Age-related changes in the innervation of the prostate gland

The adult prostate gland grows and develops under hormonal control while its physiological functions are controlled by the autonomic nervous system. The prostate gland receives sympathetic input via the hypogastric nerve and parasympathetic input via the pelvic nerve. In addition, the hypogastric and pelvic nerves also provide sensory inputs to the gland. This review provides a summary of the innervation of the adult prostate gland and describes the changes which occur with age and disease. Growth and development of the prostate gland is age dependent as is the occurrence of both benign prostate disease and prostate cancer. In parallel, the activity and influence of both the sympathetic and parasympathetic nervous system changes with age. The influence of the sympathetic nervous system on benign prostatic hyperplasia is well documented and this review considers the possibility of a link between changes in autonomic innervation and prostate cancer progression.     

Biochemical characterization and substrate specificity of rat prostate kallikrein (S3): comparison with tissue kallikrein, tonin and T-kininogenase.

A tissue kallikrein-like enzyme encoded by S3 mRNA was purified to homogeneity from rat prostate gland. The apparent molecular mass of the prostate enzyme is 32 kDa as determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The intact 32 kDa enzyme is split into two bands of lower molecular mass, 18 and 14 kDa, under reducing conditions on SDS-PAGE. NH2-terminal amino acid sequence analyses of the intact enzyme and heavy and light chains revealed the identity to the translated sequence of a prostate kallikrein cDNA (S3). Isoelectric focusing indicated that the prostate enzyme is a basic protein with pI of 7.30-7.45. Specific activities of the prostate kallikrein toward angiotensin I, angiotensinogen and rat low M(r) kininogen as well as tripeptide chromogenic substrates were compared with those of tissue kallikrein, tonin and T-kininogenase. The kinin-releasing activity is inhibited by leupeptin, antipain, benzamidine and soybean trypsin inhibitor. A sensitive and specific radioimmunoassay for the rat prostate kallikrein shows that the immunoreactive kallikrein levels in prostate and submandibular gland were 23.78 +/- 2.62 micrograms/mg protein (n = 5) and 12.29 +/- 2.25 micrograms/mg protein (n = 5), respectively. The results indicate that the prostate kallikrein S3 is expressed at high levels in both prostate and submandibular glands.     

The distribution of 5 alpha-reductase and 3 alpha(beta)-hydroxysteroid dehydrogenase activities in the hyperplastic human prostate gland

This study examines the distribution of 5 alpha-reductase and 3 alpha(beta)-hydroxysteroid dehydrogenase activities throughout the intact hyperplastic prostate gland and relate these measurements to the fibromuscular/epithelial composition and to the gross glandular morphology. The relative capacities of the stroma and epithelium to metabolize testosterone and dihydrotestosterone were also examined. The results indicate that under optimum reaction conditions an uneven distribution of 5 alpha-reductase and 3 alpha(beta)-hydroxysteroid dehydrogenase could be measured across the prostate. These regional variations reflect true differences in metabolic activity and were independent of any morphological changes: caution is therefore advised when interpreting hormonal metabolic data obtained from single sampling of the gland. Our investigations also suggest that the capacity to metabolize testosterone was evenly distributed between stroma and epithelium and that both tissue components are primary sites for 5 alpha-reductase activity. The reductive 3 alpha(beta)-hydroxysteroid dehydrogenase was also found in both tissue types but the mean stromal activity was marginally higher than the levels measured in the epithelium.     

Proteolytic modification of rat prolactin by subcellular fractions of the lactating rat mammary gland

The current study explored prolactin proteolysis by rat lactating mammary gland. 125I-labelled rat prolactin was incubated with tissue fractions of lactating mammary gland and the extent of prolactin degradation and fragment formation was visualized and densitometrically quantitated from autoradiographs derived from SDS-polyacrylamide gel electrophoresis under reducing conditions. At pH 4.5, the 25 000 X g pellet of mammary gland converted intact prolactin (23 kDa band) to proteolytic fragments (8-16 kDa bands) in a time- and tissue concentration-dependent fashion similar to that reported previously for rat ventral prostate. The prolactin-degrading and -fragmenting activity in lactating mammary gland was 5-10-times that observed for ventral prostate, the most active male tissue. This activity at acid pH was also demonstrable in other fractions of mammary gland but appeared to predominate in the cytosol. The above activities in mammary gland virtually disappeared at pH 7.4, appeared sensitive to aspartate and sulfhydryl proteinase inhibitors, and insensitive to serine and metalloenzyme proteinase inhibitors. The distribution of this activity could not be correlated with a particular enzyme marker. These characteristics of mammary gland activity differed significantly from those reported previously for prostate. When electrophoresis was conducted under non-reducing conditions, prolactin proteolysis in prostate and mammary gland was primarily associated with the formation of a more slowly migrating product (24 kDa band) with little spontaneous 8-16 kDa fragment formation. Re-electrophoresis of the 24 kDa band under reducing conditions resulted in the appearance of the 8 and 16 kDa fragments. In conclusion, prolactin is proteolytically modified by prostate and lactating mammary gland to a variant of intact hormone (24 kDa band) with a cleavage site in its large loop, by two or more widely distributed, acid-dependent proteinases. Lactating mammary gland, the principal target for prolactin, has the capacity to cleave the hormone in its loop at rates higher than any other tissue examined to date.     

Structural changes of the guinea pig prostatic epithelial cells after gossypol treatment

The effect of gossypol acetic acid on the prostate gland of the guinea pig was assessed ultrastructurally. The three lobes of the gland showed differences in sensitivity and reacted differently to gossypol treatment. In the lateral prostate, there was a reduction in the profile of the granular endoplasmic reticulum and dense secretory granules with a concurrent appearance of smaller clear granules and an increase in cytoplasmic filamentous bundles. The latter feature was similar to that of the coagulating gland. In the dorsal prostate, the general reaction was similar to that in the lateral prostate except that there was no increase in filamentous content. In the coagulating gland, there was a reduction or total disappearance of apical secretory blebs and an increase in lysosomes, a feature not found in the lateral and dorsal lobes. Damages to mitochondria were observed in the dorsal prostate and coagulating gland but not in the lateral prostate. It is concluded that gossypol affects not only the testis, but also alters the structure and functions of the prostate gland.     

A histochemical study of the secretions of reproductive glands and of the egg envelopes of Achatina fulica (Pulmonata: Stylommatophora)

Histochemical investigations of the secretions of reproductive glands—albumen gland, apical uterus, basal uterus and prostate gland—indicate the presence of galactogen in the albumen gland, acid mucopolysaccharide in the apical uterus, and lipoprotein in the basal uterus and prostate gland of A. fulica. The proteinaceous secretions produced by the glands do differ in their terminal reactive sites. Intense alkaline phosphatase reaction is found in albumen gland and apical uterus; carbonic anhydrase activity could be detected mainly in the uterine glands. The cyclical secretory activity of the reproductive glands has been studied preparatory to egg-laying and in the spent phase. Histochemical characteristics of the egg envelopes—albumen, shell membrane and egg-shell—suggest a possible sequential deposition of glandular products during the descent of eggs through the repv. ductive tract. The factors contributing to the stability and resistant nature of the egg envelopes, and the possible role of nutritive materials contained in reproductive gland secretions in the development of the embryo (even while the eggs are inside the uterus), are discussed.     

Metalloproteinase activities expressed during development and maturation of the rat prostatic complex and seminal vesicles.

The objective of this study was to characterize proteinase activities expressed during development and maturation of the prostate gland and seminal vesicles of the rat by using gelatin-and casein-containing SDS polyacrylamide gel zymography. The prostatic complexes of 2- and 10-day-old animals and the individual lobes of the prostate (ventral, dorsolateral, and anterior [coagulating gland]) and the seminal vesicles of 15-day-old animals expressed prominent gelatinolytic activities of approximately 64, 71, and 76 kDa. These activities had properties of metalloproteinases; i.e., they were stimulated by Ca2+ and inhibited by EDTA and EGTA. They were greatly diminished by 52 days of age (immediately postpuberty) and were not detected in the dorsal lobe of the adult. Less active gelatinolytic proteinases with molecular masses of approximately 34 and 43 kDa were expressed in the developing prostatic complexes and individual lobes and seminal vesicles, but they were not detected in postpubertal animals. Weak gelatinolytic activities of 82, 85, and 89 kDa were found in the prostatic complexes; these activities were greatly diminished in all prostate lobes with sexual maturation but were expressed in the seminal vesicles at all ages. A large-molecular-mass Ca(2+)-independent proteinase of 130 kDa or greater was first detected in the dorsolateral prostate at 21 days of age. This activity was expressed in both the lateral and dorsal lobes of the adult but was greater in the lateral lobe. Proteinase activities of about 22 and 26 kDa that were not stimulated by Ca2+ were detected in the ventral prostate at 15 days of age by means of both gelatin and casein gels.(ABSTRACT TRUNCATED AT 250 WORDS)     

Production and exocrine secretion of LHRH-like material by the male rat reproductive tract

Luteinizing hormone-releasing hormone (LHRH)-like immunoreactivity was localized in the male reproductive system of the rat. Epithelial cells of the epididymus, seminal vesicles and coagulation gland showed a strong reaction to anti-LHRH serum. Also the epithelia of the ductus deferens and the prostate gland appeared to be immunoreactive, albeit to a lesser extent. The LHRH-like substances are most likely secreted into the male tract, as can be concluded from the observation that the secretion product in the lumina of the seminal vesicles, coagulation gland and prostate gland was also immunopositive. The functional significance of these phenomena is discussed. No immunostaining was obtained with antisera to FSH, LH or beta-hCG.     

Murine mammary gland RNA directed synthesis of casein in a heterologous cell-free protein synthesis system.

A cell-free protein synthesis system derived from Ehrlich ascites tumor cell ribosomes (S30) plus rabbit reticulocyte tRNA was developed and the activity of the system was dependent on rabbit reticulocyte ribosomal salt (0.5 M KC1) wash factors, The exogenous mRNAs from BALB/c mouse liver and the mammary gland were translated with a high efficiency in this heterologous cell-free system. Furthermore, the RNA from the lactating mammary gland faithfully directed the synthesis of casein. The presence of mouse casein in the reaction product was identified by radioimmunoprecipitation with mouse casein antiserum, co-electrophoresis of the reaction product and mouse casein the urea-polyacrylamide gel and by electrophoresis in sodium dodecyl sulfate (SDS) polyacrylamide gel. The major portion of the lactating mammary gland RNA directed synthesis of the milk protein in the cell-free system appeared to be analogous to alphas casein,     

The androgenic regulation of the activities of enzymes engaged in the synthesis of deoxyribonucleic acid in rat ventral prostate gland.

The restoration of mitosis and growth of the prostate gland of castrated animals by androgens provides a favourable experimental system for studying the hormonal regulation of enzymes engaged in DNA replication. 2. Many DNA polymerase activities were identified in the prostate gland, but only a 9S form with a particular preference for denatured DNA as template was conspicuously enhanced by androgenic stimulation. 3. Thymidine kinase also provided a sensitive indicator of the hormonal regulation of DNA replication, and on electrophoretic criteria, one discrete form of the enzyme appeared precisely with the onset of mitoris. 4. Evidence is presented to support the view that DNA ligase activity is intimately associated in the process of DNA replication in the prostate gland. 5. A spectrum of deoxyribonuclease activities is present in the prostate gland, but only one form (pI7.0) can safely be said to be implicated in the process of DNA replication. 6. Androgenic stimulation of the prostate gland leads to the appearance of a component capable of denaturing or unwinding prostate DNA. This component is seemingly distinct from RNA or DNA polymerase activities on the basis of several distince physicochemical characteristics. 7. The conspicuous feature of all the changes in enzyme activities evoked by androgens in the prostate gland is their acute tissue- and steroid-specificity. Such changes could not be mimicked in liver or spleen and the regulatory role of androgens could not be simulated by other classes of steroid hormones. Particularly on the basis of studies with the anti-androgen cyproterone acetate, it is concluded that the changes are initially mediated by the androgen-receptor system and the high-affinity binding of 5alpha-dihydrotestosterone in the prostate gland. 8. The results are discussed in the context of the mechanism of action of androgens.     

How to Study Basement Membrane Stiffness as a Biophysical Trigger in Prostate Cancer and Other Age-related Pathologies or Metabolic Diseases

Here we describe a protocol that can be used to study the biophysical microenvironment related to increased thickness and stiffness of the basement membrane (BM) during age-related pathologies and metabolic disorders (e.g. cancer, diabetes, microvascular disease, retinopathy, nephropathy and neuropathy). The premise of the model is non-enzymatic crosslinking of reconstituted BM (rBM) matrix by treatment with glycolaldehyde (GLA) to promote advanced glycation endproduct (AGE) generation via the Maillard reaction. Examples of laboratory techniques that can be used to confirm AGE generation, non-enzymatic crosslinking and increased stiffness in GLA treated rBM are outlined. These include preparation of native rBM (treated with phosphate-buffered saline, PBS) and stiff rBM (treated with GLA) for determination of: its AGE content by photometric analysis and immunofluorescent microscopy, its non-enzymatic crosslinking by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) as well as confocal microscopy, and its increased stiffness using rheometry. The procedure described here can be used to increase the rigidity (elastic moduli, E) of rBM up to 3.2-fold, consistent with measurements made in healthy versus diseased human prostate tissue. To recreate the biophysical microenvironment associated with the aging and diseased prostate gland three prostate cell types were introduced on to native rBM and stiff rBM: RWPE-1, prostate epithelial cells (PECs) derived from a normal prostate gland; BPH-1, PECs derived from a prostate gland affected by benign prostatic hyperplasia (BPH); and PC3, metastatic cells derived from a secondary bone tumor originating from prostate cancer. Multiple parameters can be measured, including the size, shape and invasive characteristics of the 3D glandular acini formed by RWPE-1 and BPH-1 on native versus stiff rBM, and average cell length, migratory velocity and persistence of cell movement of 3D spheroids formed by PC3 cells under the same conditions. Cell signaling pathways and the subcellular localization of proteins can also be assessed.     

The effect of testosterone propionate, 5 alpha-dihydrotestosterone and 5 alpha-androstan-3 beta, 17 beta-diol on acid phosphatase activity in the prostate of castrated rats

The acid phosphatase is studied in the prostate gland of rats. It is shown that 10 days after gonadectomy the activity of acid phosphatase lowered considerably. Administration of testosterone propionate or 5 alpha-dihydrotestosterone to castrated animals restored the enzyme activity whereas 5 alpha-androstan-3 beta,17-diol was not effective. Administration of testosterone propionate with one of its metabolites increased the activity of acid phosphatase in the prostate gland, however to a less extent than with the use of the hormone itself. The lowest activity is detected with the simultaneous application of three androgens.     

ADP-ribosylation of nuclear proteins in rat ventral prostate during ageing

Poly(ADPR)polymerase activity and poly(ADP-ribosyl)ation of nuclear proteins have been investigated in ventral prostate nuclei of different aged rats (14, 28, 60, 180, 360 day old animals), by reverse-phase HPLC and acetic acid-urea polyacrylamide gel electrophoresis. The major ADP-ribose acceptor proteins were identified as histone H1 and H2b. It is concluded that concomitant with major changes to chromatin organization, poly(ADP-ribosyl)ation reaction is progressively inhibited during aging of rat ventral prostate. These results support the hypothesis that prostatic dysfunction in senescent animals is related to a failure of DNA repair mechanisms and deregulated template activity.     

Intracellular localization of Prostatic Binding Protein (PBP) in rat prostate by light and electron microscopic immunocytochemistry

Extra- and intracellular distribution of Prostatic Binding Protein (PBP) was studied in the different genital organs of the male rat by immunocytochemistry at the light and electron microscopic levels. PBP was extracted from cytosols of rat ventral prostate and used for immunization of rabbits. The specificity of the antiserum raised was tested by "western blotting" and immunoelectrophoresis. From the different fixatives tested for optimal structural and antigenic preservation of the ventral prostate a mixture containing 2.5% paraformaldehyde, 0.5% glutaraldehyde and 0.5% CaCl2 in cacodylate buffer, 0.05 M, pH 7.3 was selected. Using the immunofluorescence technique and the unlabeled antibody enzyme method PBP-immunoreactivity was detected at the light microscopic level in the luminal secretions of the ventral prostate. No reaction was observed with the seminal vesicle, the coagulating gland, the dorsal and lateral prostates, the epididymis and the testis. Intracellular secretory granules reacting with PBP antiserum were exclusively found in the secretory cells of the ventral prostate. Insufficiently fixed cells showed a diffuse generalized reaction of the cytoplasm indicating a leakage of the antigen from the secretory granules. Such artifacts were common in tissue sections processed with the preembedding-staining procedure. At the ultrastructural level therefore mostly the postembedding staining method was performed using both the unlabeled antibody enzyme method and the ferritin-labeled immunoglobulin technique in osmicated, Epon-embedded tissue. Labeling with either method was intense in the secretory granules and the condensing vacuoles, while the labeling density of the rough endoplasmic reticulum and the Golgi cisternae was in the background range. Castration experiments showed that secretory material displaying PBP immunoreactivity was retained within the acinar lumen of the gland for several days after castration, but was absent from most secretory cells already by four days after castration. Immunocytochemistry of PBP therefore is a very sensitive method for analysing the secretory activity and its androgen dependence of the prostate of the rat.     

Biopsy of the mouse prostate

Many transgenic and knockout mouse models of prostate cancer have become available over the past decade. In this paper we describe a simple biopsy technique of the murine prostate. This technique allows sequential follow-up of the prostate in an individual mouse. Its use could also reduce the number of mice used in studies of the prostate gland.     

Histoenzymological comparison of the prostate gland of sexually 'quiescent' and 'active' Taphozous melanopogon melanopogon Temmnick (Microchiroptera: Mammalia)

Lysosomal hydrolases (e.g., acid phosphatase, AcPase; adenosine triphosphatase, ATPase, and lipase) and the mitochondrial 'marker' enzyme succinic dehydrogenase (SDH) were evaluated histochemically in the prostate gland of sexually 'quiescent' and 'active' bats. During the former state, AcPase activity was significantly less than in sexually active animals, suggesting that prostate AcPase activity is androgen dependent. Levels of lipase activity also were highest in the prostate of sexually active bats, suggesting the importance of endogenous lipids which may be mobilized and used as a source of energy. SDH and ATPase sites and patterns of distribution in the prostate gland of bats were closely similar during the two reproductive states. Differential enzymological patterns do not seem to have any significant correlation with the morphological changes which occur in the glandular epithelium, musculature, urethra and the luminal fluid, as the animals pass from a 'quiescent' phase to one of activity and vice versa as observed in the present study.     

Development of the rat salivary glands. II. The identification of a trypsinlike protease in the submaxillary gland

Trypsinlike protease activity at pH 9.2 was measured in tissue extracts of adult rat salivary glands by using a fluorometric assay in which β-naphthylamine is released by the hydrolysis of benzylarginine β-naphthylamide. The submaxillary gland contains high levels of this activity, and the parotid and sublingual glands have a maximum of 2000-fold and 200-fold less. After polyacrylamide disc gel electrophoresis at pH 8.3, the protease activity of submaxillary extracts is associated with a major protein band. Neither this protein band nor its protease activity is detectable in extracts of parotid or sublingual glands. Homogenates of newborn submaxillary gland do not have this protease activity at detectable levels, suggesting that its major accumulation is postnatal.     

Age-dependent expression of 5alpha-reductase and androgen receptors mRNA by the canine prostate

The growth of the prostate gland is androgen-dependent. Testosterone is converted to the most potent dihydrotestosterone (DHT) by 5alpha-reductase within the prostate. Androgen interacts with androgen receptors (AR) to regulate normal growth of the prostate and has also been implicated in both the progression of benign prostate hyperplasia and prostate cancer. This study was conducted to compare the mRNA expression of AR and 5alpha-reductase by the prostate gland from three age categories: immature, young-mature and old dogs. Quantitative gene expression was assessed by the real-time PCR and the results were expressed as a relative mRNA expression of the target gene. This study revealed that there was no significant difference in the mRNA expression of the AR gene by the prostate gland of immature, young and old dogs. In contrast, there is a highly significant (P<0.001) down-regulation in 5alpha-reductase gene by the prostate of young and old dogs as compared with immature dogs. However, there is no significant difference in mRNA expression of the 5alpha-reductase gene by the prostate gland from young and old dogs. This differential expression of AR and 5alpha-reductase genes, which are involved in the regulation of androgen effect on prostate gland, might reflect an age-dependent growth requirement of the gland for androgens.     

猕猴精浆纤溶酶原激活因子的来源及在精子获能中的作用

我们的前期工作表明,不育症人精液中纤溶酶原激活因子（plasminogen activator;PA）活性明显升高;给成年办和猕猴注射长效睾酮诱发无精过程中,精液PA含量也伴随上升,为进一步查明PA的来源和对精子的作用,原位杂交检测组织型PA（tPA）,尿激酶型PA（uPA）及PA抑制因子－1（PAI-1)泊mRNAs在成年健康猕附睾、前列腺和精囊中的表达。体外培养猕猴精子,培液中加入uPA、tPA及其底物纤溶酶原（plasminogen）,测试PA对精子活力、顶体反应及激活卵子的影响。结果表明,猕猴附睾、前列腺和精囊均表达tPA、uPA和PAI-1 mRNAs。加入uPA能维持精子的活力,使精子产生超激活运动,诱导顶体反应的发生,并使精子获得激活卵子的能力,这说明猕猴精浆PA除来源于睾丸外,可能主要来源于附睾及附性腺;在体外,uPA,而不是tPA,可能诱导精子获能。     

Epithelial and stromal cell relation in peritumorous zone of the prostate gland cancer

This article deals with an urgent topic--assessment of peculiar characteistics of epithelial-stromal interactions in prostate gland tissues outside the tumor growth zone. On demonstrating pre-cancerous changes, this zone can either further accompany or precede the development of malignant neoplasm. The authors have established suppression of general morpho-functional activity of histogematogenous barrier components, increase in degenerative changes in epithelium, both in the vicinity of the tumor, and at a distance from it, which is, most probably, caused by dishormonal changes. We demonstrated the growth of lymphocytic-monocytic infiltration, and a decreased number of fibroblasts and endothelial cells of prostate gland tissues outside the tumor growth zone. The discovered changes of the histogematogenous barrier condition in the peritumorous zone and the benign hyperplasia can serve an additional criterion for early diagnostics of pre-cancerous changes of the prostate gland.