Normal Rat Ventral Prostate Research Articles

Expression of gonadotropin‐releasing hormone receptor mRNA in the rat ventral prostate and Dunning R3327 PAP adenocarcinoma before and after castration

BACKGROUND Continuous administration of gonadotropin-releasing hormone (GnRH) agonists in prostate cancer patients results in involution of the tumors due to suppression of androgen production. In addition to the effect of GnRH at the hypothalamic-pituitary level, experiments in vitro on breast, ovary, and prostatic cells have shown an inhibition of cell proliferation, indicating the presence of local GnRH receptors (GnRH-R). The aim of the present study was to investigate the expression of GnRH-R mRNA in the normal rat ventral prostate (VP) and Dunning R3327 PAP adenocarcinoma and to evaluate the effects of castration on receptor mRNA expression. METHODS RNA was prepared from ovaries, pituitaries, VP, and Dunning tumors from both intact and castrated animals. GnRH-R mRNA levels were quantified by a competitive reverse transcription-polymerase chain reaction (RT-PCR) method. RESULTS GnRH-R mRNA was detected in normal VP and Dunning tumors. Normal VP showed lower amounts of GnRH-R mRNA compared to Dunning tumors. An elevation of mRNA expression was observed 7 days after castration in Dunning tumors. CONCLUSIONS GnRH-R mRNA was found in both VP and Dunning tumors, indicating the presence of a local GnRH system. Normal VP showed lower amounts of GnRH-R mRNA when compared to malignant tissues. GnRH-R mRNA levels were elevated in Dunning tumors following castration. Prostate 39:101–107, 1999. © 1999 Wiley-Liss, Inc.

Expression of gonadotropin-releasing hormone receptor mRNA in the rat ventral prostate and dunning R3327 PAP adenocarcinoma before and after castration.

Continuous administration of gonadotropin-releasing hormone (GnRH) agonists in prostate cancer patients results in involution of the tumors due to suppression of androgen production. In addition to the effect of GnRH at the hypothalamic-pituitary level, experiments in vitro on breast, ovary, and prostatic cells have shown an inhibition of cell proliferation, indicating the presence of local GnRH receptors (GnRH-R). The aim of the present study was to investigate the expression of GnRH-R mRNA in the normal rat ventral prostate (VP) and Dunning R3327 PAP adenocarcinoma and to evaluate the effects of castration on receptor mRNA expression. RNA was prepared from ovaries, pituitaries, VP, and Dunning tumors from both intact and castrated animals. GnRH-R mRNA levels were quantified by a competitive reverse transcription-polymerase chain reaction (RT-PCR) method. GnRH-R mRNA was detected in normal VP and Dunning tumors. Normal VP showed lower amounts of GnRH-R mRNA compared to Dunning tumors. An elevation of mRNA expression was observed 7 days after castration in Dunning tumors. GnRH-R mRNA was found in both VP and Dunning tumors, indicating the presence of a local GnRH system. Normal VP showed lower amounts of GnRH-R mRNA when compared to malignant tissues. GnRH-R mRNA levels were elevated in Dunning tumors following castration.

CRYOSURGICAL ABLATION OF THE NORMAL VENTRAL PROSTATE PLUS ADJUVANT DOES NOT PROTECT COPENHAGEN RATS FROM DUNNING PROSTATIC ADENOCARCINOMA CHALLENGE

We wished to determine if cryosurgical ablation of the normal ventral prostate of Copenhagen rats confers protective immunity against a subsequent challenge with Dunning R3327 MatLyLu prostatic adenocarcinoma. In human melanoma, tumor antigens have been characterized as normal cellular proteins. We reasoned that cryosurgical ablation of the normal prostate along with immunostimulatory adjuvants might release prostatic antigens to the immune system engendering an immune response and rendering rats immune to prostatic cancer cells. On day 0, Copenhagen rats underwent cryosurgical ablation of the normal ventral prostate, cryosurgery and intraprostatic injection of Complete Freund's Adjuvant (CFA), CFA injection alone, or laparotomy alone. On day 21, animals received a subcutaneous challenge of MatLyLu tumor cells. Tumor dimensions were recorded at regular intervals by a single blinded investigator. Animals receiving cryosurgical ablation of the normal ventral prostate or intraprostatic CFA developed tumors more frequently than animals receiving laparotomy alone and the effect was statistically significant if animals received both cryosurgical ablation of the prostate and intraprostatic CFA (3 experiments, 1 x 10(4) MatLyLu cells), total number with tumors/total number challenged: laparotomy alone 3/17, cryosurgical ablation 7/17, cryosurgery plus CFA 10/16 (p = 0.013 versus laparotomy, Fisher's exact test), CFA alone 9/17. Cryosurgical ablation of the normal rat ventral prostate and intraprostatic CFA does not protect against and can enhance the tumorigenicity of MatLyLu prostatic cancer cells at distant sites. This could be occurring through specific immunologic effects or non-specific mechanisms induced by cryosurgery and CFA.

Expression and degradation of rat androgen receptor following castration, testosterone replacement and antiandrogens administration: analysis by Western blot and immunohistochemistry.

To elucidate the autoregulation of androgen receptor (AR) by androgen and antiandrogen, Western blot analysis and immunohistochemical study were performed. Castration reduced the immunodetected AR content, and nuclear staining was lost without cytoplasmic staining. Testosterone (T) supplement restored AR content. Quick response of AR content restoring following single administration of T was observed 48 hours after castration. The recovery of AR content detected by Western blot under each condition was accompanied by recovery of the reduced unclear staining intensities in the epithelia. Neither steroidal nor non-steroidal antiandrogens, chlormadinone acetate and flutamide, altered the AR content in normal rat ventral prostate 5, 12, 24 or 48 hours after single administration. Furthermore, neither of the drugs at various doses altered AR levels 12 hours after single administration. In summary, the rat AR is upregulated by androgen. Single administration of antiandrogens have no effect on immunodetected AR content.

Matrilysin expression in the involuting rat ventral prostate.

Matrilysin (PUMP-1) is a member of the matrix metalloproteinase (MMP) family of extracellular matrix degrading enzymes that has been found to be overexpressed in human prostate cancer. The rat ventral prostate (RVP) following castration has been used as a model for both tissue involution and apoptosis. Northern analysis and in situ hybridization were used to determine the time course and localization of matrilysin during 8 days of RVP involution. Northern analysis revealed that the 1.2 kb matrilysin mRNA was undetectable in normal RVP. An increase in the steady-state levels of matrilysin mRNA was observed 5 days after castration, and the levels began to decline by 8 days after castration. The mRNAs for tissue inhibitor of metalloproteinase-1 and urokinase-type plasminogen activator also showed a time-dependent induction during the course of involution. Localization of matrilysin by in situ hybridization indicated that the mRNA was produced by epithelial cells of the involuting RVP. The matrilysin message was observed in a small number of glands within the whole RVP. Matrilysin protein was present in the RVP and peaked 3 days after castration. The combination of proteinase genes expressed in the RVP following castration indicate that the MMP and serine protease families of enzymes may interact during tissue remodeling of the RVP following castration.

TRPM-2 gene expression in normal rat ventral prostate following castration and exposure to diethylstilbestrol, flutamide, MK-906 (finasteride), and coumarin.

TRPM-2, not normally expressed in the rat ventral prostate, has been identified as an important genetic marker of castration-induced apoptotic cell death. It is not known whether other agents capable of causing growth inhibition of the rat ventral prostate also induce TRPM-2 expression. To investigate this further, 270 mature Sprague-Dawley rats were randomized into one of six groups: control, castration, diethylstilbestrol (DES), flutamide, MK-906 (finasteride), or coumarin. Five rats per group were sacrificed on days 1, 3, 5, 7, 10, and 21. Serum testosterone, body weights, and prostate weights were determined at each time point. The ventral prostate was removed and cellular RNA extracted. Northern blot analysis using cDNA probes for TRPM-2 and gamma-actin were performed at each time point. Only DES significantly decreased rat weights. DES and castration reduced serum testosterone to undetectable levels by the next day. Flutamide caused a 3.0- to 4.5-fold increase in serum testosterone above control. Coumarin and MK-906 did not affect serum testosterone levels. DES and castration reduced prostate weights to 20% and 6% of control, respectively, while inducing TRPM-2 expression to a maximum on day 5 of the experiment. DES induced TRPM-2 expression over a longer duration than did castration, suggesting that more than just the decrease of serum testosterone to castrate levels plays a role in the expression of TRPM-2. MK-906, coumarin, and flutamide reduced prostatic weights to a lesser extent (50%, 63%, 71% of control, respectively), but these agents did not induce TRPM-2 expression at any time during the experiment. TRPM-2 expression in the rat ventral prostate does not correlate simply with catabolic effects on the prostate.

Expression of bone morphogenetic protein messenger RNAs by normal rat and human prostate and prostate cancer cells

Human prostate cancer cells are known to produce several growth regulatory factors, including transforming growth factor beta (TGF beta) and heparin-binding fibroblast growth factors (FGFs), which may play as-yet-undefined roles in prostate gland morphogenesis, as well as in prostate cancer cell behavior. Recently, a family of proteins in the extended TGF beta family, the bone morphogenetic proteins (BMPs), has been identified which stimulates bone formation in vivo, and in which, the proteins are likely involved in a variety of morphogenetic processes during embryogenesis. These powerful morphogenetic factors are capable of redirecting muscle mesenchyme cells to differentiate along the lines of bone tissue. We examined a number of well-characterized rat and human prostate cancer cell lines for the expression of BMP 2, 3, 4, and 6 messenger RNA. Poly(A+)-RNA was isolated from normal human and rat ventral prostate, from the rat prostate adenocarcinoma PAIII tumor and cultured cells derived from it, and from human prostate cancer cell lines PC-3, LNCaP, and DU-145. BMP mRNA levels were measured using BMP 2, 3, 4 and Vgr-1 (BMP 6) cDNA probes. Both normal and neoplastic prostate tissue expressed these BMP mRNAs, although the level of expression varied from tumor to tumor. Normal human prostate expressed BMP 4 mRNA predominantly, as did the human prostate cancers PC-3 and DU-145. PC-3 also expressed BMP 2 mRNA and BMP 3 mRNA in large amounts. Normal rat ventral prostate expressed all these BMP mRNAs, but the rat prostate adenocarcinoma PAIII expressed predominantly BMP 3 mRNA. The reason that different BMPs are expressed in varying amounts by these normal and neoplastic cells is unknown. However, if these BMPs are expressed in biologically active form, they could be responsible for important effects on normal prostate growth and morphogenesis, on neoplastic prostate cell behavior, and could even contribute to the capacity of prostatic cancer cells to stimulate new bone formation at metastatic tumor sites in bone.

Luteinizing hormone-releasing hormone (LHRH) in rat prostate: characterization of LHRH peptide, messenger ribonucleic acid expression, and molecular processing of LHRH in intact and castrated male rats.

Continuous administration of LHRH agonist suppresses the pituitary-gonadal axis, achieving chemical castration. Thus, LHRH agonist has been used as an alternative (to surgical castration) for the treatment of steroid-dependent prostate cancer. However, recent reports have demonstrated that LHRH agonist had a direct inhibiting effect on prostate cancer cell proliferation and that cancerous prostate tissue contained a LHRH-like peptide. In this paper we are reporting for the first time that the normal rat ventral prostate contained immunoactive and bioactive LHRH as well as its precursor molecule, pro-LHRH. Our investigation showed that the LHRH concentration in prostate increased 2 weeks after castration from 1.68 +/- 0.09 to 3 +/- 0.2 pg/mg tissue (P < 0.001). At the same time, the concentration of pro-LHRH decreased from 149 +/- 6.5 to 68 +/- 6.8 pg/mg tissue (P < 0.001). Furthermore, intact rat prostate expressed LHRH mRNA, which increased 13-fold 2 weeks after castration. In summary, the prostate of intact Sprague-Dawley rats has the capacity to produce the LHRH precursor and process it to the mature decapeptide, and this production/processing increases significantly after castration.

Alterations in mRNA levels for growth-related genes after transplantation into castrated hosts in oncogene-induced clonal mouse prostate carcinoma.

A clonal mouse prostate carcinoma was established by the introduction of the ras and myc oncogenes via the recombinant retrovirus Zipras/myc 9 using a mouse prostate reconstitution model system. A single-cell suspension derived from an early passage ras+myc-induced carcinoma was inoculated into the flanks of intact or castrated adult male C57BL/6 mice, and tumors were harvested 3 wk postinoculation for northern and Southern blotting. Tumor volume analysis showed that this carcinoma was not dependent on testicular androgens for growth. Southern blot analysis of virus-cell DNA junction fragments revealed that tumor cell populations recovered from both intact and castrated mice were progeny of the same virus-infected cell. Northern blotting showed that mRNA levels for the four growth-related genes transforming growth factor-beta 1 (TGF-beta 1), transforming growth factor-beta 3 (TGF-beta 3), tissue-type plasminogen activator (tPA), and c-myc were significantly elevated in clonal mouse prostate carcinomas grown in castrated hosts. In contrast, androgen receptor mRNA levels were significantly reduced under the same conditions. The response of TGF-beta 1, tPA, and c-myc mRNA levels in the carcinomas grown in castrated hosts was similar to that shown previously in normal rat ventral prostate. However, unlike normal rat ventral prostate after castration, increased numbers of apoptotic cells were not seen in the castrated group relative to the intact group at the time of analysis, indicating that the altered gene expression was not associated with cell death. In addition, testosterone-repressed prostate mRNA number 2 levels, shown previously to be elevated after castration in normal rat ventral prostate, were not increased in the androgen-deprived clonal mouse prostate carcinomas. Therefore, this early passage clonal ras+myc-induced prostate carcinoma demonstrates unique patterns of expression for a set of growth-related genes in an androgen-deprived environment.

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.

Differential effects of growth factor antagonists on neoplastic and normal prostatic cells

Growth factors such as epidermal growth factor and fibroblast growth factor have been suggested to be involved as paracrine or autocrine mediators of androgen action in normal and malignant prostatic cells. Suramin and protamine are potent in vitro growth factor antagonists. To evaluate the effect of growth factor antagonists on prostatic growth, suramin and protamine were administered to castrated rats simultaneously receiving exogenous testosterone replacement in an attempt to block androgen-dependent restoration of the normal rat ventral prostate. Using this prostatic restoration model, there was no statistical difference in the prostate wet weight or total DNA content attained between rats given testosterone alone and those given testosterone in combination with either suramin or protamine. In intact rats, suramin administration caused an 80% reduction in serum testosterone; concomitantly, these rats had a 40% reduction in mean prostate weight. This decrease in size could be blocked with androgen supplementation. To examine the effects of growth factor antagonists on neoplastic prostatic cell growth, rats bearing the androgen-independent AT-2 subline of the Dunning R-3327 tumor were treated with either suramin or protamine. The same dosing regimen found to be ineffective in blocking the restoration of the involuted prostate of castrated rats resulted in a significant reduction in the growth rate of AT-2 tumors. These results suggest that the growth factor antagonists suramin and protamine given in vivo have a differential ability to slow the growth of malignant vs. normal prostatic cells.

Distribution of glycoconjugates in normal rat ventral prostate and their use as markers of androgen-controlled secretory function in culture.

The distribution of glycoconjugates in uncultured and cultured rat ventral prostate was studied by using eight fluorescent lectins. The prostate pieces were cultured in defined medium with or without testosterone for 1-14 days. Each lectin revealed a characteristic binding pattern. Con A, LCA, WGA, and RCA I stained both epithelial and interstitial components. SBA and PNA were specific for the epithelium: SBA stained the region of the Golgi complex; PNA showed the brightest fluorescence in the apical part of the cells representing the region of secretory granules. In culture without testosterone the epithelial cells gradually lost their fluorescence, whereas the stromal fluorescence increased. The basement membrane was disorganized. With testosterone the integrity of the epithelium and stroma was maintained, and the staining pattern of the lectins was in the main similar as in vivo. However, at 14 days a change in the staining pattern of apical cytoplasm with PNA was noted, indicating that in long-term cultures, in addition to testosterone, other hormones and growth factors are necessary to complete especially the last stages of the secretory process in the epithelial cells.

Proliferative responses of normal rat ventral prostate in organ culture: Effects of testosterone and its metabolites in chemically defined medium

AbstractProliferative responses of normal rat ventral prostate to testosterone were compared with that of its major metabolites, 5α‐dihydrotestosterone, androstenedione, androstanedione, and 5α‐androstane‐3β,17β‐diol in serum‐free organ culture medium using the incorporation of 5‐[125I]‐iodo‐2′‐deoxyuridine (125I‐UdR) to monitor DNA synthesis. With the exception of 5α‐androstane‐3β,17β‐diol, these androgens induced comparable increases in DNA synthesis at both 4 × 10−9 and 4 × 10−7 M, and at 4 × 10−5 M they exerted a nonspecific cytotoxic effect, resulting in marked suppression of 125I‐UdR uptake. In contrast, 5α‐androstane‐3β,17β‐diol was not stimulatory at 4 × 10−9 M, whereas at both 4 × 10−7 and 4 × 10−5 M it stimulated marginal increases in DNA synthesis and effectively maintained the histology of the tissue in a state comparable to the intact gland. Unlike 5α‐dihydrotestosterone, its epimer 5β‐dihydrotestosterone was inactive at all concentrations used. These results support the hypothesis that testosterone action in the prostate is mediated by the formation of active 5α‐reduced metabolites.

Characteristics of Separated Epithelial and Stromal Subfractions of Prostate: I. Rat Ventral Prostate

These studies were initiated with the objective of isolating epithelial and stromal cells of human prostatic tissue in undamaged state, in order to study the cellular distribution of steroid receptors in benign prostatic hyperplasia (BPH) relative to normal prostate. Initial experiments showed that when BPH tissue immersed in tissue culture media was progressively fragmented by various cutting procedures, epithelial elements were selectively released as clumps of variable size and individual cells, but that a large percentage of these cells were damaged, as evidenced by their failure to exclude trypan blue (TB). These observations suggested that if tissue framentation were carried out under defined conditions that minimize cell damage, BPH subfractions might be obtained containing a large percentage of undamaged cells. To determine conditions of tissue fragmentation which result in maximal recovery of epithelial cells which exclude TB, rat ventral prostate (RVP) was chosen as a model system. Experiments with RVP revealed that maximal yields of such cells were obtained in “large” epithelial clumps (>30 cells per clump) released under the following conditions: (1) chopping the tissue with razor blades in a large volume (2 ml/100 mg RVP) of a Ca2+-free tissue culture medium (Joklik's-MEM) containing 1% casein, (2) carrying out the entire fractionation procedure in the cold, and (3) maintaining a 1% casein concentration in the medium during chopping, as well as in subsequent washing procedures, to protect cells from proteolytic activity. In large epithelial clumps, cells in the interior of the clump were not stained by TB but the cells at the periphery of the clump were freely permeable to TB. Single epithelial cells and small epithelial clumps (3–10 cells) released by razor blade fragmentation were also permeable to TB. When large epithelial clumps were incubated at 20°C for 90 min, the clumps disaggregated into smaller clumps and morphologically intact single cells, which did not exclude TB. The residual tissue fragments remaining after chopping contained the bulk of stromal cells plus some epithelial elements. The latter could be removed by gentle rubbing of the fragments on a sieve in the presence of medium. The stromal fraction thus obtained consisted of stromal cells, embedded in mesenchymal matrix, which were not stained by TB and appeared normal when examined histologically by light microscopy. The androgen receptor content per unit DNA (AR/DNA) of epithelial clumps and stromal fractions from castrate (1 day) and normal intact rats were compared to control RVP (coarsely minced and washed, but not further dissociated) using [3H]-R-1881 as ligand. In RVP from castrate animals (where AR is unoccupied and cytosolic), the mean AR/DNA ratio in large epithelial clumps was 17% of the control value. However, on a protein basis, AR per milligram cytosolic protein in epithelial clumps was 80% of the unfractioned control. After disaggregation of large epithelial clumps at 20°C, the recovered cells no longer contained detectable levels of AR. The mean AR/DNA ratio in stromal cell fractions from castrate RVP was about half that found in epithelial clump fractions. In RVP from normal intact animals (where AR is occupied with endogenous DHT and predominantly localized in nuclei), AR was measured by a [3H]-R-1881 exchange assay. The mean AR/DNA ratio in epithelial clumps from normal RVP was about 45% of the value found in control tissue; in stromal fractions the mean AR/DNA ratio was about 60% of the found in epithelial clumps. Estradiol receptor (ER) in normal intact rats, measured using [3H]-R-2858 as ligand was found to be unoccupied, cytosolic, and present in low concentration relative to unoccupied, cytosolic AR in castrate RVP. Highest ER/DNA ratios were found in the stromal cellular fraction with successively lower values in unfractionated RVP and epithelial clumps. Arginase activity per unit DNA in epithelial clumps was about 28% of that found in control tissue. The mean arginase/DNA ratio in stromal fractions was about 80% of the value found in the control and consistently higher than in epithelial clumps. Thus in RVP, arginase appears to be a marker for “viability” of stromal as well as epithelial cells, rather than a specific marker for epithelial cells. The present results demonstrate that AR and ER are both present in epithelial and stromal subfractions of RVP. Since AR/DNA ratios were higher in epighelial clumps than in stromal fractions in both normal and castrate RVP, (despite the greater degree of cell damage in epithelial elements relative to stroma, as suggested by arginase content) this finding indicates that AR concentration is much higher in epithelial than in stromal cells. IN contrast, Er appears to be predominantly localized in stromal cells.

Characteristics of separated epithelial and stromal subfractions of prostate: I. Rat ventral prostate.

These studies were initiated with the objective of isolating epithelial and stromal cells of human prostatic tissue in undamaged state, in order to study the cellular distribution of steroid receptors in benign prostatic hyperplasia (BPH) relative to normal prostate. Initial experiments showed that when BPH tissue immersed in tissue culture media was progressively fragmented by various cutting procedures, epithelial elements were selectively released as clumps of variable size and individual cells, but that a large percentage of these cells were damaged, as evidenced by their failure to exclude trypan blue (TB). These observations suggested that if tissue fragmentation were carried out under defined conditions that minimize cell damage, BPH subfractions might be obtained containing a large percentage of undamaged cells. To determine conditions of tissue fragmentation which result in maximal recovery of epithelial cells which exclude TB, rat ventral prostate (RVP) was chosen as a model system. Experiments with RVP revealed that maximal yields of such cells were obtained in "large" epithelial clumps (greater than 30 cells per clump) released under the following conditions: (1) chopping the tissue with razor blades in a large volume (2 ml/100 mg RVP) of a Ca2+-free tissue culture medium ( Joklik 's-MEM) containing 1% casein, (2) carrying out the entire fractionation procedure in the cold, and (3) maintaining a 1% casein concentration in the medium during chopping, as well as in subsequent washing procedures, to protect cells from proteolytic activity. In large epithelial clumps, cells in the interior of the clump were not stained by TB but the cells at the periphery of the clump were freely permeable to TB. Single epithelial cells and small epithelial clumps (3-10 cells) released by razor blade fragmentation were also permeable to TB. When large epithelial clumps were incubated at 20 degrees C for 90 min, the clumps disaggregated into smaller clumps and morphologically intact single cells, which did not exclude TB. The residual tissue fragments remaining after chopping contained the bulk of stromal cells plus some epithelial elements. The latter could be removed by gentle rubbing of the fragments on a sieve in the presence of medium. The stromal fraction thus obtained consisted of stromal cells, embedded in mesenchymal matrix, which were not stained by TB and appeared normal when examined histologically by light microscopy.(ABSTRACT TRUNCATED AT 400 WORDS)

The effects of castration and androgen replacement on the nucleic acid composition, metabolism, and enzymatic capacities of the rat ventral prostate.

The pentose nucleic acid/desoxyribose nucleic acid ratio for normal rat ventral prostate tissue of approximately 2.4 is lowered to 0.9 or less following-castration or stilbestrol administration, while testosterone replacement returns the ratio to the “normal” value. Qo2 of prostates from 6–15 weeks castrates is about 1/5 that of the “normal” value and the RQ falls from 0.9 to 0.4. Testosterone treatment re-establishes (the “normal” Qo2 and RQ values. Zymohexase concentration of castrate tissue is lowered to 5–10% that of “normal,” while the α-glycerophosphate dehydrogenase concentration doubles. The concentrations of both enzymes in prostrates of 20-day-old immature rats are similar to those of normal adults rather than of castrates. Hy injecting increasing amounts of testosterone in 4-week castrate mature rats and measuring the zymohexase activity of the prostate tissue after 72 hours treatment, a definite threshold is demonstrated below which the activity is at the castrate level and above which there is a 20-fold increase in zymohexase activity. The acid phosphatase activity of the prostate tissue per gram wet weight falls in the range of 8–10 King- Armstrong units and is not affected by age of rat, castration or by testosterone or stilbestrol administration.