The ultrastructure of the accessory sex organs of the male rat. II. The post-castration involution of the ventral, lateral and the dorsal prostate

Macrophage roles in the clearance of apoptotic cells and control of inflammation in the prostate gland after castration

BACKGROUND

Androgen deprivation results in massive apoptosis in the prostate gland. Macrophages are actively engaged in phagocytosing epithelial cell corpses. However, it is unknown whether microtubule-associated protein 1 light chain 3 alpha (LC3)-associated phagocytosis (LAP) is involved and contribute to prevent inflammation.

METHODS

Flow cytometry, RT-PCR and immunohistochemistry were used to characterize the macrophage subpopulation residing in the epithelial layer of the rat ventral prostate (VP) after castration. Stereology was employed to determine variations in the number of ED1 and ED2. Mice were treated with either chloroquine or L-asparagine to block autophagy.

RESULTS

M1 (iNOS-positive) and M2 macrophages (MRC1+ and ARG1+) were not found in the epithelium at day 5 after castration. The percentage of CD68⁺ (ED1) and CD163⁺ (ED2) phenotypes increased after castration but only CD68⁺ cells were present in the epithelium. RT-PCR showed increased content of the autophagy markers Bcl1 and LC3 after castration. In addition, immunohistochemistry showed the presence of LC3⁺ and ATG5⁺ cells in the epithelium. Double immunohistochemistry showed these cells to be CD68⁺ /LC3⁺ , compatible with the LAP phenotype. LC3⁺ cells accumulate significantly after castration. Chloroquine and L-asparagine administration caused inflammation of the glands at day 5 after castration.

CONCLUSIONS

CD68⁺ macrophages phagocytose apoptotic cell corpses and activate the LAP pathway, thereby contributing to the preservation of a non-inflammed microenvironment. Marked inflammation was detected when autophagy blockers were administered to castrated animals.

Desquamation takes center stage at the origin of proliferative inflammatory atrophy, epithelial-mesenchymal transition, and stromal growth in benign prostate hyperplasia

In this commentary, we propose a relationship between desquamation, initially described as the collective detachment and deletion of epithelial cell in the prostate gland after castration, and proliferative inflammatory atrophy (PIA) and stromal growth in benign prostate hyperplasia (BPH). First, in response to diverse stimuli, including inflammatory mediators, epithelial cells desquamate and leave a large surface of the luminal side of the basement membrane (BM) exposed. Basal cells are activated into intermediate-type cells, which change morphology to cover and remodel the exposed BM (simple atrophy) to a new physiological demand (such as in the hypoandrogen environment, simulated by surgical and/or chemical castration) and/or to support re-epithelialization (under normal androgen levels). In the presence of inflammation (that might be the cause of desquamation), the intermediate-type cells proliferate and characterize PIA. Second, in other circumstances, desquamation is an early step of epithelial-to-mesenchymal transition (EMT), which contributes to stromal growth, as suggested by some experimental models of BPH. The proposed associations correlate unexplored cell behaviors and reveal the remarkable plasticity of the prostate epithelium that might be at the origin of prostate diseases.

Morphological changes in mouse accessory sex glands following neonatal estrogen treatment

A single injection of beta-estradiol 17-cypionate into the mice within 5 hr after birth induced inflammation in all prostate lobes and the seminal vesicles. Neutrophils emigrated into the lumen through the basal lamina and epithelium of the seminal vesicle and the anterior prostate. Local infiltration of lymphocytes was observed in the stroma and epithelium of ventral prostates. Lymphocytes penetrated through smooth muscle cells into epithelium. This could support the hypothesis that smooth muscle cells are the target of the estrogen action of prostates in estrogenized animals.

Two types of three-dimensional structures formed by epithelial cell aggregates from the rat ventral prostate in collagen gel culture. The amount of activated charcoal for absorbing serum

Cells taken from the rat ventral prostate and cultured formed a tubular structure inside the collagen gel in a medium containing activated charcoal-absorbed serum after a 14-day incubation. This might suggest that the active substances of serum could induce isolated epithelial cells to form such a spherical or tubular structure, depending on the amount of activated charcoal used for the absorption of serum.

Androgen metabolism in the different lobes of the prostate gland of intact, gonadectomized or hypophysectomized rats with or without androgen substitution

The effect of gonadectomy or hypophysectomy and the effect of substitution with testosterone, upon the reductive and oxidative metabolic transformations of testosterone, 4-androstene-3,17-dione, 17 beta-hydroxy-5 alpha-androstane-3-one, 5 alpha-androstane-3 alpha, 17 beta-diol and 5 alpha-androstane-3 beta, 17 beta-diol using NAD(H) and NADP(H) as added cofactors were examined in homogenates from the ventral (VP), lateral (LP) and dorsal prostate (DP), and coagulating gland (CG) of adult Wistar rats. The fall in serum testosterone induced by gonadectomy or hypophysectomy led to reduced activity of 5 alpha-reductase, NADP(H)-dependent 3 alpha-hydroxysteroid oxidoreductase (3 alpha-HSOR), NAD-dependent 3 alpha-HSOR, 3 beta-HSOR and 17 beta-HSOR, indicating that these enzymes are androgen dependent. The NADP dependent oxidation of 5 alpha-androstane-3 alpha, 17 beta-diol in LP increased upon hypophysectomy and gonadectomy. Testosterone substitution of gonadectomized or hypophysectomized rats generally maintained enzymatic activity at the level of the control group, except for the 5 alpha-reductase activity which fell in spite of this treatment. Hypophysectomy or gonadectomy had different effects on the activity of several androgen metabolizing enzymes; 5 alpha-reductase activity in DP and CG, NAD(H) dependent 3 alpha-HSOR in VP and NADPH dependent 3 beta-HSOR activity in LP, DP and CG. There were marked differences between the rat prostatic lobes, both concerning the activity of the androgen metabolizing enzymes and the responses to the different treatment modalities.

The effect of androgen and estrogen on secretory epithelial cells and basal cells of the rat ventral prostate after long-term castration

After long-term castration, rats were injected with cotton seed oil, testosterone- and estradiol-17 beta-cypionate (CS, TC and EC). The height of the epithelial cells of the ventral prostates from the castrated rats increased after TC and EC-injection. The secretory and basal cells formed two layers of epithelium, an inner layer near the lumen with pale nuclei and another layer with dark nuclei. These two layers could result from a reduction of secretory epithelial cells. Castration decreased the ratio of secretory cells to basal cells (S/B). TC-injection increased the ratio of S/B because of the secretory epithelial cell growth. Longer dark cells may be transient cells, appearing during the differentiation of basal cells into secretory epithelial cells. A sheet branching off from the basal lamina was observed. Androgen may stimulate the synthesis of the lamina, but whether it induces the synthesis or turnover of the basal lamina has not been established. EC increased the ventral prostatic weight and secretory epithelial cell height and induced the appearance of crystalline granules. Increase in S/B ratio may result from an increase in the secretory epithelial cells, but not from basal cell multiplication due to squamous metaplasia. The ratio is significantly correlated to the weight of the ventral prostate, but not to the secretory epithelial cell height. Its value could indicate the multiplication of secretory epithelial cells, differentiation of basal cells into epithelial cells, or both. It is probable that basal cells do not change in number, but control the size of the rat ventral prostate in response to the hormone level.

Immunocytochemical localization of cathepsin D in rat ventral prostate: evidence for castration-induced expression of cathepsin D in basal cells

Cathepsin D (EC3.4.23.5) is an aspartyl endopeptidase involved in lysosomal proteolysis. Its functional role is uncertain. This study was undertaken to determine the cellular and subcellular distribution of cathepsin D in the normal rat ventral prostate and its possible role in the castration-induced atrophy of the gland. Cathepsin D was localized immunohistochemically to perinuclear lysosomes in secretory cells, in capillary endothelial cells, and, occasionally, in stromal cells of the untreated animal. Castration resulted in an increased number of cathepsin D-positive cells in the stroma within 24 hr. By 48 hr after castration autophagolysosomes formed in secretory cells and apoptotic bodies appeared in the epithelium. Although apoptotic bodies generally contained immunoreactive cathepsin D, a subpopulation of larger apoptotic bodies, which commonly rested on the basement membrane and contained multiple inclusions, were more variable in cathepsin D expression. The induction of cathepsin D in dendritic cells basally oriented in the epithelium was noted at 4 days of castration. These cells had a phagocytic phenotype, were distributed periodically along the basement membrane, and were not found in ductal epithelia. Treatment with actinomycin D or hydrocortisone to reduce the rate of regression of the ventral prostate blocked the appearance of these cathepsin D-positive, basally oriented epithelial cells. Our data indicate that this cathepsin D-positive, phagocytic cell differentiates from a cell resident in the prostatic epithelium. We suggest that it differentiates from basal cells in the secretory tubuloalveolar portion of the gland and that it is involved in the destruction of regressed secretory cells.

Ultrastructural changes in thyroid epithelium during involution of the hyperplastic thyroid gland

The ultrastructure of the thyroid epithelial cell was examined at various time intervals after induction of involution of the hyperplastic thyroid gland. Thyroids were made hyperplastic by the feeding of thiouracil in a Remington low-iodine diet to male Fischer rats for 3 weeks. Involution was induced by replacing the thiouracil-containing diet with Purina Laboratory Chow, a high-iodine diet. During involution, organelles that play a role in the synthesis and secretion of thyroglobulin, such as the rough endoplasmic reticulum, Golgi apparatus, and apical vesicles, were well preserved and prominent features of the epithelial cell. The apical plasma membrane of many cells was highly irregular for approximately 2 weeks with signs suggesting rapid discharge of apical-vesical contents into the lumen of the follicle. Pseudopods and colloid droplets were present but were not very prominent features of the cell. No signs of extensive autophagy or obvious increased incidence of lysosomes were present, although there was an elevation in the incidence of small dense bodies starting about day 8, and prominent by 15 days. Some of these may be phagosomes formed from luminal debris. The observations indicate that involution of the hyperplastic thyroid in which there is maintenance of the protein synthetic apparatus and little sign of autophagy or death of the epithelial cells is remarkably different from phenomena occurring during involution of prostate or mammary glands.

Characterization of castration-induced cell death in the rat prostate by immunohistochemical localization of cathepsin D

Activities of cathepsin D (EC 3.4.23.5) were determined in three lobes of the prostate during their involution by both biochemical and immunohistochemical procedures. The activity of cathepsin D in noncastrated rats was 0.9 +/- 0.2 (mean +/- SE) 5.7 +/- 0.6, and 13.1 +/- 0.8 units/mg protein for the ventral, lateral, dorsal lobes, respectively. Following castration, there was a significant increase in enzymatic activity in all three lobes within 2-3 days. In the ventral lobe, the activity peaked in 5 days to 6.2 +/- 0.9 units/mg protein and declined slightly thereafter. In the lateral and dorsal lobes, the activity remained elevated (14-20 units/mg protein) throughout the postcastration period studied. Immunohistochemical staining of cathepsin D was localized in the cytoplasm of prostatic epithelial cells as fine discrete lysosomal granules. These granules were larger and more abundant in the dorsal and lateral lobes than in the ventral lobe and were not detected in prostatic stromal cells and seldom in the luminal fluid. Castration resulted in an immediate increase in the size and number of these granules in the epithelial cells, followed by a sudden further increase in cathepsin D staining in some but not all epithelial cells. Lysosomal granules gradually coalesced in these cells to form large vacuoles that fit the characteristic description of apoptotic bodies. Finally, after day 7 postcastration, collapse and disintegration of the entire glandular structure was noted. Using this procedure to localize cathepsin D as a tool, we were able to follow the morphological events of prostatic cell death during castration-induced involution in the rat at the light microscopic level.

Relationship between DNA fragmentation and apoptosis in the programmed cell death in the rat prostate following castration

Previous studies have demonstrated that the rapid involution of the rat ventral prostate following castration involves the death of the androgen-dependent epithelial cells present within the gland and that this death is the result of a series of discrete biochemical steps. The degradation of genomic DNA into nucleosomal-sized fragments is an early event in this process and is catalyzed by calcium magnesium-dependent endonuclease activity. The morphologic correlation of the involution process involves a series of structural changes which are collectively referred to as apoptosis. The apoptotic process describes the earliest apparent signs of morphologic change exhibited by the dying cells through their eventual complete destruction and deletion from the tissue. The temporal relationship between these recently described biochemical events and the morphologic changes of the apoptotic process were compared in the present study, in order to test the cause versus effect nature of DNA fragmentation in the programmed death of androgen dependent prostatic cells following castration. These studies demonstrated that the early elevation of the Ca+2 Mg+2-dependent endonuclease activity and the fragmentation of DNA into nucleosomal oligomers occurs within prostatic glandular epithelial cells and probably does not involve the direct participation of extraprostatic cells which may subsequently migrate into the gland. Once the DNA is initially cleaved into the nucleosomal oligomers, the subsequent participation of lysosomal enzymes act in a less restricted fashion to degrade both the nucleosomal DNA as well as the cytoplasmic elements and the cell becomes morphologically apoptotic. As the elevations in Ca+2 Mg+2-dependent endonuclease activity and DNA fragmentation are initiated at a time well before the cell is morphologically dead, as defined by apoptosis, these changes in DNA metabolism must not be the consequences of cell death but instead are early causal events in an active process of programmed cell death.

The Ca2+-dependent protease inhibitor of rat ventral prostate: properties of the inhibitor and effects of castration on Ca2+-dependent protease and inhibitor activities

1. The rat ventral prostate contains a heat stable inhibitor of Ca2+-dependent protease. This inhibitor was found to exist in a wide range of molecular weights (approx. 40-270 kDa) in adult rats. 2. However, in rats immediately post puberty (45 days of age) the inhibitor was predominantly of the higher molecular weight forms. 3. The inhibitor was also found in the dorsolateral and anterior (coagulating gland) prostate lobes but was of lower specific activity than in the ventral lobe. 4. Although the activities of the Ca2+-dependent protease and inhibitor decreased per ventral prostate gland after castration, these activities were not different during the first 10 days postcastration when expressed per g wet wt or per unit cytosol protein. 5. With a longer duration of castration, there was a decline in the specific activity (per unit protein) of the protease and an increase in that of the inhibitor. 6. Thus, the activities of the protease and inhibitor change in concert with the amount of cellular cytosol protein during the active period of castration-induced atrophy. 7. However, in long term castrated rats, functions carried out by the Ca2+-dependent protease may be effectively suppressed. 8. These data suggest that the Ca2+-activated protease probably is involved in the regulation of some metabolic processes in the active gland and is not prominent in the castration induced atrophy of the ventral prostate unless it functions through the proteolysis of some select protein(s).

Light microscopic morphometric analysis of castration effects in the different lobes of the rat prostate

The morphologic effects of androgen deprivation in the different lobes of the rat prostate were examined by light microscopic morphometry. The prostates of Wistar male rats (260-340 g) were fixed in situ by glutaraldehyde perfusion in castrated animals 1 week after gonadectomy and in intact animals. The ventral (VP), dorsal (DP), and lateral (LP) lobes as well as the coagulating gland (CG) were dissected out, weighed, and processed for light microscopy. Using stereologic methods the following parameters were estimated for each lobe: volume fraction of connective tissue, epithelium and glandular lumina, average epithelial height, average epithelial cell volume, and total number of epithelial cells. Castration leads to a 58-76% reduction of the wet weight of all prostatic lobes. The decrease of glandular tissue is greater in VP than in LP, DP, and CG. In VP and LP, there is a 39-45% reduction of the epithelial height, and this effect is less pronounced in DP and CG. For all lobes, the shrinkage of average epithelial cell volume is in the same range (25-30%). Moreover, in VP and LP, there is a 70% reduction of the total number of cells, whereas the reduction is less in DP and CG. It thus seems that the reduction of prostatic epithelial tissue mass upon castration is due to a reduction of the number of cells as well as a reduction of the volume of individual cells. VP and LP appear to be more androgen-dependent than DP and CG.

Primary culture of epithelial cells derived from the rat ventral prostate: formation of three-dimensional acinus-like structure in collagen gel

Rat ventral prostate epithelial cells were cultured in collagen gel after collagenase digestion. The primary cultures were mainly composed of single and spherical cells. After 10 days incubation in growth medium containing insulin, transferrin, and cholera toxin, there was a 3.8-fold increase in cell numbers, aggregates of which formed three-dimensional acinus-like structures. These structures consisted of one layer of cells surrounding the lumen. The cells were joined together with a junctional complex and had microvilli on the luminal surface and secretory vacuoles in the cytoplasm facing the lumen. The ultrastructural features of the cells were not altered by growth medium containing steroids. This culture system may prove to be very useful in elucidating proliferation, organization, and differentiation of prostatic epithelial cells in relation to the extracellular matrix and stromal cells.

Ultrastructure and immunohistochemistry of the lateral prostate in aged rats

Ultrastructural, histological, and immunohistochemical studies were performed on lateral prostates of 1) aged rats from different strains, 2) rats permitted different levels of sexual activity, and 3) castrated rats. Antibodies against the following proteins were used as immunohistochemical markers: SVS II from seminal vesicle, LP 28 from lateral prostate, acid phosphatase isoenzymes from ventral prostate, transglutaminase from coagulating gland, and a commercial monoclonal antibody against cytokeratin. SVS II is a marker of lateral prostatic secretion, while immunoreactions to LP 28 and acid phosphatase (pI 7.1) were cytoplasmic. In aged animals the amount of intracellular secretion is decreased, and focally metaplastic transformation can be visualized by using immunohistochemical markers. Epithelial ultrastructure varied considerably with experimental conditions. Intensive sexual activity resulted in increased polymorphism and increased number of secretory granules within the glandular cells, while castration was followed by a rapid loss of secretory material. Also, in rats older than 10 months, a reduction in the number of secretion granules was common. The epithelium developed a positive immunoreaction to transglutaminase antibodies that were not observed in juvenile glands. Cells, presumably macrophages, which had an intense immunoreactivity for transglutaminase, were increased in number both within and outside the prostatic acini of aged rats. The possible interaction between secretory SVS II, a substrate of transglutaminase, the release of this enzyme from macrophages or its reflux from coagulating glands, the spontaneous cellular exfoliation that is due to decreased androgen levels, and dietary noxae may be of importance in the development of lateral prostatic nonbacterial inflammation in aged rats.

Cell proliferation studies in the rat prostate: II. The effects of castration and androgen-induced regeneration upon basal and secretory cell proliferation

The changes over short and prolonged periods (up to three months) after castration on the proliferative activity of basal and secretory epithelial cells in the rat prostate were studied. Although castration induced widespread apoptosis of the secretory cells, no compensatory hyperplasia of the basal cells in response to this was noted. Instead, observations of the cell kinetics and ultrastructure suggested that both the basal and secretory cells entered a quiescent state as a result of castration. The proliferative potential of secretory cells was not diminished up to three months after castration. During androgen-induced regeneration of the prostate the pattern of basal and secretory cell proliferation was found to be similar to that observed during normal growth, although it was more rapid and of shorter duration.

Metabolism of androgens in the seminal vesicles and the different lobes of the prostate in young mature rats

Oxidation and reduction of 4-androstene-3,17-dione (androstenedione), 17 beta-hydroxy-4-androsten-3-one (testosterone), 17 beta-hydroxy-5 alpha-androstan-3-one (DHT), 5 alpha-androstan-3 alpha,17 beta-diol (3 alpha-A'diol) and 5 alpha-androstane-3 beta,17 beta-diol (3 beta-A'diol) were measured in homogenates from ventral (VP), dorsal (DP) and lateral prostate (LP), the coagulating gland (CG) and seminal vesicle (SV) of the intact sexually mature rat using NAD(H) or NADP(H) as cofactors. The specific activity of the various enzymes varied significantly between the different organs. 5 alpha-Reductase activity was highest in the DP and the CG, and undetectable in the LP. 17 beta-Hydroxysteroid oxidoreductase (17 beta-HSOR) activity was mainly confined to the LP. 3 alpha-Hydroxysteroid oxidoreductase (3 alpha-HSOR) activity was also highest in the LP. In the VP the highest 3 alpha-HSOR activity was recorded using NAD(H) as cofactor. In the other organs, similar or higher enzymatic activities were measured using NADP(H) as added cofactor. 3 beta-Hydroxysteroid oxidoreductase (3 beta-HSOR) activity was high in the LP and low or undetectable in the other tissues. Our results indicate that isoenzymes of 3 alpha-HSOR, 3 beta-HSOR and 17 beta-HSOR are present in the accessory sex organs of the rat.

A stereological study of the effects of the pineal gland on the ventral prostate of the rat

Several procedures known to influence pineal gland secretion were studied for their effects on the ventral prostate of rats. Stereological measurements were made of volume fractions of acini and glandular epithelium, surface fractions of glandular epithelium, and length fractions of acini. From these figures and the weights of the glands, the volumes, surface areas, and lengths of these features were calculated, as well as the mean epithelial heights, mean acinar diameters, and mean distances between glandular acini. None of these measurements differed in sham-operated controls, pinealectomized, or blinded rats. In blind-anosmic rats, however, there were significant decreases in the weights of the prostates and the volumes of the acini, reflecting significant decreases in the mean diameters of acini. None of the other parameters differed from those of controls, except the length fraction of acini. These results differ from those described by others following castration in rats, indicating that the action of the pineal gland on the ventral prostate may be different from that of androgen deprivation, in this species. Caution should therefore be exercised in the interpretation of the results of experiments in which prostate weights are used as indications of the actions of pineal hormones on the neuroendocrine-gonadal axis.

Androgen receptor binding characteristics in the cytosol of the rat dorsolateral prostate gland and the Dunning R-3327 prostatic adenocarcinoma

The incidence of prostatic cancer is highly correlated with advanced age, and it has been suggested that changes in androgen binding may be important in age-associated alterations in growth regulatory mechanisms of prostatic epithelial cells. In this study the effects of age on androgen binding characteristics in the dorsolateral prostate glands of young and aged Copenhagen rats were determined and the binding properties in the Dunning R3327/130 subline of rat prostatic adenocarcinoma were characterized. Tritium-labeled and nonlabeled methyltrienolone analogs (R1881) were used to study the binding properties of 5 alpha-dihydrotestosterone receptor in the cytosol of tumors and prostate glands. Binding of R1881 was low but specific for the androgen receptor as shown by competition studies in which nonlabeled R1881, 5 alpha-dihydrotestosterone, and testosterone competed successfully with 3H-R1881 for binding sites, but 17 beta-estradiol and low levels of progesterone did not. In Copenhagen dorsolateral prostate, Scatchard analysis suggested a single class of binding sites. In young animals (three to five months) the average binding capacity was 10.36 fmol/mg cytosol protein with a dissociation constant (Kd) of 2.28 nmol/L. The dorsolateral prostate of aged rats (11-16 months) showed no significant difference in specific binding characteristics as compared to the younger age group. Specific binding of 3H-R1881 in R3327/130 tumor was saturable with a single class of high-affinity binding sites having an average binding capacity of 64.77 fmol/mg cytosol protein and a Kd of 2.76 nmol/L. These data show that the tumor had approximately 6.5 times the number of binding sites as did the normal Copenhagen rat dorsolateral prostate gland. However, no age-related changes were detected through 11-16 months of age in the androgen binding characteristics of normal rat dorsolateral prostate gland that could be correlated with the higher concentration of androgen binding sites in the R3327/130 tumor subline.

Animal model of isolated gonadotropin deficiency. II. Morphologic responses to LHRH immunoneutralization

Morphologic changes in the male reproductive system of mongrel dogs immunized against LHRH were quantitated using linear measurements and morphometric techniques at the light-microscopic level. Two experimental groups (5 nonimmunized control animals and 5 actively immunized animals) were killed 12 weeks after the primary immunization. No significant differences were observed between three immunized dogs having low LHRH antibody titers (immunized-unaffected) and the five nonimmunized control dogs. The two immunized dogs (affected) with the highest antibody titers against LHRH were characterized by atrophy and dedifferentiation of the testes, prostate, and excurrent ducts. The morphologic changes in the testes of these two dogs were striking and included an apparent arrest or significant reduction in the spermatogenic process, concurrent epithelial degeneration, and apparent diminution of Leydig cell mass. Drastic reductions in the size of the prostatic acini and epithelial cells, as well as loss of secretory granules, reflected depression of function and androgen production. Similarly, in the excurrent ducts decreases in the measured parameters and loss of regional cytoplasmic specialization denoted functional decrescence. This study demonstrates the regressive effects of LHRH immunoneutralization on the morphology of the reproductive system in the male dog and further supports the feasibility of this system as an animal model for the study of isolated gonadotropin deficiency.

Ultrastructural and analytical studies on the prostate of castrated rats

Rat lateral and ventral prostate tissue was studied using ultrastructural and analytical techniques in adult animals castrated for periods of 3 to 20 days. As in previous reports involution of the prostatic epithelium following testosterone deprivation resulted in alterations of the amount, distribution, and conformation of the endoplasmic reticulum, Golgi, and lysosomes in addition to some nuclear changes. Although the fundamental changes were similar in both lobes there were specific effects on the individual lobes. Reductions in the subcellular levels of zinc were more pronounced in the lateral prostate, particularly with respect to the secretory and stromal concentrations of the metal. Despite low concentrations of circulating testosterone, secretory activity was still evident after a 20-day castration period and would appear to reflect a different sensitivity in the lateral lobe to the lowered testosterone level or stimulation by other hormones when compared to the ventral lobe. The significance of the subcellular distribution pattern of zinc during the experimental periods is discussed in relation to the possible functional significance of the metal in prostatic tissue.

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.

Freeze-fracture, ultrastructural and autoradiographic analysis of the ventral prostate glands in castrated mice

Ultrastructure of the ventral prostate glands was studied in mice castrated for 1 through 60 days and for 11 and 17 months and in age-matched normals. We have described freeze-fracture and ultrastructural characteristics of acinar epithelial cells in addition to the patterns of thymidine incorporation in the cells of castrates and normal animals. Our study has shown a biphasic pattern of prostatic involution in the long-term castrated mice. In castrates the initial atrophy of prostate glands occurred by sloughing of the apical portions of columnar cells, autophagia of the cytoplasmic organelles as well as by occasional sloughing of the individual cells into the acinar lumen. Concurrent with the initial atrophy, the glands and stroma were infiltrated by neutrophils and lymphocytes. The cell loss by sloughing and leucocyte infiltration of glands became infrequent in 7- to 21-day castrates. However, the cell loss by sloughing increased secondarily in mice castrated for 21 to 37 days along with the increased leucocyte infiltration of the glands. The cell loss became minimal in castrates of 60 days and beyond. Our evidence suggests that the cell loss by sloughing was an active process in the involution of prostate glands which also showed differential sensitivity to castration stimuli in mice.

The effect of cadmium administration in vivo on plasma testosterone and the ultrastructure of rat lateral prostate

Electron microscope microanalysis, atomic absorption analysis and ultrastructural survey were used to investigate the effects of parenteral cadmium administration on the lateral prostate of rats. Early fine structural changes in the epithelial cells of the prostatic tissue were associated with the detection of cadmium in the cellular organelles and alteration of the subcellular distribution of zinc. Involutionary changes appeared at later stages and differed from the usual castration effects. Basal cells did not regress with the altered physiological conditions but appeared to proliferate in the presence of cadmium. The observations are discussed in relation to the normal mechanisms which control the maintenance of the prostate gland.

Specific protein synthesis in isolated epithelium of guinea-pig seminal vesicle. Effects of castration and androgen replacement

Four intrinsic soluble secretory proteins are synthesized in vitro by isolated seminal-vesicle mucosa from sexually mature guinea pigs. Newly synthesized specific proteins labelled with [(14)C]glycine and [(14)C]lysine were precipitated by using double-antibody immunoprecipitation techniques and their radioactivity was assessed. Rates of synthesis were determined on each of 5 days after castration. By 5 days after castration the wet weight of the epithelium decreased to 42% of intact control values; the absolute amount of specific protein synthesized in vitro after 60min incubation decreased to 28% and the 27500g cytoplasmic protein content decreased to 31%. Thus androgen deprivation leads to a decrease in general protein synthesis in vivo, as well as to a decrease in specific protein synthesis in vitro. Specific protein synthesis comprised 76% of the total protein formed in isolated tissue from animals 5 days after castration as compared with 99-100% in tissue from intact animals. At 72h after an injection of testosterone or dihydrotestosterone, seminal-vesicle epithelium wet weight, cytoplasmic protein content and capability for synthesizing specific proteins in vitro were restored to approx. 70% of normal values. At 72h after onset of therapy with 3alpha-androstanediol, both epithelium wet weight and cytoplasmic protein content had increased significantly, but without a corresponding increase in the capability of the isolated tissue to synthesize specific proteins. The soluble labelled proteins synthesized in vitro by isolated epithelium from intact animals during 60 or 120min incubation were essentially entirely immunoprecipitable, i.e. specific. In contrast, approx. 29% of all soluble protein newly synthesized by isolated epithelium from animals 5 days after castration was acid-precipitable, but not immunoprecipitable, i.e. ;non-specific'. The injection of testosterone into castrated animals inhibited the synthesis of the non-specific fraction by isolated tissue. The effects of castration on the ultrastructure of guinea-pig seminal-vesicle epithelium are also presented.

Lipopigment fine structure in human seminal vesicle and prostate gland epithelia

The fine structure of lipopigments normally found in prostatic and seminal vescile epithelial cells of elderly men is described and compared to findings in human fetal and hypophysectomized rat accesory sexglands. In the prostate gland lipopigments are supposed to be a sign of reduced metabolic activity, whereas in the seminal vesicle lipopigment formation seems to indicate not only high functional activity but also regressive changes.

The influence of progestin and androgen on the fine structure of the male reproductive tract of the rat. II. Epididymis and sex accessory glands

Young adult male rats were administered medroxyprogesterone (Provera, Upjohn) alone and in combination with testosterone,as has been done to inhibit male fertility. The histology and the fine structure of several segments of the epididymis, the ventral prostate, and the seminal vesicle were studied at intervals after treatment for up to 16 weeks. The epididymides of treated animals weighed less than those of control rats. Microscopic alterations in the epididymis were similar in rats treated with Provera alone and in those animals that received Provera and testosterone, but the changes varied with the segment of the epididymis. In the middle segment in the caput epididymidis, the normally abundant luminal sperm were absent but the epithelium retained its normal ultrastructural features. In the terminal segment in the cauda epididymidis, different changes were observed in the proximal and distal portions. In the proximal cauda epididymidis, the lumen was small, irregular in outline, and virtually devoid of sperm. The light cells of the epididymal epithelium in the proximal cauda contained extremely large numbers of dense bodies resembling lysosomes, which occupied most of the supranuclear and basal cytoplasm. In contrast, in the distal part of the cauda epididymidis, the epithelium had a normal appearance but the lumen was filled with debris, sperm, and spherical masses of cytoplasm that were apparently derived from germ cells. It is suggested that the clearing of the lumen of the proximal cauda epididymidis may reflect the greater activity of light cells of the epididymal epithelium in that region. Although alterations in spermatogenesis may be most important in the antifertility effect of progestin and androgen, these alterations in epididymal sperm and epithelium may also play a role. The weights of the prostate and seminal vesicles of rats treated with Provera (1 mg/100 g/day) were greatly reduced compared to those of control rats. Although there was considerable variation, in many specimens treated with Provera alone the epithelium of the prostate showed a change from a columnar to a cuboidal or squamous shape, and there was a reduction in the size and abundance of organelles involved in the formation of secretions. The microscopic structure of the seminal vesicle of rats treated with Provera was less severely affected than the prostate. Although the seminal vesicle epithelium of Provera-treated rats was generally not as tall as in control animals, the cells possessed parallel cisternae of rough endoplasmic reticulum, secretory vacuoles, and an active-appearing Golgi apparatus, suggesting that they continued to be able to form secretions in the presence of Provera. The weights of the sex accessory glands were maintained at control levels by the administration of testosterone, 100 mug/100 g/day, along with the Provera. A normal fine structure was present in the epithelium of both the prostate and seminal vesicle of rats administered this amount of testosterone in addition to Provera...

Subcellular distribution of zinc in rat prostate studied by x-ray microanalysis: I. Normal prostate

Zinc is distributed subcellularly throughout the lateral prostate of the rat in both the stromal and epithelial elements. The connective tissue appears to be a major store of zinc. Within the epithelium, the highest concentrations of the element are found in the lysosomes, nucleoli, nuclear chromatin, secretory granules and luminal secretion. Histochemical studies indicate that the metal is bound relatively tightly within the nucleoli (associated with RNA) and in the secretory products of the cytoplasm. Changes in tissue zinc concentration, observed by other workers, following changes in various external stimuli, may not necessarily be reflected by proportionate changes in epithelial concentrations. The role of zinc in the epithelium is considered to be at least two-fold: firstly, for incorporation into vital cellular mechanisms necessary for cell maintenance and, secondly, for involvement in secretory products. It is also possible that the metal participates in the physiology of the sub-epithelial stroma.

The relationship between adrogen receptors and the hormonally controlled responses of rat ventral prostate

1. The administration of dihydrotestosterone to rats orchidectomized 7 days previously stimulated the synthesis of nuclear receptor in prostatic cells several hours in advance of DNA synthesis and mitosis. 2. The synthesis of nuclear receptor is tightly coupled to cell proliferation; consequently, in resting cells, there is no further net synthesis of nuclear receptor above the maximum of approx. 8000 molecules/cell. 3. After orchidectomy a rapid decline in the concentration of free androgen in the nuceus and a slower decline in the concentration of nuclear receptor are observed. 4. Owing to the apparent scarcity of receptor-inactivating factors in the nucleus, and the inverse relationship between amounts of nuclear and cytoplasmic receptors, it is concluded that the nuclear receptor is discharged into the cytoplasm after orchidectomy. 5. The formation of the cytoplasmic receptor is an early event preceding the onset of cellular autolysis. 6. Regressing prostate develops the capacity to eliminate cytoplasmic receptor, and this capacity is retained by the regenerating prostate for at least 14 days. 7. The synthesis of nuclear receptor in early G1 phase may control the entry of cells into the cell cycle and the prolonged retention of receptor in the nucleus may prevent the activation of autophagic processes.

Effects of an antiandrogen, cyproterone acetate, on the kidney of the three-spined stickleback (Gasterosteus aculeatus L.)

The fine structure of the kidney is studied in the sexually mature male three-spined stickleback after administration of an antiandrogen, cyproterone acetate. Under these conditions, the dedifferentiation of renal tubules is characterized by the same involutive processes as those induced by castration, with the difference that cyproterone acetate only begins to act after 14 days whereas after castration the first signs of involution are visible after 7 days. The ultrastructural modifications affect the nucleoli, the rough endoplasmic reticulum and the Golgi apparatus. They reflect an inhibition of the secretory process. The results obtained demonstrate that administration of cyproterone acetate to male sticklebacks has an inhibitory effect on renal target cells, apparently indistinguishable from the changes induced by lack of male sex hormone, and that this drug may be a valid substitute for castration in fish.

Ultrastructural modifications of renal cells in the three-spined stickleback (Gasterosteus aculeatus L.) after castration

The mechanisms of cellular autophagy have been studied in the renal epithelium of male sticklebacks (Gasterosteus aculeatus L.) following castration. Two main types of alteration are described at the level of the proximal tubule cells. At first, the formation of endoplasmic reticulum whorls is observed, followed immediately by the secretion of lacunar progranules and by nucleolar modifications. These alterations lead to a progressive decrease of the glandular activity of the cells. The other main effect of castration is a general involution of the secretory granules still present in the cells. The involutive processes which lead to the complete destruction of the secretory material and, sometimes, of entire proximal cells, are described. In the collecting tubules, a marked and rapid decrease in glandular activity occurs, followed by disappearance of the mucous secretions. Small dense granules, supposedly lysosomes, are present. The processes described also appear to be characteristic of the normal involution of the renal cells occurring at the end of the breeding period. The findings strongly suggest that the male sex hormone may exert a double control on the renal cells in the stickleback, at both the cytoplasmic and nucleolar levels.

Alterations in the fine structure of the prostate and seminal vesicle of rats treated with cyproterone acetate

Young adult male rats were treated with daily injections of 10 mg of cyproterone acetate for periods up to 16 weeks. Samples of the ventral prostate and the seminal vesicle were studied with the light and electron microscopes. Alterations visible with the light microscope included decreases in cell size, cytoplasmic basophilia, the size of the nucleolus, and the amount of luminal secretory material. Ultrastructural changes in the epithelium of both glands involved mainly the organelles that participate in the formation of secretions. Large declines were observed in the abundance of rough endoplasmic reticulum, size of the Golgi apparatus, and number of secretory vacuoles. Lipid droplets accumulated in the seminal vesicle epithelium, and lysosomes were numerous in both glands. Changes were first observed microscopically in the seminal vesicle after one week and in the prostate after two or three weeks. Maximal development of the alteration occurred after treatment for approximately eight weeks.

[Morphogenesis and significance of epithelial metaplasia in the human prostate gland. An electron-microscopic study (author's transl)]

Electron-microscopic studies were done to point out the morphogenesis of transitional and squamous epithelial metaplasia in the human prostate gland. The basis of epithelial metaplasia is a multi-layered proliferation of the basal cells and subsequent divergent differentiation. Transitional metaplasia can be viewed under the light microscope; the electron microscope on the other hand does not show all structural features of the transitional epithelium, such as: The cover cells of the metaplastic epithelium, which do not reach the basement membrane; the surface cells, which are always mononuclear and show signs of beginning adenoid differentiation. Extreme twisting of the lateral cell membranes as a morphological equivalent of deformability was not observed. Squamous epithelial metaplasia, contrary to transitional epithelial metaplasia, shows the criterions true characteristics of squamous epithelium at both the light and electron microscopic levels: The metaplastic cells have an abundant cytoplasm containing the characteristic structures with numerous tonofibrils and broad desmosomes. Microvilli-like processes of the cytoplasm project into the lacunar interfacial canals. In addition aggregates of glycogen granules and deposits of osmiophilic material can be seen, representing the first step of keratinization. Epithelial metaplasias in the prostate occur not only in the central area near the urethra, but also in the peripheral ducts and glandular acini. An estrogen-androgen imbalance is suggested to be an essential factor in the etiology of prostatic epithelial metaplasia. A reversibility of squamous epithelial metaplasia is unlikely. To our knowledge, the epithelial metaplasias in the prostate do not represent a precancerous lesion.