Congenital absence of the vas deferens: Cystic fibrosis transmembrane regulatory gene mutations

Congenital absence of the vas deferens (CAVD) is a rare genetic condition first discovered in the mid-18th century related to mutations in the cystic fibrosis transmembrane regulatory genes. The condition is typically found during work-up of male infertility, and the majority of cases can be diagnosed with complete history and physical examination and pertinent investigations. The condition can be separated into three subcategories, and genetic advances have led to a much better understanding behind the disease, its pathogenesis, and options for treatment. In this review, we discuss the genetics, pathogenesis, embryology, and diagnosis of treatment of CAVD. Future work in this area likely will aim to better understand the epigenetic factors that influence the development of the condition in order to identify potential upstream therapeutic targets.

Complete urogenital nonunion

A 7.5-year-old boy was admitted to our department with left undescended testis. On surgical exploration, the vas deferens and epididymis were normal in appearance in its route to the scrotum, but no obvious testis or testis-like structure was identified. Exploration was extended to the abdominal cavity via the processus vaginalis, and the testis was found near the sigmoid colon without any connection to the vas deferens and epididymis. The testis was freed from surrounding structures preserving the testicular vasculature, and an orchidopexy was performed. In cases of nonpalpable testis with the vas deferens and epididymis reaching to the scrotum, an intra-abdominal testis owing to a nonunion phenomenon must be considered, and extended exploration should be performed.

Region-specific inhibition of prostatic epithelial bud formation in the urogenital sinus of C57BL/6 mice exposed in utero to 2,3,7,8-tetrachlorodibenzo-p-dioxin

In utero 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure causes abnormal ventral, dorsolateral, and anterior prostate development in wild-type but not aryl hydrocarbon receptor (AhR) null mutant C57BL/6 mice. Experiments have now been conducted to test the hypothesis that TCDD causes an AhR-dependent inhibition of the earliest visible stage of prostate development, the formation of prostatic buds by urogenital sinus (UGS) epithelium. A novel method for viewing budding was developed that uses scanning electron microscopy of isolated UGS epithelium instead of three-dimensional reconstruction of serial histological sections of intact UGS. In the initial experiment, the time course for prostatic epithelial bud formation in vehicle- and TCDD-exposed wild-type C57BL/6J mice was determined. A single maternal dose of TCDD (5 mug/kg) on gestation day 13 delayed the appearance of dorsal, lateral, and anterior buds by about one day, reduced dorsolateral bud number, and prevented ventral buds from forming. No such effects were seen in TCDD-exposed AhR null mutant fetuses, while AhR null mutation, alone, had no detectable effect on budding. Treatment of wild-type dams with sufficient 5alpha-dihydrotestosterone (DHT) to masculinize female fetuses failed to protect against the inhibition of budding caused by TCDD. These results demonstrate that in utero TCDD exposure causes an AhR-dependent inhibition of prostatic epithelial bud formation commensurate with its inhibitory effects on ventral and dorsolateral prostate development, and that the inhibition of budding is not due to insufficient DHT. Inhibited bud formation appears to be the primary cause of abnormal prostate development in TCDD-exposed mice.

Proteomic profiling of epididymis and vas deferens: identification of proteins regulated during rat genital tract development

Epididymis and vas deferens form part of the male internal genital tract and are dependent on androgens for their growth and development. To better understand the molecular action of androgens during male genital tract development, protein expression profiles were generated using two-dimensional gels, for rat epididymides and vasa deferentia isolated on embryonic days (E) 17-21. Proteins that were differentially expressed between E17 and E21 were cut from the gels, digested into tryptic peptides and analyzed on a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer. Using this approach, 20 proteins could be identified that were regulated in time and were categorized into cytoskeletal proteins, nuclear proteins, transport proteins, chaperones, and enzymes (mainly glycolytic). Furthermore, epididymides and vasa deferentia isolated on E19 were cultured in vitro in the absence or presence of 10 nm of the synthetic androgen R1881, for 9, 24, and 48 h. Under these conditions, regulation and posttranslational modification were observed for glyceraldehyde 3-phosphate dehydrogenase, triosephosphate isomerase, heterogeneous nuclear ribonucleoprotein A2/B1 and heterogeneous nuclear ribonucleoprotein A3, similar to the observed changes in vivo. In addition, posttranslational modification of RhoGDI1 (also named RhoGDIalpha) was found in response to androgen. Androgen-induced posttranslational modification of RhoGDI1 and glycolytic enzymes may be an important functional link between signaling pathways and cytoskeletal rearrangements in control of growth and development of the male internal genital tract.

Proteomic analysis of androgen-regulated protein expression in a mouse fetal vas deferens cell line

During sex differentiation, androgens are essential for development of the male genital tract. The Wolffian duct is an androgen-sensitive target tissue that develops into the epididymis, vas deferens, and seminal vesicle. The present study aimed to identify androgen-regulated proteins that are involved in development of Wolffian duct-derived structures. We have used male mouse embryos transgenic for temperature-sensitive simian virus 40 large tumor antigen at 18 d of gestation, to generate immortalized mouse fetal vas deferens (MFVD) parental and clonal cell lines. The MFVD parental and clonal cell lines express androgen receptor protein and show features of Wolffian duct mesenchymal cells. Clonal cell line MFVD A6 was selected for proteomic analysis and cultured in the absence or presence of androgens. Subsequently, two-dimensional gel electrophoresis was performed on total cell lysates. Differentially expressed proteins were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and two androgen-regulated proteins were identified as mElfin and CArG-binding factor-A (CBF-A). CBF-A and mElfin are known to bind to cytoskeletal F-actin. Both proteins appeared to be regulated by androgens at the posttranslational level, possibly involving phosphorylation. Posttranslational modification of mElfin and CBF-A by androgens may be associated with a cytoskeletal change that is involved in androgen-regulated gene expression.

[Unilateral agenesis of structures dependent on the mesonephric duct. Presentation of a case]

The mesonefric duct plays an essential role in the development of the genitourinary tract. From that duct derive structures as the ureter, the vas deferens and the seminal vesicles. Also, the ureteral bud interact with the mesonefric blastema and induce its conversion to renal tissue. The origin of these anomalies of the embrionary development is unknown. In some cases, mutations on the gene of the cystic fibrosis (CFRT) could play a role, assuming that there is a relationship between the congenital absence of the vas deferens and the cystic fibrosis. Usually, the absence of these structures has a silent course. Thus, the most important diagnostic factor is the clinical suspicion. The knowledge of this association can lead to the diagnosis of other congenital abnormalities. In addition, it is important to know that these anomalies could be present isolated as expression of other non-urological diseases, specially the cystic fibrosis, the most common hereditary disease between the Caucasian race.

gon-4, a cell lineage regulator required for gonadogenesis in Caenorhabditis elegans

The gon-4 gene is required for gonadogenesis in the nematode Caenorhabditis elegans. Normally, two precursor cells, Z1 and Z4, follow a reproducible pattern of cell divisions to generate the mature somatic gonadal structures (e.g., uterus in hermaphrodites, vas deferens in males). In contrast, in gon-4 mutants, the Z1/Z4 cell lineages are variably aborted in both hermaphrodites and males: Z1 and Z4 divide much later than normal and subsequent divisions are either absent or severely delayed. In gon-4 adults, normal somatic gonadal structures are never observed, and germ-line and vulval tissues, which depend on somatic gonadal cues for their development, are also aberrant. In contrast, nongonadal tissues and the timing of other developmental events (e.g., molts) appear to be normal in gon-4 mutants. The gon-4 alleles are predicted to be strong loss-of-function or null alleles by both genetic and molecular criteria. We have cloned gon-4 in an attempt to learn how it regulates gonadogenesis. The gon-4 gene encodes a novel, acidic protein. A GON-4::GFP fusion protein, which rescues a gon-4 mutant to fertility, is expressed in somatic gonadal cells during early gonadal development. Furthermore, this fusion protein is nuclear. We conclude that gon-4 is a regulator of the early lineage of Z1 and Z4 and suggest that it is a part of a genetic program common to the regulation of both hermaphrodite and male gonadogenesis.

The paratesticular region: histoanatomic and general considerations

The paratesticular region includes the testicular collecting system, the testicular tunics, and spermatic cord. For the purpose of discussion in this issue, the rete testis is also considered part of the paratestis, although it is principally intratesticular in location. The embryologic origins of the paratesticular components and their detailed anatomic and histologic features are presented to provide a background to better understand the pathologic processes affecting the paratestis. A wide variety of cysts, hyperplasias, neoplasms, and tumor-like conditions may affect the paratesticular region, at times resulting in challenging problems in differential diagnosis. An approach to the paratesticular causes of an intrascrotal mass lesion is presented.

Structure and autonomic innervation of the human vas deferens: a review

The motor innervation of the smooth muscle coat of the human vas deferens is predominantly noradrenergic in type while a less dense and differently distributed presumptive cholinergic innervation is also in evidence, although the precise role of the latter is undetermined. Immunohistochemical studies have confirmed the presence of catecholamine-synthesizing enzymes tyrosine hydroxylase (TH) and dopamine beta hydroxylase (DbetaH) in the majority of fine, varicose intramuscular nerves, about two-thirds of which also contain neuropeptide Y (NPY). Minor populations of noradrenergic nerves contain enkephalin (ENK), galanin (GAL), somatostatin (SOM), or nitric oxide synthase (NOS). The presumptive cholinergic intramuscular nerves contain vasoactive intestinal polypeptide (VIP) and NPY. The subepithelial nerves of the vas deferens are assumed to have a secretomotor function and are rich in acetylcholinesterase and NPY, many also containing either VIP or NOS. The muscle coat of the human vas deferens is poorly differentiated until after birth, the intramuscular nerves in the fetus being relatively thick and non-varicose. Development of a subepithelial nerve plexus lags behind that in the muscle coat but its density in the neonatal vas deferens resembles that seen in the adult. Observations on specimens of human vas deferens obtained at vasovasostomy carried out 1 to 15 years after vasectomy have shown a marked reduction in the density of noradrenergic nerves in the muscle coat of the testicular portion while that in the urethral portion remains unaltered. Furthermore, the subepithelial secretomotor nerves degenerate in the testicular portion. These long-term changes in the pattern of innervation of the vas deferens consequent upon vasectomy may have profound effects upon the outcome of vasovasostomy with respect to subsequent sperm maturation, transport, and viability.

Is routine pathological evaluation of pediatric hernia sacs justified?

BACKGROUND/PURPOSE

Herniorrhaphy is the most common general surgical procedure performed on children, and hernia sac material is one of the most common tissue specimens microscopically examined in the authors' surgical pathology laboratory. The risk of accidental vas deferens ligation has prompted the recommendation that all hernia sacs be examined pathologically. The authors hypothesized that the incidence of unrecognized vas deferens or epididymis ligation is actually very low and may not warrant routine pathological examination of all pediatric hernia sacs.

METHODS

Over a 3-year period (1994 to 1996), pathology reports from all hernia repairs at the authors' institution were reviewed. A total of 1,494 inguinal hernia sacs were pathologically evaluated from 1,077 pediatric patients (417 were bilateral). Pathological diagnoses not affecting clinical management (ie, chronic inflammation, irritated hernia sacs, embryonal remnants, adrenal cortical rests) were classified as incidental findings. Identification of true vas deferens was classified as a positive finding.

RESULTS

The study population had a mean age of 3.9 +/- 0.1 years and 963 (89%) were boys. The incidence of vas deferens injury from herniorrhaphy was found to be 0.13% (2 of 1,494), and these were recognized by the pediatric surgeon in the operating room.

CONCLUSIONS

When vas deferens injury is suspected, the sample should always be sent to the pathology department for confirmation. However, no occult carcinoma or other pathology was identified, and the remainder of the histological findings did not change the clinical treatment of any child. Given a fixed cost of pathological analysis, elimination of routine hernia sac examination may result in substantial annual savings. Therefore, in the current era of cost containment, recommendations for routine pathological examination of excised pediatric hernia sacs should be reevaluated.

[Congenital bilateral agenesis of the vas deferens associated with cystic fibrosis. A molecular genetic study]

OBJECTIVE

To analyze the association of congenital bilateral agenesis of the vas deferens and cystic fibrosis.

METHODS

Three azoospermic patients with surgically confirmed congenital agenesis of the vas deferens in whom a molecular genetics study had been performed to discard the more common mutations of cystic fibrosis are described and the literature reviewed.

RESULTS

All patients showed azoospermia. The molecular genetics study showed one of the patients to be a heterozygotic carrier of G542X and no other mutations like the remaining patients.

CONCLUSIONS

15% of patients with azoospermia have chromosomal anomalies. Recently, it has been reported that 50%-65% of patients with congenital bilateral agenesis of the vas deferens have mutations for the CFTR gene, with more than 400 reported. Patients with bilateral agenesis and their partners should be screened for cystic fibrosis prior to any in vitro fertilization techniques.

Multicystic kidney joined to the homolateral testis by an ectopic vas deferens: embryological hypothesis for a new description

Ectopic location of the vas deferens is a rare congenital anomaly with multiple variations. The frequent association with ano-rectal abnormalities and hypospadias is well known. We report two cases of a newborn and a 3-year-old child with ectopic vas deferens coupled with a left multicystic kidney without any ureteral structure. Furthermore, the latter had a contralateral vesicoureteral reflux and anal agenesis with recto-bulbar fistula. Our attempt with this report is to explain the development of such anomalous deferential outlet into the multicystic kidney, according to the most qualified theory of the Wolffian duct embryology.

Morphometric and immunocytochemical study of the fetal, infant, and adult human vas deferens

The human vas deferens (VD) is often considered simply as a conduit to transfer mature sperm from the epididymis to the ejaculatory duct. The cells that make up the epithelium of the VD, however, exhibit many characteristics of cells found in more complex epithelia, which are involved in absorption and/or secretion. In the present investigation, morphometry was utilized to characterize in detail the changes incurred by the human VD during its development, growth, and aging and to determine if these changes correlate with testicular maturation. In addition, the specific types of keratins present in the epithelial cells were defined, as well as desmin distribution in the muscular layers, during the various phases of the development, growth, and involution of the human VD. Results of the morphometric study are consistent with the interpretation that the development, growth, and aging of the VD are delayed, but parallel to, the identical phases exhibited by the human testis. Further, a differential expression of distinct keratin types was observed in the VD during the various phases examined in this study. Taken together, these two correlations may suggest that the VD is unlikely to function solely as a conduit for sperm. The rationale for this interpretation is as follows: 1) the complex developmental and maturational changes measured in the present investigation in the human VD are common to other absorptive and/or secretory epithelia; and 2) these changes parallel developmental changes observed in other androgen-dependent epithelia of the male reproductive tract, which also function to contribute components to seminal fluid as well as to provide a conduit for sperm.

Normal vas deferens in fetuses with cystic fibrosis

PURPOSE

Infertility in patients with cystic fibrosis has been attributed to the congenital bilateral absence of the vas deferens. We studied the vas deferens in cystic fibrosis fetuses to determine whether this condition could be related to primary developmental abnormalities or to secondary obstructions.

MATERIALS AND METHODS

Two cystic fibrosis male fetuses, with deltaF508+/+ and deltaF508/G542X genetic mutations, were examined after abortion at 12 and 18 weeks, respectively. The lumens of the vas deferens were measured using histological serial sections in the 2 cystic fibrosis fetuses and in 6 control fetuses.

RESULTS

The vas deferens of cystic fibrosis and control fetuses showed a similar development. The diameters of the lumens were smaller at the extremities than in the medial part of the duct in cystic fibrosis and in control fetuses. No epithelial necrosis, focal dilatation or fibrous stenosis could be detected at any age. Secretions were observed in the lumen of the vas deferens of the homozygous fetus, but no obstruction was detected.

CONCLUSIONS

The normal organogenesis of the vas deferens, the presence of secretions filling the lumen of the deltaF508 +/+ fetus and the high proportion of normal ducts reported in prepubertal male cystic fibrosis patients suggest a mechanism of luminal obstruction resulting in duct atrophy and infertility in male adults with cystic fibrosis. The term "atresia" or "inspissation" should be used in cases of congenital bilateral absence of the vas deferens associated with cystic fibrosis mutations, whereas the term "agenesis" should be used for cases of congenital bilateral absence of the vas deferens associated with urogenital abnormalities in which regional defects occur during organogenesis.

[Malformations of Wolffian duct derived male genital organs (epididymis, vas deferens, seminal vesicules, ejaculatory ducts)]

OBJECTIVES

To analyse embryological phenomena, in order to define a practical approach to management.

METHODS

The authors reviewed the files of eight boys with an abnormality of Wolffian duct derived genital organs, consisting of three cases of vas deferens agenesis, two of which were accompanied by homolateral renal agenesis, one case of ectopic vas deferens with contralateral renal agenesis, three cases of duplicated vas deferens and one congenital seminal vesicle cyst with renal agenesis.

DISCUSSION

Congenital malformations of the epididymis consist of cysts and agenesis or partial atresia. Cysts essentially raise a problem of differential diagnosis. Treatment is only required in the case of severe discomfort. Vas deferens agenesis is the commonest lesion, an incidental finding in children. An experimental treatment is proposed in adults. Duplications, interdeferential communications and deferentomegaly are much rarer lesions. Seminal vesicle cysts are well visualized by transrectal ultrasonography and should be treated surgically. Lastly, ejaculatory ducts may present urethroseminal reflux or may be ectopic.

CONCLUSION

The possibility of absent or ectopic vas deferens should be considered in the case of unilateral renal agenesis. Vas deferens agenesis justifies examination of the contralateral side and investigation to exclude renal agenesis. Congenital cysts of the epididymis only require surgery when they are symptomatic. The presence of ipsilateral renal agenesis should be investigated in the case of cystic dilatation of the seminal vesicle.

Mutations in the cystic fibrosis gene in men with congenital bilateral absence of the vas deferens

This paper reviews the relationship between mutations in the cystic fibrosis (CF) gene (CFTR mutations) and congenital bilateral absence of the vas deferens (CBAVD). Two CFTR mutations were identified in 14.5% of the 449 man with CBAVD thus far reported in the literature while one CFTR mutation was found in another 48.1%. CBAVD appears to be a heterogeneous genetic condition, many cases being mild forms of cystic fibrosis, others having no relationship with CF. The 5T allele has also been found in 46% of men with CBAVD, but is not associated by the 'classical' picture of cystic fibrosis. The role of the CFTR gene presumably extends beyond a normal development of the vas deferens, possibly playing a role in spermatogenesis. The detection of CFTR mutations in CBAVD had considerable implications in genetic counselling. Couples requesting microsurgical epididymal sperm aspiration/in-vitro fertilization and those in which the man has CF should be offered CFTR mutations screening if CBAVD is the cause of the male infertility.

Morphogenesis of the axolotl pronephric duct: a model system for the study of cell migration in vivo

Pronephric duct (PND) morphogenesis is a critical early event in the development of the vertebrate excretory system. This structure is the exit channel for both pronephric and mesonephric filtrate, forms the ureteric bud of the metanephros and gives rise to the ductus deferens of the testis. In addition, the PND and ureteric bud epithelia induce terminal differentiation of the mesonephric and metanephric mesenchyme, respectively. Elongation of the PND in all vertebrates involves active cell migration of the primordium. In urodele embryos--unlike in some anuran, avian and mammalian embryos--elongation of the PND occurs solely by cell migration. In the axolotl embryo, the PND primordium segregates as an ovoid tissue mass from the anterodorsal flank mesoderm directly beneath somites 3-7. The primordium then extends caudally along the ventral border of the developing somites until it reaches the cloaca. The ease with which these embryos can be manipulated microsurgically makes the PND system ideal for the study of the mechanisms controlling cell migration in vivo. This review summarizes the progress that has been made in characterizing the environmental cues and the cell surface recognition systems that drive this tightly regulated migration event.

[Bilateral persistence of the common mesonephric duct in children. Apropos of a case. Review of the literature]

We report a case of bilateral persistence of the common mesonephric duct in a child. This anomaly is an error of implantation of the vas deferens in the distal part of the Wolffian duct. This abnormality is extremely rare (6 cases have been reported in the world literature). The diagnosis is usually incidental during laparotomy or on retrograde cystography (vesico-ureteric and vesico-deferential reflux). It is simple to treat: bilateral deferential ligation in view of the context of multiple malformations, in order to prevent ascending genital infections (prostatitis, epididymitis, testicular abscess). Only one case has been reported in adults, presenting in the form of a septic complication. This diagnosis must be considered in a context of atypical urogenital infection in a subject with other congenital abnormalities.

Volume-sensitive chloride currents in primary cultures of human fetal vas deferens epithelial cells

Using the patch-clamp technique, we have identified a large, outwardly rectifying, Cl--selective whole-cell current in primary cultures of human vas deferens epithelial cells. Whole-cell currents were time- and voltage-dependent and displayed inactivation following depolarising pulses >/= 60 mV. Currents were equally permeable to bromide (PBr/PCl = 1.05 +/- 0.04), iodide (PI/PCl = 1. 06 +/- 0.07) and Cl-, but significantly less permeable to gluconate (PGluc /PCl = 0.23 +/- 0.03). Currents spontaneously increased with time after establishing a whole-cell recording, but could be inhibited by exposure to a hypertonic bath solution which reduced inward currents by 68 +/- 4%. Subsequent exposure of the cells to a hypotonic bath solution led to a 418 +/- 110% increase in inward current, indicating that these currents are regulated by osmolarity. 4,4'-Diisothiocyanatostilbene-2,2'-disulphonic acid (100 microM) produced a rapid and reversible voltage-dependent block (60 +/- 5% and 10 +/- 7% inhibition of current, measured at +/- 60 mV, respectively). Dideoxyforskolin (50 microM) also reduced the volume-sensitive Cl- current, but with a much slower time course, by 41 +/- 13% and 32 +/- 16% (measured at +/- 60 mV, respectively). Tamoxifen (10 microM) had no effect on the whole-cell Cl- current. These results suggest that vas deferens epithelial cells possess a volume-sensitive Cl- conductance which has biophysical and pharmacological properties broadly similar to volume-sensitive Cl- currents previously described in a variety of cell types.

Development of nerves containing nitric oxide synthase in the human male urogenital organs

OBJECTIVE

To determine the spatial and temporal distribution of nitric oxide synthase (NOS) in the urogenital organs of a series of human male fetuses, using an immunohistochemical technique.

MATERIAL AND METHODS

Thirteen pre-natal specimens ranging in gestational age from 13 to 30 weeks were acquired following abortion or miscarriage. The distribution of NOS, which catalyses the production of nitric oxide (NO), was revealed using an indirect immunolabelling technique and compared with the overall innervation of each specimen visualized using the general nerve-marker protein gene product 9.5 (PGP).

RESULTS

At 13 weeks of gestation the majority of nerves supplying the developing prostate gland expressed NOS while similar nerves formed a very minor proportion of the total innervation to the urinary bladder and intramural ureters. With increasing gestational age, NOS-containing nerves became more numerous in the lower urinary tract, the majority occurring at the bladder neck and around the prostatic urethra. In contrast, NOS-containing nerves were not detected in the muscle coat of the vas deferens and seminal vesicle until 23 weeks of gestation and at 30 weeks still only formed a small proportion of the intramuscular nerves. From 23 weeks onwards NOS-containing nerves were present occasionally in the dense subepithelial nerve plexuses which developed in the bladder, prostate, vas deferens and seminal vesicle. Also from 23 weeks onwards, many of the epithelial cells lining the vas deferens, seminal vesicle and ejaculatory ducts showed immunoreactivity to NOS but no immunoreactivity was observed in the epithelial lining of the urinary bladder and the intramural ureters.

CONCLUSION

Based on the comparative density of NOS-containing nerves and the difference in their temporal development among the various urogenital organs it is apparent that NO plays an increasingly important role in the autonomic control of the lower urinary tract during fetal development but that its involvement in the functional control of the vas deferens and seminal vesicle is relatively minor before birth.

Developmental pattern and regulation by androgens of androgen receptor expression in the urogenital tract of the rat

Distribution and regulation of androgen receptor expression during fetal and neonatal virilization of the rat fetus was assessed by immunohistochemistry. In mesonephric duct derivatives the androgen receptor expression became evident first in the efferent ductules and epididymis (on fetal day 14), subsequently in the vas deferens and finally in the seminal vesicle. Mesenchymal cells of the urogenital tubercle were positive for androgen receptors from fetal day 14 onwards. In the mesenchymal cells of the prostate anlagen, androgen receptor positive cells were found first on fetal day 16. Administration of 5alpha-dihydrotestosterone to pregnant rats from day 11 to day 20 of gestation caused a stabilization of the wolffian duct in female fetuses. The androgen receptor expression pattern became similar as found in mail fetuses, and showed an increase in density and in frequency of androgen receptor positive cells. Administration of the androgen antagonist flutamide during the same interval caused a reduction in density and frequency of androgen receptor positive cells in male fetuses. These findings indicate that androgens enhance the expression of androgen receptors in the developing rat genital tract by induction of androgen receptor positive cells, and by increasing the frequency. The developmental pattern of androgen receptor expression in the rat mesonephric duct system reflects the androgen-responsiveness of the ducts, and is consistent with induction of the androgen receptor along the ducts by testosterone reaching these structures in an exocrine fashion.

Development of peptide-containing nerves in the human fetal vas deferens and seminal vesicle

OBJECTIVE

To use immunohistochemical methods to study the developing autonomic innervation of the human fetal vas deferens and seminal vesicle.

MATERIAL AND METHODS

Thirteen pre-natal specimens ranging in gestational age from 13 to 30 weeks were acquired following abortion or miscarriage. The overall innervation of each specimen was visualized using protein gene product 9.5 (PGP), a general nerve marker, while the onset and development of specific neuropeptide-containing sub-populations were investigated using antisera to neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), substance P (SP), calcitonin gene related peptide (CGRP), bombesin (BOM), somatostatin (SOM), and met-enkephalin (ENK). In addition the occurrence and distribution of presumptive noradrenergic nerves was studied using antisera to dopamine-beta-hydroxylase (D beta H) and tyrosine hydroxylase (TH).

RESULTS

At 13 weeks numerous PGP, D beta H, TH, NPY and ENK immunoreactive (-IR) nerve trunks were present in the adventitia of the vas deferens and seminal vesicle but at this stage nerve fibres were not present in the smooth muscle coat of either organ. By 17 weeks, fine PGP-, D beta H, and TH-IR nerve fibres had penetrated the outer aspect of the muscle coat of the seminal vesicle but not the vas deferens. At 20 weeks a branching network of PGP-, D beta H- and TH-IR nerve fibres occurred throughout the full thickness of the muscle coat of the seminal vesicle while similar nerves were present only in the outer half of the muscle coat of the vas deferens. At 23 weeks the full thickness of the muscle coat of the vas deferens was richly innervated by a branching plexus of PGP-IR nerves. Many of these adventitial and intramuscular nerves were immunoreactive for D beta H or TH while some were immunoreactive for either NPY or ENK. Occasional adventitial nerves were immunoreactive for SP or CGRP, these being first observed at 20 weeks. VIP-IR nerves were extremely rare in the muscle coat of either organ, being first observed at 17 weeks in the seminal vesicle and at 20 weeks in the vas deferens where they mainly formed perivascular plexuses. PGP-IR nerves were first observed in the submucosa of the seminal vesicle at 20 weeks and in the vas deferens at 21 weeks. Some of these nerves were perivascular in location while other formed a subepithelial plexus which increased in density with increasing gestational age. At 22 weeks of gestation some of the submucosal nerves were immunoreactive for SP or NPY, while at 30 weeks NPY-IR nerves formed the majority of subepithelial nerves. Occasional VIP-IR subepithelial nerves were first observed at 26 weeks but were extremely rare even at 30 weeks. Submucosal nerves immunoreactive for CGRP, D beta H, TH or ENK did not occur in any of the specimens examined.

CONCLUSION

(i) From 13 weeks gestation autonomic nerves develop in the muscle coat of the fetal seminal vesicle and vas deferens, being denser in the seminal vesicle than the vas deferens up to 23 weeks gestation. (ii) The majority of the intramuscular nerves in either organ contain D beta H, TH, NPY and ENK and are presumably noradrenergic in type. (iii) A subepithelial nerve plexus develops around 20 weeks gestation and contains NPY but not VIP, unlike the adult organs. (iv) Scattered neuroendocrine cells immunoreactive for SOM are present in the mucosa of the seminal vesicle from 23 weeks of gestation.

Developmental changes in methylation of spermatogenesis-specific genes include reprogramming in the epididymis

We have determined the status of DNA methylation at specific sites in three spermatogenesis-specific genes, Pgk-2, ApoA1 and Oct-3/4, throughout the development and differentiation of male germ cells in the mouse. We observed a specific demethylation event in the Pgk-2 gene in prospermatogonia at about the time of birth, about 10 days before the onset of transcription which first occurs in primary spermatocytes. All three genes were unmethylated in adult spermatogenic cells in the testis, but were remethylated in mature spermatozoa in the vas deferens. Surprisingly, we found that this remethylation is part of the process of sperm maturation which occurs in the epididymis.

Changes in the peritoneum during the development of the testis, epididymis and ductus deferens in the pig

The development of the peritoneal folds of the testis, epididymis and ductus deferens of the pig prior to testicular descent was studied in 18 to 82 days-old embryos/fetuses. The parietal attachment of the mesonephros, mesonephric and paramesonephric ducts and gubernaculum constituted the urogenital mesentery. This could be divided in a cranial and a caudal part. The first fixed the mesonephros and had a mesogonad as a secondary fold. The second had two branches, one laterally to the umbilical artery belonging to the gubernaculum (Plica gubernacularis) and the medial to the artery contained the meso- and paramesonephric ducts. The mesogonad was related caudally with Plica gubernacularis. The fold of the meso- and paramesonephric ducts could also be divided in two parts. The caudal was a primary component of the urogenital mesentery, while the cranial was first ventral and later lateral to the mesogonad (mesorchium) and appeared as a secondary fold of the urogenital mesentery (cranial part). A vascular fold contributed to separate the suspensory ligament of the testis from the developing mesorchium. The proposed meaning of the terms used might be useful for comparative studies.

True duplication of the vas deferens

We report true duplication of the vas deferens found at routine inguinal hernia repair. This rarity is described in the context of the embryologic model for other vas abnormalities.

Comparison of the effects of the 5 alpha-reductase inhibitor finasteride and the antiandrogen flutamide on prostate and genital differentiation: dose-response studies

Studies were performed to compare the effects of 5 alpha-reductase inhibition and antiandrogen receptor blockade on differentiation of male internal and external genital structures and prostate in the rat. Dose-response studies were performed on male rats treated in utero during the period of sexual differentiation with either the potent 5 alpha-reductase inhibitor finasteride or the antiandrogen flutamide. The treated animals were raised to adulthood and killed, and genital structures were evaluated. Treatment with the 5 alpha-reductase inhibitor finasteride at a dose of 25 mg/kg.day resulted in significant feminization of the external genitalia. There was no further feminization of the genitalia at doses up to 300 mg/kg.day. Wolffian ductal differentiation occurred at all doses evaluated. Seminal vesicle weight, however, significantly decreased at 25 mg/kg.day, but without a further decrease at higher doses of the 5 alpha-reductase inhibitor. Vas deferens and epididymal weights were unchanged at all doses evaluated. There was a significant decrease in prostate size at 25 and 50 mg/kg.day, with no further decrease at higher doses. In flutamide-treated animals, complete feminization of the genitalia occurred at 24 mg/kg.day in all animals. At 18 mg/kg.day, Wolffian ductal differentiation occurred, but seminal vesicle weight was decreased. At dosages of 100, 200, and 300 mg/kg.day flutamide, the vas deferens was absent unilaterally or bilaterally, with small remnants of epididymal head and tail present. At dosages of 24 mg/kg.day and above, the prostate was absent. Studies with the 5 alpha-reductase inhibitor finasteride demonstrate the dependency of prostate and male external genital differentiation on dihydrotestosterone (DHT). However, unlike androgen receptor blockade with flutamide, finasteride did not totally abolish prostate differentiation or completely feminize the external genitalia, despite increasingly higher doses. Since there is no evidence of multiple 5 alpha-reductase isoenzymes to date in the rat, these results suggest that testosterone (T) can compensate for DHT to some degree at the level of the androgen receptor. Wolffian differentiation, however, was not affected by inhibition of DHT, demonstrating its T dependency, but seminal vesicle growth was impaired. Thus, inhibition of 5 alpha-reductase activity limits seminal growth potential in adulthood. Studies with the antiandrogen flutamide show that at doses significantly above that required to completely block prostate differentiation and cause genital feminization, Wolffian ductal differentiation is significantly impaired. Thus, higher doses of flutamide are needed to block the paracrine effect of T on the Wolffian ducts.

Ectopia of the vas deferens into the ureter. Case report and review of the literature

Ectopia of the vas deferens into the ureter is a rare occurrence, frequently associated with anorectal anomalies. To date, 20 cases have been reported, accounting for a total of 26 vasoureteral communications, 6 of which are bilateral. Embryologically, ureteral ectopia of the vas deferens may be explained by an underlying defect in the proximal mesonephric duct or an abnormally cranial origin of the ureteric bud. We add the case of a newborn with an ectopic vas terminating into the ureter of a multicystic kidney.

Ectopia of the vas deferens

Ectopic location of the vas deferens is a rare congenital abnormality that has a spectrum of presentations. Such cases have been associated with anorectal anomalies. Knowledge of distal Wolffian duct embryology may help to explain the developmental steps involved in these anomalies, as well as provide theories for the variations that may be encountered. Vas deferens development is reviewed, and two cases of vas ectopia are presented to illustrate and lend support to current theories of normal and abnormal vasal embryology.

Embryonal remnants in inguinal hernia sacs

Inguinal herniorrhaphy is the most common general surgical procedure performed on the neonate or young pediatric patient. The vas deferens and epididymis are vulnerable to damage, including transection during inguinal exploration or hernia repair. Occasionally the surgical pathologist encounters glandular or tubular epithelial-lined structures in hernia sac tissue. Significant medicolegal implications arise when embryonal remnants are mistakenly identified as true vas deferens or epididymis. This study evaluates the incidence and morphology of these embryonal remnants in hernia sacs from patients of The Children's Hospital, Denver, CO. Embryonal remnants were found in 1.5% of 599 hernia sacs from 427 consecutively operated males aged 37 weeks gestation to 19 years. True vas deferens and epididymis were each identified once for an incidence of 0.33%. The remnants resemble either vas deferens or epididymis. The average remnant diameter is 0.17 mm, and did not change significantly with age. Remnants are surrounded by varying amounts of condensed mesenchyme, trichrome-negative for muscle. The testes and vasa differentia from 32 autopsy cases, ranging in age from 26 weeks gestation to 7 years of age, were used to evaluate normal development and morphology of the vas deferens, epididymis and embryonal remnants. The vas deferens is well developed by 26 weeks gestation. The surrounding smooth-muscle coat does not stain with trichrome until 32 weeks gestation. The vas deferens increases in diameter in a linear fashion during gestation, and continues to increase in diameter in the postnatal period. The vas deferens at 4 months of age is 1.2 to 1.4 mm in diameter; this is also the age of highest incidence of bilateral herniorrhaphies and presence of remnants.

Ductal epithelial cells cultured from human foetal epididymis and vas deferens: relevance to sterility in cystic fibrosis

A tissue culture system for epithelial cells derived from male human foetal genital ducts has been established. The cells show morphological and biochemical characteristics of ductal epithelial cells, and can be passaged and maintained in culture for considerable periods of time. These cells will provide a suitable system for investigating, by electrophysiological, biochemical and molecular biological methods, the cause of sterility in cystic fibrosis.

The presence of a caput epididymidis in congenital absence of the vas deferens

Experience with 2 patients stimulated a review of the literature on congenital absence of the vas deferens in 133 cases. Bilateral absence was more common and occurred in 80 per cent of the cases, and a caput epididymidis was said to be present in at least 88 per cent. Information concerning the epididymis was lacking in 8.9 per cent of the cases. Two probable explanations for this common clinical finding are offered. Embryologic studies have shown that the caput, unlike the rest of the epididymis, can develop from genital ridge derivatives mainly. This clinical-embryological consideration refutes the common belief that the vas deferens and epididymis as a whole are of mesonephric duct origin. A second, independent factor is the selective blood supply of the caput in some cases. In these cases the caput is preserved by a branch of the testicular artery, perforating the tunica albuginea from within outwards, instead of a branch of the spermatic artery originating from the extratesticular portion of the testicular artery.

Absent vas deferens in association with renal abnormalities

Absence of the vas deferens, especially if unilateral, should alert the clinician to an underlying renal anomaly, and further urological investigation is mandatory. If the vas is shown to be bilaterally absent in an infant, cystic fibrosis should be excluded. In the context of vasectomy, exploration of the palpably absent side should be unnecessary if intravenous urography detects a combined anomaly, although post-operative seminal analysis will still need to be performed.

The embryologic origin of the caput epididymidis in the rat

The ACI rat with its known incidence of ipsilateral agenesis of the kidney and ductus deferens provides an excellent mammalian model for the study of the embryologic origin or the caput epididymidis. Because a portion of the caput epididymidis remains in these affected animals, it seems to be derived from the mesonephric tubules rather than the mesonephric duct in the rat. Histochemical assays also support the common origin of both the ductuli efferentes and caput epididymidis from the mesonephric tubules.

Chronic guanethidine treatment of female rats including effects on the fetus

Adult virgin female rats were injected daily with low doses (5 or 10 mg/kg) or a high dose (30 mg/kg) of guanethidine for 12 or 18 weeks respectively. 'Short' and 'long' noradrenergic neurones were unaffected by low doeses. This contrasts markedly to earlier findings in male rats in which long-term damage of 'short' noradrenergic neurones occurred, and indicates a basic difference between 'short' noradrenergic neurones in male and female rats. Widespread degeneration of both types of neurones followed treatment with high doses and little reinnervation was observed 8 weeks after cessation of treatment. Fertility, pregnancy and litter size were apparently unaffected. Some teratogenic effects were observed in the offspring of female rats treated with guanethidine (10 or 25 mg/kg/day) before and throughout pregnancy. However, these effects had largely disappeared by the time the offspring were 10 weeks old. Since noradrenergic neurones of newborn rats are particularly sensitive to damage by guanethidine it would appear that either very little guanethidine crosses the placental barrier or that noradrenergic neurones are not susceptible during prenatal development to the cytotoxic effects of guanethidine.

The role of the epididymis in descensus testis and the topographical relationship between the testis and epididymis from the sixth month of pregnancy until immediately after birth

The position of the testis, the relationship between the epididymis and the testis, as well as the development and regression of the gubernaculum were investigated in 18 testicles of children from the 26th week of pregnancy until a few weeks after birth. The most important role in descensus testiculorum is ascribed to the differentiation of the epididymis and the ductus deferens. It is androgen dependent. The testis descends in the processus vaginalis, being attached to its dorsal wall.

Congenital vas deferens--ureteral connection

Congenital drainage of the vas deferens into a ureter permits retrograde passage of urine through the vas to the epididymis. If this anomaly is accompanied by urinary tract pathology with vesicoureteral reflux, hydroureter, stasis, and infection, the passage of urine into the vas can very well lead to epididymitis of a chronic or recurring nature and secondary scrotal abscesses. Two cases of this rare anomalous connection are presented in which such scrotal infections occurred. The diagnosis should be suspected on clinical grounds and can be confirmed by cystograms in which the dye refluxes up the ureter and passes into the vas. The association of rectal anomalies is of embryologic significance and may be additionally important clinically by further suggesting the possibility of the ureteral-vas anomaly.

Alterations in the developmental properties of stroma during the development of the urogenital ridge into ductus deferens and uterus in embryonic and neonatal mice

The ability of mesenchyme from the urogenital ridge to participate in the development of male and female urogenital organs was studied by preparing homo- and heterotypic recombinants of epithelium and stroma from ductus deferens and uterus of neonatal mice. The recombinants as well as intact 14-day old embryonic urogenital ridges (URG) were grown for two to eight weeks in adult male and female hosts. The development of ductus deferens and seminal vesicle from female UGR's grafted into male hosts and uterus from male UGR's grafted into female hosts demonstrate that the mesenchyme of embryonic UGR's is capable of participating in the development of either male or female urogenital structures. During normal development of the female urogenital tract, the bisexual morphogenetic potentiality of UGR mesenchyme persists postnatally as demonstrated by the ability of uterine stroma to support normal differentiation of epithelium of ductus deferens in male hosts. Conversely, during the normal development of the male urogenital tract, the morphogenetic potentiality of mesenchyme of the urogenital ridge is restricted as stroma from the ductus deferens appears incapable of participating in uterine morphogenesis in male or female hosts. These differences in the developmental properties of UGR stroma may be attributed to differences in hormonal conditions in male and female fetuses.

Significance of absent vas deferens at hernia repair in infants and children

An absent vas deferens may be associated with unilateral renal agenesis or undiagnosed cystic fibrosis. Such patients should be further evaluated with a sweat chloride and intravenous pyelogram. The finding of absent vas deferens during exploration for an undescended testis does not provide absolute evidence for absence of the testis, since these structures have independent embryologic origins.