with stage and grade of tumour

Flow cytometry was used to analyse the DNA content of 20 unfixed prostatic specimens obtained from patients with cancer of the prostate. The tumours were of different stages and grades of differentiation and the numbers of cells in each phase of the cell cycle were compared to those obtained from 26 patients with benign prostatic hyperplasia. It was noted that, as the cancer progressed from a well to a poorly differentiated state, there was a distinct shift in the distribution of cells in the G0/G1 phase towards the S and G2+M phases. This was particularly marked in cases with a summed Gleason score of 7-10, and was independent of the stage and bulk of the tumour. Furthermore, all tumours with a Gleason score of 7 or more exhibited a tetraploid histogram, whereas only 2 of 14 patients with a well or moderately well differentiated cancer had tetraploid histograms. Two patients were found to have tumours with aneuploid DNA content, and both died within 2 years from the time of diagnosis. Although it is too early to speculate on the place flow cytometry in the clinical management of patients with cancer of the prostate, the results generated from this present study suggest that flow cytometry may be capable of providing prognostic information not supplied from histopathological analysis.

Intracellular distribution of calcium and zinc in normal, hyperplastic, and neoplastic human prostate: X-ray microanalysis of freeze-dried cryosections

X-ray microanalysis has been performed on freeze-dried cryosections of normal, hyperplastic, and neoplastic human prostates. Needle biopsies from prostates suspected to be malignant were collected from ten patients. Seven of these patients had fully developed nodular hyperplasia, whereas the remaining three specimens were histologically classified as moderately differentiated adenocarcinomas. Prostates with normal light microscopic appearance were obtained from two brain-dead kidney donors. The concentration of calcium in secretory vesicles was found to be several orders of magnitude higher than the concentration of magnesium and zinc in all of the glands studied, which is consistent with calcium being the major cation secreted by the prostatic acinar cells. Some elderly prostates and neoplastic prostates revealed even lower mean zinc:calcium ratios in secretory vesicles. Even though both elements varied considerably, the wide variation of the zinc:calcium ratios was due mainly to variations in the concentration of zinc. Large, electron-dense bodies occasionally were found in the cytoplasm of prostatic acinar cells. These bodies contained high concentrations of sulphur which by far was the dominating element.

Effect of treatment on the expression of estramustine-binding protein (EMBP) in prostatic cancer patients: an immunohistochemical study

Estramustine-binding protein (EMBP) was determined immunohistochemically in prostatic cancer (PC) specimens taken from patients before and after therapy. The EMBP staining intensity was correlated with the tumor malignancy grade in untreated PCs. The effect of various treatments (i.e., androgen-withdrawal therapy, treatment with estramustine phosphate or radiation) on the expression of EMBP was also investigated. Although a rabbit polyclonal antiserum raised against rat EMBP was used all through the study, all untreated PCs (n = 53) examined so far displayed a positive immunoreaction. The staining intensity was higher in moderately and poorly differentiated than in well-differentiated tumors. Furthermore, two types of staining patterns were observed, that is, a diffuse type in about 70% and a focal in the remaining cases, which might reflect the multifocal appearance of PCs. The prognostic significance of these staining patterns is discussed. Irrespective of the treatment used, EMBP staining was reduced to lower or undetectable levels in PCs where cytological as well as clinical regression were indicated after 6-30 months of therapy. In nonresponders or patients with refractory disease, however, EMBP expression reappeared and returned to pretreatment levels. In a short-term follow-up, the diminuation of EMBP was evident as early as 10 days after androgen-withdrawal therapy and persisted as long as the patient responded to therapy. When estramustine phosphate was given as secondary treatment to hormone refractory PCs, EMBP decreased to undetectable levels in 3/4 of the specimens, suggesting response to therapy. In conclusion, a decreased EMBP staining was well correlated with favorable cytological regression as well as with clinical regression, whereas unchanged staining intensity was indicative of clinical progression and a poor cytological regression grade. The high levels of EMBP in moderately and poorly differentiated tumors as well as in relapsing PCs, despite continued androgen withdrawal, strongly support a regulation of EMBP that is not under androgenic control. Based on the present findings, we suggest the use of EMBP as a therapy marker. Provided that immunohistochemical measurements can be performed on fine-needle aspirates, EMBP analysis may be a direct and early means to distinguish between responding patients and nonresponders.

Looking for human glandular kallikrein-1 in the prostate

Based on recent studies indicating that human glandular kallikrein-1 (hGK-1) mRNA was present in the prostate, we have undertaken to determine whether the prostate contained trypsin-like proteases with properties compatible with those deduced from hGK-1 gene nucleotide sequence. The first series of experiments showed that only minimal levels of trypsin-like enzymatic activity, determined with synthetic substrates, were present in chromatographic fractions of prostatic glycoproteins having a molecular weight in the range expected for hGK-1, i.e., 25,000-35,000. Because of this, we used [3H]diisopropylfluorophosphate (DFP) labeling alone or in the presence of various serine-protease inhibitors to identify trypsin-like proteases in the prostate. Two-dimensional gel electrophoresis of prostatic glycoproteins showed the presence of minor spots of 18-32 kDa. These spots were slightly more acidic than were those of prostate specific antigen (PSA) and were completely inhibited by preincubation with tosyl lysine chloromethyl ketone and p-nitrophenyl-p-guanidobenzoate in contrast to PSA spots that were not affected by these treatments. When a similar procedure was applied to total cytosolic proteins instead of glycoproteins, an additional 30 kDa DFP binding protein was observed. This relatively abundant protein was much more acidic than was PSA and was not inhibited by any of the protease inhibitors tested. In conclusion, this study has permitted us to demonstrate the presence of two sets of proteins that have physicochemical properties compatible with those that can be deduced from the information contained in the hGK-1 gene.

Identification of an androgen-repressed mRNA in rat ventral prostate as coding for sulphated glycoprotein 2 by cDNA cloning and sequence analysis

The concentrations of a small number of mRNAs in the rat ventral prostate increase after castration and then decrease upon androgen treatment. Since the repression of specific gene expression may be important in the regulation of organ growth, we have cloned a cDNA for an androgen-repressed mRNA, the concentration of which increased 17-fold 4 days after castration, and this increase was reversed rapidly by androgen treatment. By sequence analysis the androgen-repressed mRNA was identified as that coding for sulphated glycoprotein 2.

Numbers and heterogeneity of mast cells in the male genital tract of the rat

Normal adult rats were used to quantitate and characterize mast cells in the male genital tract. The tissues were either fixed in a fixative containing formalin (Schaffer solution) or with basic lead acetate (BLA) to identify 'connective-tissue mast cells' and 'mucosal mast cells', respectively. In the epididymis and seminal vesicle small numbers of mast cells were identified without any obvious heterogeneity. In the prostate, however, a mean of 45.1 +/- 9.3 and 23.0 +/- 4.0 mast cells/mm2 was found after BLA and Schaffer fixation, respectively. This difference might be of functional and clinical significance.

Immunocytochemical localization and lectin-binding properties of the 22 kDa secretory protein from rat ventral prostate

The distribution of the 22 kDa secretory protein from rat ventral prostate was studied by light and electron microscopic immunocytochemistry. An anti-22 kDa protein antiserum was raised in rabbits and its specificity was tested by Western blotting. With the immunofluorescence technique, the 22 kDa protein was detected in the luminal secretions and intracellular apical granules of the ventral prostate. No reaction was observed in the seminal vesicle or dorsolateral prostate. After castration, no intracellular immunoreactivity was detected in ventral prostate, although positively labeled secretory material was retained within the acinar lumen. Restoration of normal intracellular staining pattern was incomplete after 5 daily testosterone injections. At the ultrastructural level, labeling was confined to apical secretory granules and condensing vacuoles. The 22 kDa protein separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transferred to nitrocellulose was shown to bind intensely to wheat germ agglutinin (WGA) but only faintly to Concanavalin A. This protein was thus demonstrated to contain N-acetylglucosamine residues. Accordingly, on tissue sections, WGA reacted intensely with condensing vacuoles and secretory granules.