Prostate Of Adult Rats Research Articles

Developmental Exposure to Estrogens Alters Epithelial Cell Adhesion and Gap Junction Proteins in the Adult Rat Prostate

Developmental Exposure to Estrogens Alters Epithelial Cell Adhesion and Gap Junction Proteins in the Adult Rat Prostate

Androgen-regulated expression of a novel member of the aldo-keto reductase superfamily in regrowing rat prostate.

The rat prostate is dependent on androgen for normal growth and differentiation. In addition, the organ undergoes rapid cell death upon withdrawal of androgen on castration, and the atrophied tissue is capable of regrowth after androgen replacement in adult animals. In our search for novel factor(s) that participate in this androgen-induced proliferation of adult rat prostate cells, we have generated a complementary DNA (cDNA) library enriched in cDNAs transiently up-regulated after androgen stimulation in castrated rat ventral prostate using a PCR-based subtractive hybridization technique. Sequence analysis of about one hundred clones in the library showed that approximately 70% of them are identical or closely related to genes of known function, the remaining ones showing no or very low similarity to any genes characterized previously. Among the former a new member of the rat aldo-keto reductase superfamily that is closely related to aflatoxin, B1 aldehyde reductase has been identified. The newly identified protein (androgen-inducible aldehyde reductase, AIAR) and rat aflatoxin B1 aldehyde reductase (AFAR) exhibit 80% amino acid sequence homology. The enzymatic activity toward 4-nitrobenzaldehyde of recombinant AIAR expressed in Escherichia coli was about 16% of that of rat AFAR. Northern blot analysis revealed AIAR expression in various adult rat tissues in addition to the ventral and dorsolateral prostates, which differs from the highly restricted expression of AFAR in the kidney and liver. The AIAR messenger RNA (mRNA) content of the ventral prostate was low in normal and castrated rats, transiently increased after androgen administration to castrated rats, attaining a peak 12-24 h after the treatment. Although the physiological substrate(s) of AIAR has not been identified, the current results suggest that AIAR expression is associated with some growth-related processes in regrowing rat prostate.

Distribution of α1-adrenoceptor subtype proteins in different tissues of neonatal and adult rats

Distribution of alpha(1)-adrenoceptor (alpha(1)AR) subtype (alpha(1A), alpha(1B), alpha(1D)) proteins in brain, heart, kidney, and liver of 1-week-old rats and in brain, heart, aorta, kidney, liver, vas deferens, prostate, and adrenal glands of adult rats was investigated by Western analysis, using receptor subtype specific polyclonal antibodies. High levels of immunoreactive alpha(1A)AR and alpha(1D)AR in brain and heart and of alpha(1B)AR in liver and heart of neonatal rats were detected. In adult rat tissues, the abundance of alpha(1A)AR protein was most marked in the brain, intermediate in heart, aorta, liver, vas deferens, and adrenals, and minimal in the kidney and prostate; relative to other tissues, the expression of alpha(1B)AR was higher in brain and heart and that of alpha(1D)AR in brain. All the three receptor subtypes increased with age in the brain cortex, whereas the abundance of alpha(1B)AR increased in the heart but decreased in the liver; alpha(1A)AR and alpha(1D)AR in liver, kidney, and heart were not affected by age. It is concluded that alpha(1)AR subtypes are widely expressed in different neonatal and adult rat tissues.

Distribution of α<sub>1</sub>-adrenoceptor subtype proteins in different tissues of neonatal and adult rats

Distribution of alpha(1)-adrenoceptor (alpha(1)AR) subtype (alpha(1A), alpha(1B), alpha(1D)) proteins in brain, heart, kidney, and liver of 1-week-old rats and in brain, heart, aorta, kidney, liver, vas deferens, prostate, and adrenal glands of adult rats was investigated by Western analysis, using receptor subtype specific polyclonal antibodies. High levels of immunoreactive alpha(1A)AR and alpha(1D)AR in brain and heart and of alpha(1B)AR in liver and heart of neonatal rats were detected. In adult rat tissues, the abundance of alpha(1A)AR protein was most marked in the brain, intermediate in heart, aorta, liver, vas deferens, and adrenals, and minimal in the kidney and prostate; relative to other tissues, the expression of alpha(1B)AR was higher in brain and heart and that of alpha(1D)AR in brain. All the three receptor subtypes increased with age in the brain cortex, whereas the abundance of alpha(1B)AR increased in the heart but decreased in the liver; alpha(1A)AR and alpha(1D)AR in liver, kidney, and heart were not affected by age. It is concluded that alpha(1)AR subtypes are widely expressed in different neonatal and adult rat tissues.

Isolation and partial characterization of an epithelial cell line (RPE-F344) from the regenerating prostate of a normal adult male rat.

Normal prostate epithelial cells are difficult to propagate in vitro without experimental immortalization. The goal of this study was to isolate and characterize a propagable epithelial cell line from normal adult rat prostate. Enrichment of proliferation-competent cells was accomplished in vivo by initiating a single cycle of prostatic involution/regeneration. The RPE-F344 cell line was established from an androgen-deprived, involuted prostate four days after the initiation of regeneration by administration of testosterone. The cell line has been cultured in vitro for >50 passages, forms a uniform monolayer in culture, exhibits contact inhibition at confluence, and does not form colonies in soft agar. Immunocytochemical and RT-PCR analyses demonstrated that the RPE-F344 cells express anti-apoptotic genes associated with cell survival, and several growth factor receptors important in prostate development and homeostasis. RPE-F344 cells are p27kip1 negative, telomerase positive, and express high molecular weight cytokeratins specific for prostatic basal cells. They also express low levels of androgen receptor (AR) and prostatic acid phosphatase (PAP); features associated with secretory luminal epithelial cells. RPE-F344 cells are maintained in vitro without androgen supplementation, but addition of 15nM dihydrotesterone (DHT) to the culture media results in a significant but transient enhancement of cellular proliferation. Establishment of RPE-F344-like colonies from rat prostate is limited to the ventral and dorsal lobes of the prostate 2-4 days after initiation of regeneration, suggesting that RPE-F344 cells may originate from a stem cell-like compartment that is responsible for regenerative repopulation.

Lobe-specific telomerase activity in the intact adult brown Norway rat prostate and its regional distribution within the prostatic ducts.

It is generally established that telomerase activity is present in most cancer cells, germ line cells, and established cell lines but typically is not present in normal somatic cells. Among the few exceptions, telomerase activity has been detected in hematopoietic stem cells and in physiologically renewable epithelial cell populations (e.g. skin, small intestine). The adult rat prostate gland is a tissue that has the ability to regenerate in response to androgen. We hypothesized, therefore, that telomerase activity should be present in the normal adult rat prostate. In this study, using a highly sensitive PCR-based telomerase assay [the telomerase repeat amplification protocol (TRAP) assay], we tested this hypothesis by measuring telomerase activity in the ventral, dorsal, lateral, and anterior lobes of the adult rat prostate. We show herein that telomerase activity indeed is present in whole tissue extracts of the ventral, dorsal, and anterior lobes, though at differing levels, but not the lateral lobe. However, lateral lobe prostatic fluid was found to contain one or more factors inhibitory for the TRAP reaction, and therefore, telomerase activity was detected after removal of this fluid. Telomerase activities were not uniform within the prostatic ducts, but rather telomerase positive cells are regionally distributed within the distal, intermediate, and proximal ducts of the microdissected segments of each of the lobes. We speculate from these results that androgen-stimulated regeneration of rat prostate following androgen ablation may depend upon the telomerase-positive regenerating pool of cells present within specific regions of the ductal network.

Molecular Cloning and Expression of ps20 Growth Inhibitor: A NOVEL WAP-TYPE “FOUR-DISULFIDE CORE” DOMAIN PROTEIN EXPRESSED IN SMOOTH MUSCLE

We previously reported the purification of ps20 (Rowley, D. R., Dang, T. D., Larsen, M., Gerdes, M. J., McBride, L., and Lu, B. (1995) J. Biol. Chem. 270, 22058-22065), a urogenital sinus mesenchymal cell secreted protein having growth-inhibitory properties. We report here cloning of the 1.03-kilobase rat ps20 cDNA clone from the PS-1 (adult rat prostate smooth muscle) cDNA library. Partial clones were obtained by nested polymerase chain reaction with degenerate primers, and full-length ps20 cDNA clones were isolated by plaque hybridization. Sequence analysis revealed that ps20 protein contains a WAP-type "four-disulfide core" motif and is a novel member of the WAP signature protein family composed primarily of secreted serine protease inhibitors. Native ps20 immunoprecipitated from smooth muscle cells and recombinant ps20 both resolved on SDS-polyacrylamide gel electrophoresis with apparent molecular mass of 27-29 kDa under reducing conditions and 21-23 kDa under non-reducing conditions, respectively. Stable ps20-transfectant COS-7 cell lines secreted ps20 and were growth-inhibited relative to mock transfectants. In addition, COS-7 and prostate carcinoma PC-3 cells were growth-inhibited by bacterially expressed ps20. Northern analysis indicated differential expression by tissue with highest expression in the heart. Immunohistochemical localization of ps20 protein showed cell-specific expression by both visceral and vascular smooth muscle in all tissues, including the prostate gland. These results indicate ps20 is a novel growth-regulatory member of the WAP signature family expressed by smooth muscle cells.

Neonatal Estrogen Exposure Up-Regulates Estrogen Receptor Expression in the Developing and Adult Rat Prostate Lobes*

Neonatal exposure to estrogens results in permanent imprints of the rat prostate gland. To delineate the direct target of estrogen action within that tissue, the present study examined estrogen receptor (ER) expression by immunocytochemistry and in situ hybridization. ER were confined to mesenchymal cells in the urogenital sinus and proximal regions of the budding prostate lobes of newborn control rat prostates, and this expression declined after morphogenesis. Exposure to estradiol benzoate on days 1, 3, and 5 resulted in induction of ER expression in periductal smooth muscle cells from the proximal regions out to the distal tips of the developing prostate lobes. This ER expression was associated with the appearance of ER messenger RNA in those cells; thus, it was concluded that the up-regulation of ER by estrogens is mediated at the message level. Autoregulation of ER expression was next examined in adult prostates that had been exposed to oil or estrogens neonatally. Day 70 rats were castrated and given testosterone with or without estradiol for 7 days before death. Estrogen exposure in adulthood induced low levels of epithelial cell ER in the lateral lobe. Neonatal estrogenization increased the sensitivity of lateral lobe epithelial cells to this autoregulation, as the incidence and intensity of ER immunostaining were markedly increased. No autoinduction of ER was observed in adult ventral or dorsal prostatic lobes. From the present study we conclude that smooth muscle cells are the targets of estrogen action in the developmentally estrogenized prostate and that estrogen amplifies its own effects through auto-up-regulation of ER. In addition, lateral lobe epithelial cells are sensitive to estrogen up-regulation of ER, which may in part account for the lobe-specific effects observed after neonatal estrogenization of the prostate gland.

Neonatal Estrogen Exposure Up-Regulates Estrogen Receptor Expression in the Developing and Adult Rat Prostate Lobes

Neonatal Estrogen Exposure Up-Regulates Estrogen Receptor Expression in the Developing and Adult Rat Prostate Lobes

Autoregulation of androgen receptor in rat ventral prostate: involvement of c-fos as a negative regulator

Recent work from our laboratory has focused on elucidating the mechanism of androgen regulation of the androgen receptor (AR). We have demonstrated that testosterone increases AR protein and binding within 1 h in the ventral prostate of adult rats castrated for 24 h. Cycloheximide administered with testosterone reduces AR and AR mRNA levels. AP-1/c-fos transcription factor has been shown to function as a negative repressor in many systems. c-fos mRNA levels were decreased 1 h after testosterone treatment in the ventral prostate, whereas they were increased in cycloheximide alone or cycloheximide-testosterone treated groups as compared to vehicle control. c-fos protein was also increased in the testosterone-cycloheximide treated group as compared to testosterone alone or cycloheximide alone groups at 1 h. By 3 h, the tissue recovers from the inhibitory effect of cycloheximide as evidenced by restoration of AR and an increase in AR mRNA levels. At this time c-fos protein levels were reduced after treatment with cycloheximide and testosterone and c-fos mRNA levels were comparable to the controls. These results suggest that elevation of c-fos expression is associated with a decrease in AR and AR mRNA and provide correlative data supporting negative repression by c-fos on androgen receptor levels. Between the age of 25–85 days, serum testosterone levels reached adult levels by the age of 55 days. Steady-state AR mRNA levels increased significantly by the age of 85 days while c-fos mRNA levels remained at low baseline levels at all ages. Thus, in addition to the circulating levels of serum testosterone, other age related factors are also involved in the regulation of AR mRNA levels. Furthermore, androgens appear to maintain androgen receptor levels and androgen sensitivity by continuous suppression of the repressor. c-fos.

Influence of testosterone on chondroitin sulphate proteoglycan in the rat prostate.

There are recognized interactions between prostatic stromal and epithelial cells. These interactions may be influenced by the composition of the extracellular matrix, which is composed of proteins such as collagen, laminin, fibronectin, and proteoglycans (PGs) such as chondroitin sulphate proteoglycan (CSPG). In our continuing studies on prostate biology, we examined the three lobes of the normal adult rat prostate, i.e., ventral, dorsal, and lateral, for CSPG by indirect immunofluorescence, using an immunospecific monoclonal antibody (CS-56) for the chondroitin sulphate (CS) moiety of the PG. Staining of the prostate sections with CS-56 antibody followed by labelling with IgG fluorescein isothiocyanate conjugate indicated strong fluorescent signals associated with the ventral lobe basement membrane. The signal was stronger and more continuous in the distal acini than in the proximal acini. The staining of the dorsal and lateral lobes was less intense than that of the ventral lobe. Following castration of the rats, the basement membrane staining became discontinuous. Androgen replacement by administration of testosterone propionate (TP) reversed the effects of castration. Quantification of the total CS content showed decreases of about 60% in the ventral and lateral lobes after castration. TP administration for 14 days increased the total CS content several fold above the values for castrated rats in all lobes. The results demonstrated that CS content was significantly higher for TP-treated animals, suggesting that the expression of prostate CSPG is regulated by androgens. This approach should be useful in the study of the extracellular matrix in prostate biology.

An edgewise look at basal epithelial cells: Three-dimensional views of the rat prostate, mammary gland and salivary gland

Wholemount immunocytochemical staining was used to visualize basal and luminal epithelial-cell-specific cytokeratin and smooth muscle α-actin expression in the developing and adult rat prostate, in the pregnant rat mammary gland and adult rat salivary gland. The stained samples were examined using an Edge R400 3D microscope. Images were collected in both single-image and stereo-pair formats. Prostatic basal epithelial cells were found to have a cell body covering an area of 52–62 μm 2. The mean footprint size of basal cells was not significantly different between prostatic lobes. Basal epithelial cells were most dense in the anterior and most sparse in the ventral prostatic lobes. Basal epithelial cells had a large body with many processes, which spread around the duct and projected between luminal cells towards the lumen. These processes closely approached their counterparts from adjacent basal cells. In the developing prostate the differentiation of the basal cells from undifferentiated epithelial cords was observed at the region of ductal widening associated with canalization. Following castration prostatic basal epithelial cells became more closely packed, though the size of individual cells was not significantly changed. There was a two-to four-fold increase in basal cell density by 7 days after surgery. Most prostatic luminal cells were found to have hexagonal bases though some were pentagonal in shape. Luminal cells had a mean basal area of 50 μm 2. In the prostate immunocytochemical staining against smooth muscle α-actin revealed discrete bands of muscle surrounding individual prostatic ducts. In the mammary and salivary glands the epithelium was organized into an alveolar arrangement. In the salivary gland a single basal epithelial cell covered the top of each alveolus with processes arranged down the side of the structure. In the mammary gland several basal cells were draped over each alveolus. The mammary and salivary gland basal cells expressed smooth muscle α-actin, indicating their myoepithelial phenotype. The organization of the mammary and salivary gland basal cells placed them in an ideal position to squeeze the alveolar structures.

Androgenic induction of cystatin-related protein and the C3 component of prostatic binding protein in primary cultures from the rat lacrimal gland

Cystatin-related protein (CRP) and the C3 component of prostatic binding protein (C3) are synthesized in vivo under androgen control in the lacrimal gland and ventral prostate of adult male rats [1,2]. Androgen administration to female or 7-day castrated male rats, which do not express CRP, can induce its synthesis [3]. In this study, we show androgen-dependent expression of CRP1 and C3 in primary cultures of acinar cells of the lacrimal gland of female rats. Addition of androgens to the culture medium results in the synthesis and secretion of both proteins in a time- and dose-dependent way. Estradiol or progesterone are unable to induce their expression. Dexamethasone in low concentrations and present as a basal component of the serum free defined medium, is needed to sensitize the culture system for androgens. In high concentrations, this synthetic glucocorticoid seems to play a similar role as androgens in CRP1 and C3 regulation.

Androgen Receptor in the Rat Pancreas

Androgens influence the incidence and prevalence of pancreatic cancer in humans and animal models. To our knowledge there has been molecular demonstration of the presence of neither the androgen receptor (AR) nor transcripts of the AR gene. Reverse-transcription polymerase chain reaction (RT-PCR)-Southern blotting was employed for molecular detection and measurement of the androgen receptor messenger ribonucleic acid (AR mRNA) in pancreas. Total RNA obtained from pancreas, prostate, seminal vesicles, and testes of neonatal and adult male and female rats, as well as castrated males substituted with testosterone cyclopentylate, was analyzed by Northern blot technique. Positive hybridization to AR cDNA was obtained in all tissues assayed but not in the pancreas. However, a clear AR 32P cDNA hybridization signal was obtained in pancreatic tissues after cDNA synthesis using RT-PCR-Southern blotting. The levels of the AR transcripts obtained by RT-PCR in the various pancreatic samples were as follows: adult females and neonatal animals > castrated adult males > adult males > castrated adult males substituted with testosterone. These results indicated that the pancreatic tissue possessed transcriptional activity of the AR gene, although to a lesser extent than the typical androgen responsive tissues (prostate and seminal vesicles). In conclusion, transcriptional activity of the AR gene in the pancreas seemed to be modulated by the androgenic milieu in the tissue similar to that reported for the classical androgen-responsive organs.

Instructive induction of prostate growth and differentiation by a defined urogenital sinus mesenchyme.

Instructive influences of fetal mesenchyme were examined in heterotypic tissue recombinants consisting of urogenital sinus mesenchyme (UGM) from male and female rats and distal ductal tips from adult rat prostate. Tissues were grown under the renal capsule of male hosts for periods up to 28 days. Resultant growths exhibited typical prostate histology. Expression of lobe-specific proteins for the ventral (prostatic steroid binding protein [PSBP]) lateral (seminal vesicle secretion II [SVS II]), and dorsal prostate (secretory transglutaminase [TGase]) were examined by immunocytochemistry. Male or female UGM combined with terminal segments of the ventral or dorsal prostate and immunolabeled with antibodies to lobe-specific proteins demonstrated expression of all three secretory products. The pattern of staining was consistent with a compound inductive response from the UGM. Unique to this study was our ability to use a defined mesenchymal tissue (female ventral mesenchymal pad [VMP]). This tissue is specifically associated with ductal branching morphogenesis and cytodifferentiation of the ventral prostate. Distal ductal tips from the dorsal lobe of the adult male prostate when recombined with female VMP and grown in vivo exhibited transformation of secretory phenotype, and the epithelium expressed mRNAs for PSBP. Immunocytochemistry of serial sections did not demonstrate labeling for TGase in the new epithelial growth. Ultrastructural analysis of the heterotypic recombinants indicated that the epithelium had similar characteristics to those of normal ventral prostate. Early stages of the mesenchymal-epithelial interactions resulted in dedifferentiation of the adult epithelium to solid cords of stratified cells. These findings illustrate the potent instructive capacity of a defined fetal UGM to influence development and cytodifferentiation of adult prostate epithelium.

Effects of castration on apoptosis and transforming growth factor-beta 1 mRNA in the neonatal mouse seminal vesicles

In the adult male rat prostate, castration induces apoptosis of epithelial cells concomitant with the increase in transforming growth factor-beta 1 (TGF-beta 1). In the present study, we investigated the effects of castration on apoptosis and TGF-beta 1 mRNA in neonatal mouse seminal vesicles. 5-day-old BALB/c mice were castrated by Pfeifer's method. We estimated the weight, 3H-thymidine uptake by whole seminal vesicles, the amount of TGF-beta 1 mRNA by RT-PCR method, and the apoptotic index of both epithelium and mesenchyme. The castration of 5-day-old neonatal mice resulted in much less weight of seminal vesicles and DNA synthesis estimated by 3H-thymidine uptake by whole seminal vesicles compared to intact neonatal mice, indicating that the growth of neonatal mouse seminal vesicles depends on androgens secreted by the testis. The amount of TGF-beta 1 mRNA estimated by RT-PCR method increased 4 days after castration at 5 days of age. However, the castration did not induce apoptosis in the seminal vesicles. The present study indicates that castration of neonatal mice does not induce apoptosis in the seminal vesicles, although it does a transient increase in TGF-beta 1 mRNA in the seminal vesicles.

An orthotopic model for the study of growth factors in the ventral prostate of the rat: effects of epidermal growth factor and basic fibroblast growth factor.

In order to determine if epidermal growth factor (EGF) or basic fibroblast growth factor (bFGF) are capable of stimulating prostatic growth in situ, we complexed EGF and bFGF to a Matrigel (MG) vehicle that was subsequently injected orthotopically into the ventral prostate of adult rats. Three weeks following a single injection of 0.1 ng of EGF or bFGF, the wet weight of the growth factor-injected lobes of the ventral prostate was increased (P < or = 0.025) 144 +/- 14% and 138 +/- 8%, respectively compared to contralateral lobes injected with MG only. Total DNA and protein per lobe (P < or = 0.025) and the incorporation of bromodeoxyuridini (BrdUrd; P < or 0.01) were all significantly increased in lobes injected with EGF or bFGF compared to MG-injected lobes. Thus, EGF and bFGF were stimulating true growth of the rat ventral prostate in situ. The induced prostatic growth was ligand specific, because co-injection with neutralizing antibodies abolished EGF and bFGF stimulation of prostatic wet weight. The effect of a single injection of 0.1 ng of growth factor was long-lasting and elevated prostatic wet weight for 4 (P < or = 0.05; bFGF) to 6 (P < or = 0.05; EGF) weeks. Histologic evaluation did not reveal any gross changes in the ratio of stroma to epithelium in either EGF- or bFGF-injected lobes at the 0.1 ng/lobe dose. A slight hyperplasia of the prostatic epithelium was detected in lobes injected with 10 ng of EGF. Of note, the incorporation of BrdUrd was primarily localized in the luminal and basal epithelial cells, whereas incorporation into the prostatic stroma was scanty in lobes injected with either EGF or bFGF. In summary, we have developed an orthotopic model enabling the study of the roles of growth factors in prostatic physiology, function, and disease in situ. Additionally, we have demonstrated that when injected orthotopically into the rat ventral prostate, EGF and bFGF stimulate the growth of the prostatic epithelium to similar degrees.

Antiandrogenic activity and endocrinological profile of a novel antiandrogen, TZP-4238, in the rat.

TZP-4238 is a new potent, orally active steroidal antiandrogen. Antiandrogenic activity and endocrinological profile of TZP-4238 were investigated in rats, except that progestational activity was determined in rabbits. TZP-4238 suppressed the testosterone propionate-induced increases in the weights of the ventral prostate, seminal vesicle and levator ani in castrated immature male rats. TZP-4238 also decreased the weights of the ventral prostate, seminal vesicle and levator ani in intact adult male rats, but did not affect the weight of the testis or the serum concentrations of luteinizing hormone and testosterone. TZP-4238 did not have such an inhibitory effect on the weight of the adrenal gland as seen in other steroidal antiandrogens. It exhibited potent progestational activity. Although TZP-4238 did not exert androgenic or estrogenic activity, it had weak antiestrogenic activity. These results suggest that TZP-4238 exerts an antiandrogenic effect on the prostate without any compensatory change in the serum concentration of luteinizing hormone or testosterone in rats, and it is a useful drug for the treatment of androgen-dependent diseases such as prostatic hypertrophy and prostatic cancer.

The Golgi apparatus and acid phosphatase-negative cisternal portions of the trans-Golgi network: ultrastructural and cytochemical studies of secretory epithelial cells in the rat lateral prostate.

Ultrastructural and enzyme-cytochemical studies were performed on the Golgi apparatus in secretory cells of the lateral prostate of normal adult rats using serial ultra-thin sections. In the trans-Golgi area, a unique membrane complex composed of tubular portions and cisternal portions showing a rigid appearance is found. This corresponds to the GERL (Novikoff 1964) or the trans-Golgi network (Griffiths and Simons 1986). From their structural similarities, the cisternal portion found in this study is considered to be the same structure as the plate-like cisterna reported by Inoue and Kurosumi (1989). As we reported previously (Kimura and Ichihara 1985), there are at least two types of acid phosphatase (AcPase) in secretory cells of the rat lateral prostate: one is located only in the structural components involved in their secretory functions and reacts readily with naphthol AS-BI phosphate; the other is a lysosomal type, which reacts well with beta-glycerophosphate. Lysosomal AcPase activity demonstrated by Gomori's method (1952) was found in a few middle- to trans-Golgi cisternae and in lysosomes. The AcPase detectable with Gomori's method and thiamine pyrophosphatase seemed to exist in part in the same cisterna on the trans side. With Robinson and Karnovsky's method (1983) for lysosomal AcPase, however, the reaction products were found only in lysosomes that were occasionally tubular in shape. On the other hand, any activity of AcPases tested could not be detected in the cisternal portion with the rigid appearance. Thus, in secretory cells of the adult rat lateral prostate in normal condition, it is considered that the cisternal portion of GERL, or the trans-Golgi network, has no relation to the processing and/or transport of AcPases.

Localization of the glucocorticoid receptor in testis and accessory sexual organs of male rat

Localization of glucocorticoid receptor-like immunoreactivity (GR-LI) was studied in adult rat testis, epididymis, ejaculatory duct, seminal vesicle and prostate by light and electron microscopic immunocytochemistry. In the interstitium of the testis GR-LI was seen in the nuclei of Leydig cells, macrophages, fibroblasts, smooth muscle cells and endothelial cells of blood vessels. Furthermore, GR-LI was observed in zygotene and early pachytene primary spermatocytes of some seminiferous tubules during stages XIII–XIV and I–III of the spermatogenic cycle. Other spermatogenic cells and Sertoli cells were devoid of staining. GR-LI was also found in peritubular myoid cells, fibroblasts and basal cells of the epididymis, vas deferens and prostate. Localization of GR-LI in primary spermatocytes and Leydig cells suggests that glucocorticoids directly affect spermato- and Steroidogenesis in the testis. The absence of GR-LI from functional, stromal cells of the male accessory sexual organs suggests that they are not targets for glucocorticoid hormones.