Development Of Seminal Vesicles Research Articles

Steroidogenic enzyme gene expression and testosterone production are developmentally modulated by bone morphogenetic protein receptor-1B in mouse testis.

Bone morphogenetic proteins (BMPs) and receptors (BMPR-1A, BMPR-1B, BMPR-2) have been shown to be vital for female reproduction, while their roles in males are poorly described. Our study was undertaken to specify the function of BMPR-1B in steroidogenic enzyme gene expression, testosterone production and reproductive development in male mice, given that Bmpr1b mRNA is expressed in mouse testis and Bmpr1b knockout results in compromised fertility. Male mice were passively immunized for 6 days with anti-BMPR-1B in the presence or absence of exogenous gonadotrophins. We then measured the effects of anti-BMPR-1B on testicular hydroxysteroid dehydrogenase isoforms (Hsd3b1, Hsd3b6, and Hsd17b3) and aromatase (Cyp19) mRNA expression, testicular and serum testosterone levels, and testis and seminal vesicle weight. In vitro testosterone production in response to anti-BMPR-1B was determined using testicular culture, and Leydig cell culture in the presence or absence of gonadotrophins. In Leydig cell culture the contribution of seminiferous tubules and Leydig cells were examined by preconditioning the media with these testicular constituents. In adult mice, anti-BMPR-1B increased testosterone and Hsd3b1 but decreased Hsd3b6 and Cyp19 mRNA. In adult testicular culture and seminiferous tubule conditioned Leydig cell culture, anti-BMPR-1B reduced testosterone, while in normal and Leydig cell conditioned Leydig cell culture it increased testosterone levels. In pubertal mice, anti-BMPR-1B reduced gonadotrophin stimulated seminal vesicle growth. In conclusion, BMPR-1B has specific developmental functions in the autocrine and paracrine regulation of testicular steroidogenic enzyme gene expression and testosterone production in adults and in the development of seminal vesicles during puberty.

Juvenile Parasagitta setosa (J. Müller, 1847) (Chaetognatha) from Shallow Waters of the Southern Black Sea: Temporal Size Structure, Gonad Maturity, and Gut Content

The present study aimed to assess the abundance, body length, maturity stage, and gut content of Parasagitta setosa in the southern Black Sea, Turkey. The study was conducted twice a month from January 2008 to December 2008. Vertical hauls with a 112 μm mesh size plankton net were used from a depth of 50 m to the surface of the Sinop coast. During the study period, the abundance of this species was generally low, varying between 10 and 980 ind.m-2. In particular, the abundance of P. setosa was low from December to July but increased from August. Small size individuals were predominated, with both 1 – 1.99 mm and 2 – 2.99 mm size classes accounting for 62% of the total P. setosa sample. Four developmental stages were determined based on ovary and seminal vesicle development. Stage I (immature) was the predominant developmental stage in the P. setosa population. A total of 1580 individuals were dissected; however, only 53 individuals had food items in their gut (3.4%), with copepods (54.73%) accounting for the predominant group the food content. It was determined that the abundance values and feeding ratios of P. setosa were low in the coastal area of Sinop and new individuals join in the population during the summer-autumn period.

Molecular Mechanism and Anti-Fertility Effect of Plant Complex Sterility Agent on Targeted Gene DPY19L2 in Rats.

Damage caused by rats is a serious hazard to the environment and crop irrigation. It not only results in great damage to the ecological environment, but also seriously affects the growth and yield of crops and forests. Controlling damage caused by rats is the primary task for improving the environment and maintaining ecological balance. Basing on the related gene DPY19L2 in the maturation and development of seminal vesicles in rats, our study explored the effect of non-toxic and pollution-free plant complex sterility agent on rat fertility. The results showed that the plant complex sterility agent could effectively reduce the genital organ index of male rats, change the sperm morphology, reduce the testosterone content and sperm motility, inhibit the expression of spermatogenesis genes DPY19L2, SPATA16, SUN5, and ZPBP, and achieve the effective sterility control of rat pests. Plant complex sterility agent with high concentration can effectively target rat sperm gene DPY19L2 and realize effective sterility control of rat pests.

Impact of titanium dioxide on androgen receptors, seminal vesicles and thyroid hormones of male rats: possible protective trial with aged garlic extract.

The aim of this study was to evaluate the effect of titanium dioxide (TiO2 ), a widely produced and consumed pigment in various food products, on the post-natal development of male albino rat seminal vesicle and thyroid hormones, as well as to evaluate the ameliorative effect of aged garlic extract (AGE) on TiO2 -induced alterations. Forty male rat pups (3weeks old) were divided into four equal groups. The 1st group received distilled water orally (control group), 2nd group was given 2mlkg-1 AGE, 3rd group was administered TiO2 (5gkg-1 BW) day after day for 65days, and the 4th group administered AGE 6hr prior to TiO2 gavage. TiO2 -exposed rats showed nonsignificant changes in the serum testosterone, TSH, T3 and T4 , while serum glucose showed a significant decrease. Androgen receptor (AR) mRNA expression was significantly down-regulated and weak signal of AR immune labelling. Histopathologically, the epithelium cell lining of seminal vesicles showed focal areas of necrosis and fibrous tissue with the prominent fibrous stroma of the atrophied glands. Meanwhile, AGE supplementation ameliorated the deleterious effects of TiO2 intoxication through protecting the tissues from oxidative stress caused by TiO2 . In summary, oral administration of TiO2 resulted in abnormal developmental events in male rat seminal vesicle and AGE able to reduce TiO2 toxicity.

AZD3514: A Small Molecule That Modulates Androgen Receptor Signaling and Function In Vitro and In Vivo

Continued androgen receptor (AR) expression and signaling is a key driver in castration-resistant prostate cancer (CRPC) after classical androgen ablation therapies have failed, and therefore remains a target for the treatment of progressive disease. Here, we describe the biological characterization of AZD3514, an orally bioavailable drug that inhibits androgen-dependent and -independent AR signaling. AZD3514 modulates AR signaling through two distinct mechanisms, an inhibition of ligand-driven nuclear translocation of AR and a downregulation of receptor levels, both of which were observed in vitro and in vivo. AZD3514 inhibited testosterone-driven seminal vesicle development in juvenile male rats and the growth of androgen-dependent Dunning R3327H prostate tumors in adult rats. Furthermore, this class of compound showed antitumor activity in the HID28 mouse model of CRPC in vivo. AZD3514 is currently in phase I clinical evaluation.

Temperature-Dependent Reproductive Development ofLygus hesperus(Hemiptera: Miridae)

Recent studies to elucidate relationships between the western tarnished plant bug, Lygus hesperus Knight, and injury to cotton (Gossypium spp.) have identified important differences in feeding behaviors among adults of different gender and reproductive states. These findings suggest a need for improved knowledge of L. hesperus temperature-dependent reproductive development. We used nonlinear biophysical development rate models to describe the reproductive development of adult L. hesperus held under constant temperatures from 12.8 to 35.0°C. In addition, abdominal coloration was measured as a nondestructive indicator of reproductive maturity. The nonlinear models indicated most stages of ovary, seminal vesicle, and medial accessory gland development were subject to mild high-temperature inhibition, except for the stage of filled seminal vesicles. Development of filled seminal vesicles was subject to minor low-temperature inhibition and severe high-temperature inhibition. Estimated development times reflected extensive interindividual variation, especially at low temperatures. This variation suggests the opportunity to select for more rapid or more consistent reproductive development under the conditions of laboratory culture. Although presence of a dark aqua coloration of the ventral abdominal cuticle was statistically associated with reproductive maturity, especially in female L. hesperus, color-based predictions of reproductive maturity were often inaccurate for bugs reared at temperatures above or below 26.7°C. Therefore, use of abdominal coloration as an indicator of reproductive development in ecological studies seems inappropriate. The results provide mathematical descriptions of L. hesperus temperature-dependent reproductive development which should facilitate improved planning and interpretation of studies involving manipulation of adult reproductive status.

Group IVA phospholipase A2 regulates testosterone biosynthesis by murine Leydig cells and is required for timely sexual maturation

In the present paper, we report that PLA2G4A (Group IVA phospholipase A2) is important in the development and function of rodent testes. Interstitial cells of rat testes had high PLA2 (phospholipase A2) activity that was very sensitive to the PLA2G4A-preferential inhibitor AACOCF3 (arachidonyl trifluoromethyl ketone). PLA2G4A protein was expressed primarily in the interstitial cells of wild-type mouse testes throughout maturation. Although Pla2g4a knockout (Pla2g4a-/-) male mice are fertile, their sexual maturation was delayed, as indicated by cauda epididymal sperm count and seminal vesicle development. Delayed function of Pla2g4a-/- mice testes was associated with histological abnormalities including disorganized architecture, swollen appearance and fewer interstitial cells. Basal secretion of testosterone was attenuated significantly and steroidogenic response to hCG (human chorionic gonadotropin) treatment was reduced in Pla2g4a-/- mice compared with their Pla2g4a+/+ littermates during the sexual maturation period. Chemical inhibition of PLA2G4A activity by AACOCF3 or pyrrophenone significantly reduced hCG-stimulated testosterone production in cultured rat interstitial cells. AACOCF3 inhibited forskolin- and cAMP analogue-stimulated testosterone production. These results provide the first evidence that PLA2G4A plays a role in male testes physiology and development. These results may have implications for the potential clinical use of PLA2G4A inhibitors.

A high‐resolution molecular atlas of the fetal mouse lower urogenital tract

Epithelial-stromal interactions in the lower urogenital tract (LUT) are integral to prostatic and seminal vesicle development in males, vaginal and uterine development in females, and urethral development in both sexes. Gene expression profiling of isolated LUT stroma and epithelium has unraveled mechanisms of LUT development, but such studies are confounded by heterogeneous and ill-defined cell sub-populations contained within each tissue compartment. We used in situ hybridization to synthesize a high-resolution molecular atlas of 17-day post-coitus fetal mouse LUT. We identified mRNAs that mark selective cell populations of the seminal vesicle, ejaculatory duct, prostate, urethra, and vagina, subdividing these tissues into 16 stromal and 8 epithelial sub-compartments. These results provide a powerful tool for mapping LUT gene expression patterns and also reveal previously uncharacterized sub-compartments that may play mechanistic roles in LUT development of which we were previously unaware.

Identification of a Transcription Factor, BHLHB8, Involved in Mouse Seminal Vesicle Epithelium Differentiation and Function1

The seminal vesicle is a male accessory sex organ that develops from segments of the Wolffian duct adjacent to the urogenital sinus. It produces most of the seminal plasma in both humans and rodents. To date, very few transcription factors have been linked to the development and differentiation of seminal vesicles. In this study, we have examined the role of basic helix-loop-helix (BHLH) B8 transcription factor expressed at high levels in the adult seminal vesicle and during seminal gland differentiation. Immunofluorescent studies indicate that BHLHB8 is expressed within the epithelial layer of the seminal layer of the seminal vesicle following branching morphogenesis but prior to full maturation of cell morphology and function. Analysis of mice that do not express BHLHB8 (Bhlhb8(-/-)) indicates no deficiency in the initial development of the seminal vesicle. However, morphological and ultrastructural analysis indicates disruption of the epithelial cellular architecture. The seminal vesicle epithelial layer of 2-mo-old Bhlhb8(-/-) mice shows extensive cellular degeneration based on the appearance of reduced microvilli, altered granule size, and dilated endoplasmic reticulum and Golgi apparatus. The seminal vesicle epithelial cells also degenerate prematurely, as evidenced by disruption of nuclear architecture and significant accumulations of autophagic bodies. These results identify BHLHB8 as a regulator in establishing and stabilizing the secreting epithelial cells of the seminal vesicle.

Branching morphogenesis in the prostate gland and seminal vesicles

The prostate gland and seminal vesicles are the major exocrine glands in the male reproductive tracts of mammals. Although the morphology of these organs varies widely among species, epithelial branching morphogenesis is a key feature of organ development in most mammals including rodents and humans. Insight into the mechanisms that control prostatic and seminal vesicle branching morphogenesis has come from experimental embryological work as well as from the study of mice and humans harboring mutations that alter branching morphogenesis. These studies have demonstrated a requirement for androgens to initiate branching morphogenesis as well as a role for androgens in sustaining the normal rate and extent of branching. In addition, these studies have revealed a series of reciprocal paracrine signals between the developing prostatic epithelium and prostatic mesenchyme that are essential for regulating branching morphogenesis. Key growth factors that participate in these signaling events include members of the fibroblast growth factor, Hedgehog, and transforming growth factor-β families. Additional genes including several homeobox-containing transcription factors have also been implicated as key regulators of prostatic and seminal vesicle branching morphogenesis. While research in recent years has greatly enhanced our understanding of the molecular control of prostatic and seminal vesicle development, known genes cannot yet explain in molecular terms the complex biological interactions that descriptive and experimental embryological studies have elucidated in the control of branching morphogenesis in these organs.

Spontaneous mutation in mice provides new insight into the genetic mechanisms that pattern the seminal vesicles and prostate gland.

The seminal vesicles and prostate gland are anatomically adjacent male sex-accessory glands. Although they arise from different embryonic precursor structures and express distinct sets of secretory proteins, these organs share common features in their developmental biology. A key shared developmental feature is the elaboration of complex secretory epithelia with tremendous surface area from simple precursor structures with juxtaposed epithelial and mesenchymal cells. In this study, new insight into the nature of the biological processes that underlie glandular morphogenesis is achieved by analyzing the phenotypes present in mice that harbor a spontaneous mutation, seminal vesicle shape (svs), previously identified for causing altered seminal vesicle morphology in adults. An examination of seminal vesicle development in svs mice provides the first evidence that the concurrent processes of epithelial branching and epithelial infolding are distinct processes under separate genetic control. It also provides the first direct evidence that the thickness and topology of the smooth muscle layer in the seminal vesicles are determined by interaction with the glandular epithelium during the branching process. In addition, the seminal vesicle phenotype in svs mice is shown to phenocopy the morphologic form present in certain other mammals such as the guinea pig, raising the possibility that the svs mutation is the sort of variant that arises during evolution. By also including an investigation of the prostate gland, this study also identifies previously unrecognized phenotypes in svs prostates, including increased gland size and dramatically reduced levels of branching morphogenesis. Finally, this study advances the goal of identifying the svs gene by mapping the svs mutation relative to known molecular markers and testing Fgfr2 as a candidate gene. The finding that the svs mutation maps to a genomic region syntenic to a region frequently deleted in human prostate tumors, together with the prostatic phenotype present in svs mice, further raises the interesting possibility that the svs mutation will identify a candidate prostate tumor suppressor gene.

Effects of oxytocin on semen release response in African catfish ( Clarias gariepinus)

In silurid fishes, semen collection is practically impossible, even after hormonal stimulation. Instead, males are killed and testes macerated to obtain sperm. To understand the endocrine control of semen release in catfishes, we investigated the role of smooth muscle contractors in semen release and semen quality of African catfish ( Clarias gariepinus). In in vitro experiments, testis slices were incubated with oxytocin (1 and 10 IU), isotocin (2 and 20 ug), vasopressin (0.2 and 2 ug), epinephrine (1 and 10 ug), PGF2α (1 and 10 ug), purified Clarias LH (300 ng) and partly purified Clarias pituitary extract (containing 300 ng LH). Only oxytocin increased sperm concentration of the medium (assessed by optical density measurements) compared to control incubations. Oxytocin was then tested in vivo in two groups of fish: normal males, and males that had been treated with 17α-methyltestosterone during larval stages to inhibit seminal vesicle development (MT males). Both groups of fish received two doses of carp pituitary suspension (8 and 10 mg/kg, respectively i.m.) with or without subsequent oxytocin treatment (5 IU/kg i.v.; cPS-OT treatment and cPS treatment, respectively). There was no effect of oxytocin on the number of strippable males. Of cPS and cPS-OT treated fish, 87% MT males and 60% normal males were strippable. The stripped semen volume was low in both groups but MT males produced higher ( P<0.001) hatching rates (63.1%) than did normal males (2.1%).

Critical windows of vulnerability for effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on prostate and seminal vesicle development in C57BL/6 mice.

A single maternal dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on gestation day (GD) 13 can greatly impair ventral prostate, dorsolateral prostate, anterior prostate, and seminal vesicle development in wild-type C57BL/6 mice. The developmental stages at which these organs are most sensitive to TCDD exposure have now been investigated. Pregnant mice were dosed orally with 5 micro g TCDD/kg or vehicle on GD 13, and their pups were fostered at birth to dams of the same treatment or cross-fostered to dams of the opposite treatment. Additional males had in utero and lactational TCDD exposure following maternal dosing on GD 16. Organ weights and secretory protein, cytokeratin 8, and cyclophilin mRNA expression were determined at 35 days of age. Effects of TCDD on ventral prostate development were due primarily to in utero exposure; the critical window was between GD 13 and birth. Dorsolateral prostate development was inhibited about equally by in utero or lactational exposure, and vulnerability did not begin until GD 16. Anterior prostate development was also affected by both in utero and lactational TCDD exposure, particularly the former. Vulnerability began before GD 16 and continued into postnatal life. Seminal vesicle development was essentially unaffected by in utero or lactational exposure alone but was significantly inhibited by combined exposure, regardless of whether dams were dosed on GD 13 or 16. In summary, the time during which each organ was most vulnerable to TCDD exposure varied from one organ to another. These findings provide insights into the developmental processes that TCDD inhibits in each organ, and demonstrate that TCDD inhibits ventral prostate development before this organ first appears, presumably via effects on the urogenital sinus. The observation that in utero TCDD exposure (alone) inhibited development of each prostate lobe is significant because previous studies have shown that little TCDD is transmitted to mice before birth.

Effects of aryl hydrocarbon receptor null mutation and in utero and lactational 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure on prostate and seminal vesicle development in C57BL/6 mice.

Experiments were conducted to determine the effects of aryl hydrocarbon receptor (AhR) null mutation and in utero and lactational 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure, alone and in combination, on prostate and seminal vesicle development in C57BL/6 mice. AhR heterozygous (Ahr+/-) mice were mated, and pregnant females were dosed orally on gestation day 13 with TCDD (5 microg/kg) or vehicle. Pups underwent necropsy on postnatal days (PNDs) 35 and 90. Comparison of vehicle-exposed AhR knockout (AhRKO;Ahr-/-) with wild-type (Ahr+/+) pups revealed that the AhR is necessary for normal dorsolateral prostate, anterior prostate, and seminal vesicle development but apparently not for ventral prostate development. In wild-type mice,in utero and lactational TCDD exposure reduced ventral prostate weight by 79-87% and mRNA expression for its major androgen-dependent secretory protein (MP25) by 99%. Yet high levels of mRNA for a secretory protein normally produced primarily by the lateral prostate (PSP94) were expressed. These effects were predominantly AhR dependent because TCDD had little if any effect in AhRKO mice. TCDD reduced dorsolateral prostate weight in wild-type but not AhRKO mice and had no significant effect on expression of mRNA for PSP94 or for probasin, a major androgen-dependent secretory protein. The PSP94 results suggest that TCDD may have caused a respecification of prostatic gene expression. TCDD reduced anterior prostate weight by more than half, and expression of mRNA for its major androgen-dependent secretory protein (renin-1) was greatly reduced. These effects were AhR dependent. Seminal vesicle weight was reduced by TCDD in wild-type mice but was increased in AhRKO mice on PND 35 and decreased on PND 90 (relative weight only). Androgen receptor mRNA levels were not significantly altered in any prostate lobe, and all organs appeared histologically normal in all groups. Serum testosterone concentrations were unchanged, and modest reductions in serum 5alpha-androstane-3alpha,17beta-diol concentrations could not account for the effects on sex organs. Collectively, these results indicate that the AhR signaling pathway plays a role in normal accessory sex organ development and thatin utero and lactational TCDD exposure disrupts development of these organs via spatially and perhaps temporally specific mechanisms.

Effects of 17alpha-methyltestosterone on seminal vesicle development and semen release response in the African catfish, Clarias gariepinus

The effects of 17alpha-methyltestosterone on seminal vesicle development in the African catfish, Clarias gariepinus, were investigated in an attempt to improve semen collection from this species. Treatment of larvae with dietary 17alpha-methyltestosterone at 50 mg kg(-1) for days 12-33 or days 12-40 after hatching, or at 20 mg kg(-1) for days 12-26, 12-33, 12-40 or 12-47 after hatching inhibited the development of the seminal vesicle finger-like extensions in male catfish, but did not affect the sex ratio. The minimum effective dose and period of treatment to inhibit seminal vesicle development in all male catfish treated with 17alpha-methyltestosterone was 20 mg kg(-1) for days 12-40 after hatching. Male catfish from this treatment group developed normal testes that, in some cases, contained a few oocytes, which tended to disappear before sexual maturation. After sexual maturation, the semen release response was evaluated in males with incomplete seminal vesicles. Fluid with viable spermatozoa was obtained after two consecutive injections of carp pituitary suspension, from 10 of 19 males that had been fed 20 mg 17alpha-methyltestosterone kg(-1) for days 12-40 or days 12-47 after hatching, but from only 4 of 15 males that did not receive any dietary steroid. Intratesticular semen quality was not affected by 17alpha-methyltestosterone treatment. The results of this study demonstrate that the absence of seminal vesicle extensions induced by treatment with 17alpha-methyltestosterone facilitated the collection of semen by stripping from this species of fish.

Effects of 17alpha-methyltestosterone on seminal vesicle development and semen release response in the African catfish, Clarias gariepinus.

The effects of 17alpha-methyltestosterone on seminal vesicle development in the African catfish, Clarias gariepinus, were investigated in an attempt to improve semen collection from this species. Treatment of larvae with dietary 17alpha-methyltestosterone at 50 mg kg(-1) for days 12-33 or days 12-40 after hatching, or at 20 mg kg(-1) for days 12-26, 12-33, 12-40 or 12-47 after hatching inhibited the development of the seminal vesicle finger-like extensions in male catfish, but did not affect the sex ratio. The minimum effective dose and period of treatment to inhibit seminal vesicle development in all male catfish treated with 17alpha-methyltestosterone was 20 mg kg(-1) for days 12-40 after hatching. Male catfish from this treatment group developed normal testes that, in some cases, contained a few oocytes, which tended to disappear before sexual maturation. After sexual maturation, the semen release response was evaluated in males with incomplete seminal vesicles. Fluid with viable spermatozoa was obtained after two consecutive injections of carp pituitary suspension, from 10 of 19 males that had been fed 20 mg 17alpha-methyltestosterone kg(-1) for days 12-40 or days 12-47 after hatching, but from only 4 of 15 males that did not receive any dietary steroid. Intratesticular semen quality was not affected by 17alpha-methyltestosterone treatment. The results of this study demonstrate that the absence of seminal vesicle extensions induced by treatment with 17alpha-methyltestosterone facilitated the collection of semen by stripping from this species of fish.

The BMP Family Member Gdf7 Is Required for Seminal Vesicle Growth, Branching Morphogenesis, and Cytodifferentiation

Epithelial–mesenchymal interactions play an important role in the development of many different organs and tissues. The secretory glands of the male reproductive system, including the prostate and seminal vesicles, are derived from epithelial precursors. Signals from the underlying mesenchyme are required for normal growth, branching, and differentiation of the seminal vesicle epithelium. Here, we show that a member of the BMP family, Gdf7, is required for normal seminal vesicle development. Expression and tissue recombination experiments suggest that Gdf7 is a mesenchymal signal that acts in a paracrine fashion to control the differentiation of the seminal vesicle epithelium.

The effects of oral administration of methyltestosterone on seminal vesicle development, in African catfish

The effects of oral administration of methyltestosterone on seminal vesicle development, in African catfish

Effects of Steroid Hormones and Growth Factors on the Development of the Male Mouse Reproductive TractIn Vitro

In order to determine what growth-promoting factors may be involved in androgen-induced male reproductive tract development, the newborn mouse urogenital sinus region with seminal vesicles attached was cultured for 5 days on collagen gel matrix in a serum-free medium composed of DMEM and Ham's F-12 (1:1) supplemented with BSA, insulin, cholera toxin and transferrin. Testosterone and 5 α-dihydrotestosterone (DHT) stimulated development of seminal vesicle (SV), coagulating gland (CG), prostate (P) and bulbourethral gland (BG). Epidermal growth factor (EGF) stimulated development of CG, P and BG, but inhibited that of SV. Transforming growth factor-α (TGF-α) inhibited SV development, but had stimulatory effects on both CG and P. Addition of anti-EGF antibody significantly inhibited the DHT-induced development of CG and BG, but not of SV and P. These findings suggest that both EGF and TGF-α have organspecific regulatory actions on male reproductive tract development and that EGF may mediate the action of DHT in the development of CG and BG.

Inhibitory effects of retinoic acids on androgen-dependent development of neonatal mouse seminal vesicles in vitro.

The effects of retinoic acids (RAs) on development of seminal vesicles (SVs) of neonatal mice were investigated in vitro. SVs from 0-day-old male mice were cultured for 2-6 days in serum-free, chemically defined medium containing transferrin and BSA supplemented with 5alpha-dihydrotestosterone (DHT; 10(-8) M) and insulin (10 microg/ml), alone and in combination. Before culture, SVs from 0-day-old mice consisted of an unbranched epithelium surrounded by mesenchyme. SVs cultured in medium with DHT plus insulin or DHT alone formed numerous epithelial branches after day 2 of culture, whereas epithelial branching did not occur in SVs cultured with insulin alone. All-trans-RA or 13-cis-RA (10(-9)-10(-6) M) added to medium containing DHT plus insulin or DHT alone inhibited epithelial branching in a dose-dependent manner. This inhibitory effect was reversible after removal of the retinoids from the medium on day 4 of culture. These RAs also decreased [3H]thymidine labeling indexes of both epithelium and mesenchyme of SVs cultured in medium with DHT plus insulin or DHT alone and inhibited the increase in their protein contents. 9-Cis-RA was less inhibitory than all-trans-RA or 13-cis-RA on epithelial branching, [3H]thymidine labeling indexes of epithelium and mesenchyme, and protein content of SVs cultured in medium with DHT and insulin. In the absence of DHT (insulin alone), all-trans-RA did not affect either the [3H]thymidine labeling indexes of epithelium and mesenchyme or the protein content of cultured SVs. Reverse transcriptase-PCR demonstrated strong expression of transcripts for mouse RA receptors (RARalpha, RARgamma, and RXRalpha), with lower levels of expression of RARbeta, RXRbeta, and RXRgamma in neonatal SVs. The present results indicate that RAs reversibly inhibit androgen-dependent development of neonatal mouse SVs, most likely through RARs.