Activins, follistatin and immunoregulation in the epididymis.

BACKGROUND: The interface between the epididymis and the immune system is implicated in many male reproductive pathologies. The resident immune cell populations and immune-environment within the epididymis are significantly different from the testis, which is an immune-privileged site. Moreover, the immune cell subsets and immunological responses between different regions of the epididymis vary considerably. The cauda epididymis is more susceptible to autoimmune responses than the caput in rodent models of active immunization or suppressed immune tolerance, and in men with congenital or physical damage to the reproductive tract. Activins are members of the transforming growth factor-ß family of cytokines that are crucial for testis and epididymal development; however, they also have complex immunoregulatory properties and may play an essential role in the regulation of immunity in the reproductive tract. MATERIALS AND METHODS: Our recent research and relevant publications by other researchers identified following a PubMed search are reviewed. RESULTS: The caput epididymis displays elevated endogenous expression of activins A and B and the immunoregulatory gene, indoleamine-2,3-dioxygenase, co-existing with an extensive population of intra-epithelial and interstitial macrophages and dendritic cells, which appear to be involved in regulating tolerance against sperm antigens. The caput is also relatively resistant to inflammatory damage caused by autoimmunity or bacterial infection, but the cauda, which exhibits low activin expression and high levels of the activin-binding protein, follistatin, is highly susceptible to inflammatory damage. Paradoxically, inflammation in the cauda induces increased activin production, and inhibition of activin activity reduces inflammatory responses. Studies using mouse models with altered levels of activins and follistatin indicate a relationship between the activins and genes involved in inflammation and immunoregulation. CONCLUSION: The existing data indicate that activins play a complex role in controlling inflammation and immunity in the epididymis and vas deferens.

Long-term study of vasectomy in Macaca radiata--histological and ultrasonographic analysis of testis and duct system.

This study was aimed to investigate the long-term effect of vasectomy using the bonnet monkey (Macaca radiata) as a primate animal model. Animals weighing around 6 to 8 kg were randomly chosen for bilateral, unilateral vasectomy and sham-control. The postoperative periods of six months and two years were considered as short and long-term, respectively. Sperm were collected and subjected to analysis before euthanasia. The testes and epididymides were excised from euthanized animals then embedded in paraffin. Normal histological changes were observed in sham-operated animals and short-term contralateral testes. In contrast, marked alterations were observed in the testes and epididymides of both short and long-term groups. Seminiferous epithelium was thinned out showing marked depletion of germ cells in long-term; only a thin layer of Sertoli cells, spermatogonia, and fewer spermatocytes were seen. Exfoliation of germ cells and the occurrence of multinucleated giant cells were common features in these tubules. The epididymal tubular lumens were greatly dilated with accumulated spermatozoa in short and long-term animals; significant defects were observed in the epithelium of the long-term animals. Microscopic spermatic granulomas were noticed in epididymides and the vas deferens. Large granulomas were seen in long-term vasectomized monkeys, frequently compressing the surrounding structures. These granulomas could be visualized in ultrasound, however, only at the late stage of its occurrence. Sperm collected from the unilateral vasectomized animals showed a poor motility score in the capillary mucus penetration test (CMPT). Results indicate that the changes observed after vasectomy might be due to pressure initially, whereas in the long-term the damage was supplemented by autoimmune attack. With immunoglobulin (IgG) deposition in contra-lateral unoperated testis of unilateral vasectomized animals it also showed degenerative changes and a concomitant drop in sperm quality. Although, granulomatous reactions were observed in the epididymis and vas deferens but testes were spared from such reactions even in the long-term.

Immunophysiology and pathology of inflammation in the testis and epididymis.

The ability of spermatogenic cells to evade the host immune system and the ability of systemic inflammation to inhibit male reproductive function represent two of the most intriguing conundrums of male reproduction. Clearly, an understanding of the underlying immunology of the male reproductive tract is crucial to resolving these superficially incompatible observations. One important consideration must be the very different immunological environments of the testis, where sperm develop, and the epididymis, where sperm mature and are stored. Compared with the elaborate blood-testis barrier, the tight junctions of the epididymis are much less effective. Unlike the seminiferous epithelium, immune cells are commonly observed within the epithelium, and can even be found within the lumen, of the epididymis. Crucially, there is little evidence for extended allograft survival (immune privilege) in the epididymis, as it exists in the testis, and the epididymis is much more susceptible to loss of immune tolerance. Moreover, the incidence of epididymitis is considerably greater than that of orchitis in humans, and susceptibility to sperm antibody formation after damage to the epididymis or vas deferens increases with increasing distance of the damage from the testis. Although we still know relatively little about testicular immunity, we know less about the interactions between the epididymis and the immune system. Given that the epididymis appears to be more susceptible to inflammation and immune reactions than the testis, and thereby represents the weaker link in protecting developing sperm from the immune system, it is probably time this imbalance in knowledge was addressed.

Experimental model of autoimmune orchitis with abdominal placement of donor's testes, epididymides, and vasa deferentia in recipient mice.

Haploid germ cells (spermatids and spermatozoa) develop in the testis after immune tolerance has been established. Therefore, they contain various autoimmunogenic antigens, but the testis is known to be an immunologically privileged organ. In particular, the blood-testis barrier formed by Sertoli cells protects autoimmunogenic haploid germ cells from attack by the autoimmune system. Experimental autoimmune orchitis (EAO), a breakdown of the testicular immune privilege leading to immunological male infertility, has been ordinarily induced in mice by immunization twice with testicular antigens+complete Freund's adjuvant (CFA)+Bordetella pertussis (BP). We previously found that two subcutaneous injections of viable syngeneic testicular germ cells induced murine EAO without the use of CFA+BP. In both EAO models, the lesions are characterized by spermatogenic disturbance with lymphocytic inflammation, and a second immunization with testicular antigens is critical for the disease induction. In the present study, we found that only one placement of a syngeneic donor's testes, epididymides and vasa deferentia (TEV) into the abdominal cavity or subcutaneous space was sufficient to induce EAO on the recipient's testes in mice. It was also noted that the placement of TEV induced only orchitis without epididymo-vasitis, while the serum autoantibodies were reactive with haploid germ cells existing throughout the TEV. Furthermore, the TEV placed in the abdominal cavity rather than the subcutaneous space was effective in inducing severe EAO, and the A/J strain was most susceptible to the TEV-induced EAO among the three strains examined. The model of EAO induced by the placement of the donor's TEV into the abdominal cavity in A/J mice will be helpful for the further analyses of testicular autoimmunity.

Inmunohistoquímica de la inervación del conducto deferente humano / Immunohistochemistry in the innervations of the human vas deferens

El conducto deferente humano presenta una pared muscular gruesa, donde el componente muscular liso ocupa la parte media y más prominente. Esta composición histológica le permite al órgano desarrollar las potentes contracciones durante el proceso de la eyaculación y emisión del semen. Objetivos: Analizar la presencia y distribución de la positividad inmunohistoquímica a Neurofilamentos (NF) en las paredes del conducto deferente humano. Pacientes, Materiales y Método: De tres pacientes sometidos a orquiectomía radical por diagnóstico de Seminoma, se obtuvieron los conductos deferentes fijados en formol tamponado (pH 7,2). Mediante procedimientos histológicos de rutina, se obtuvieron secciones de 5 um de espesor en portaobjetos silanizados. Se procedió al desarrollo del protocolo de inmunohistoquímica usando anticuerpos específicos contra Neurofilamentos (NF); las imágenes se obtuvieron con cámara fotográfica digital CCD Micrometrics, en microscopio óptico Olympus CX31. Resultados: En los subcompartimientos de las secciones transversales de la pared de los conductos deferentes humanos, se observa la reacción inmunohistoquímica positiva a NF. Sin embargo, los fascículos nerviosos se concentran en la adventicia, mientras que en la mucosa y pared muscular son en extremo escasos y finos. Conclusión: En el conducto deferente existe una inervación preferencial dispuesta en la adventicia del órgano, siendo posible que la potencia de la contracción de la pared en base a la actividad muscular, requiera factores adicionales de estimulación.

The human vas deferens has a thick muscular wall, where the smooth muscle component occupies the middle and most prominent. This composition allows the organ histologic develop powerful contractions during ejaculation process and the semen. Objectives. To analyze the presence and distribution of immunologically positlve for Neurofilament (NF) on the walls of human vas deferens. Patients, Materiall and Methods.' Three patients undergoing radical orchiectomy for seminoma diagnosis were obtained vas deferens fixed in buffered formain (pH 12). By routine histological procedures, sections were obtained 5 um thick on silylated slides. We proceeded to the development of immunohistochemical protocol using specific antibodies against Neurofilament (NF); the digitized images were obtained with CCO Micrometrics digital camera, in the light microscope Olympus CX31. Results: In the subcompartments of the cross sections of the wall of human vas deferens, there is a positive immunohistochemical reaction to NF However, nerve bundles are concentrated in the adventitia, whereas in the mucosa and muscle wall are extremely rare and fine. Conclusion: In the vas deferens there willing preferential innervation in the adventitia of the court, it being possible for the power of contraction of the wall of the body based on muscle activity, stimulation requires additional factors.

Identification and characterization of an antigen recognized by monoclonal antibody TRA 54 in mouse epididymis and vas deferens.

Spermatozoa in testicular fluid are known to have weak forward motility and cannot fertilize eggs. The epididymis is known to participate in sperm maturation leading fertilization, but little is known about the specific epididymal molecules involved in the modification of sperm. In this study, we characterized the new pattern of expression of an antigen previously identified in testicular germ cells by monoclonal antibody (mAb) TRA 54. This antigen is expressed in epididymal and vas deferens epithelial cells in mice older than 24 days but not during younger developmental stages. Evaluation by immunohistochemistry shows that antigen expression is limited to the cytoplasm of a specific cell population of epithelia along the epididymal regions and vas deferens of adult mice. The molecules synthesized and released by epididymal and vas deferens epithelia into their lumen seem to bind on spermatozoa moving down through the ducts. Immunoblot analysis showed that the molecules recognized by mAb TRA 54 in testis and epididymis were similar and share a common epitope involving carbohydrate domains. Interestingly, the antigens identified in epididymal and vas deferens epithelial cells were expressed independently of testicular germ cells and are produced in an androgen-dependent manner. Finally, the molecules recognized by mAb TRA 54 seem to play an important role in spermatogenesis, as well as in epididymal function related to spermatozoa maturation and ability to fertilize.

Role of anti-calcium channel and anti-receptor autoantibodies in autonomic dysfunction in Sjögren's syndrome.

Auto-antibodies cross-reacting with L-type voltage-gated calcium channels (VGCCs) have been described in primary Sjögren's syndrome (pSS), and may mediate the cardiac defects in neonates born to mothers with pSS. L-type VGCCs are also present in autonomically innervated tissues. Therefore, the aim of this project was to investigate a role for anti-VGCC antibodies and antibodies to alpha(1)-adrenoceptors or P(2X)-purinoceptors in the autonomic dysfunction that occurs in pSS. Contraction of the sympathetically innervated vas deferens in response to stimulation of the muscle by an alpha(1)-adrenoceptor agonist (phenylephrine) or a P(2X)-purinoceptor agonist (alpha,beta-methylene ATP) was measured in the absence and presence of 2% serum. Contractions produced by phenylephrine and by alpha,beta-methylene ATP were abolished by nicardipine, demonstrating that they are coupled to calcium influx through L-type VGCCs. Serum from patients with pSS or from healthy controls did not significantly alter the L-type channel-dependent responses of smooth muscle to agonist stimulation. We therefore conclude that pSS serum does not contain autoantibodies that functionally inhibit L-type VGCCs, alpha(1)-adrenoceptors or P(2X)-purinoceptors in smooth muscle and that such autoantibodies cannot explain the autonomic dysfunction in pSS.

Cytotoxic phenotype of intra-epithelial lymphocytes in normal and cryptorchid human testicular excurrent ducts.

BACKGROUND: Most testicular and epididymal lymphocytes express T-cell markers, but their cytotoxic potential and activation status have not been reported. In this study, distribution of the cytotoxic cells was compared between normal and cryptorchid testes stratified into two groups: the first with complete absence of germ cells [Sertoli cell-only (SCO)] and the second with arrested spermatogenesis (SCA). METHODS: Immunohistochemistry for the T-lymphocyte marker CD3 and cytotoxic markers CD8, TIA-1 and granzyme B was performed on paraffin-embedded sections. RESULTS: The number of CD8+ and CD3+ intra-epithelial lymphocytes (IELs) increased distally throughout the normal epididymis. TIA-1 immunostaining revealed that a significant proportion of IELs exhibited cytotoxic potential, whereas granzyme B staining disclosed a subpopulation of activated cytotoxic lymphocytes (CTLs). TIA-1/CD8 and granzyme B/CD8 double immunostaining revealed that the vast majority of TIA-1+ and granzyme B+ cells were CD8+. The proportion of activated granzyme B+ lymphocytes increased distally throughout the normal epididymis. The number of TIA-1+ and granzyme B+ intra-epithelial and stromal lymphocytes was significantly increased in the normal as opposed to the SCO cryptorchid epididymis and proximal vas deferens. CONCLUSIONS: These results suggest that exposure of the testicular excurrent ducts to spermatozoa or immature germ cells triggers the activation and recruitment of CTLs. Cytotoxic granule effector mechanisms may contribute to the immunological barrier preventing the immune response to spermatozoa in testicular ducts.

Antisperm autoantibody response is reduced by early repair of a severed vas deferens in the juvenile rat.

OBJECTIVE: To determine whether antisperm autoantibody production after prepubertal vas injury is influenced by immediate repair of the vas compared to delay of the reanastomosis until sexual maturity. DESIGN: Animal study comparing early repair, late repair, and sham-operated groups. SETTING: Research laboratory in a medical school. PATIENT(S): Lewis rats. INTERVENTION(S): After division of the vas deferens in juvenile rats, animals in an early repair group had the vasa repaired immediately by using an absorbable intraluminal stent. Animals in a late repair group had vasa obstructed by ligation until after puberty, when they underwent microsurgical vasovasostomy (age 60 days). MAIN OUTCOME MEASURE(S): Antisperm antibodies were assayed by ELISA. The weights of reproductive organs were determined, and samples of testis were studied by light microscopy. RESULT(S): The antisperm antibody response was less when the vas was repaired immediately than if the repair was delayed until after puberty. There was a low incidence of testicular alteration in the repair groups and none in sham-operated animals. CONCLUSION(S): If the vas deferens is injured or obstructed prepubertally, there may be a benefit to considering immediate repair to reduce the likelihood of developing antisperm autoantibodies, which have been associated with reduced fertility.

Immunohistochemical localization of epididymal secretory glycoprotein EP1 in the adult male chimpanzee.

Proteins, synthesized by the epididymal epithelium, are secreted sequentially into the lumen of the ducts epididymis where they effect sperm maturation and enable functional motility and fertilizing capacity. EP1 is a major secretory glycoprotein of chimpanzee (Pan troglodytes) epididymis. The epididymal duct exhibits diverse histology (Smithwick & Young, 1997). Epithelia I-V of the efferent ducts show no characteristic anti-EP1 binding. The densest granules of anti-EP1 reaction product appear in epithelium VI adjacent to the basal lamina in the infranuclear region of the principal cells (PCs), in the cytoplasm of the apical half of the PCs, and in the perinuclear and perivacuolar cytoplasm of the basal cells. In epithelia VII-XIV of the ductus epididymis proper, anti-EP1 binding decreases distally and is localized in the cytoplasm of the PCs and basal cells, among the stereocilia of the luminal border, within various microvillar borders, and in the luminal fluid. Therefore, EP1 appears to be synthesized and secreted primarily in the caput region of the ductus epididymis and may be reabsorbed nonselectively across epithelia with apical microvilli, including the non-ciliated cells of efferent ducts, the distal corpus and cauda of the ductus epididymis, and the proximal ductus deferens.

Autoimmune orchitis, epididymitis, and vasitis are immunogenetically distinct lesions.

Experimental allergic orchitis (EAO), the principle animal model of noninfectious testicular inflammatory disease, is a genetically determined phenotype. Classical EAO, induced by inoculation with testicular homogenate and the appropriate adjuvants, is characterized by inflammatory infiltrates in the testis (orchitis), epididymis (epididymitis), and vas deferens (vasitis). In this study, the genetic control of susceptibility and resistance to these three lesions was analyzed in the mouse. The results obtained with independent inbred strains and H2 congenic mice show that the genetic control of all three lesions is complex and involves both H2 and non-H2-linked genes. Whole-genome exclusion mapping was performed on a backcross population segregating for all three phenotypes. Permutation-derived thresholds provided experimentwise, chromosomewise, comparisonwise, and marker-specific chromosomewise thresholds for declaration of significant regions linked to marker loci. Unique loci were identified on chromosome 8 for orchitis, chromosome 16 for epididymitis, and chromosome 1 for vasitis and have been designated as Orch6, Epd1, and Vas1, respectively. These results show that autoimmune orchitis, epididymitis, and vasitis are immunogenetically distinct lesions.

Changes in resting membrane potential induced by active sensitization in the guinea-pig vas deferens.

Smooth muscles hyperresponsiveness is a common feature in anaphylaxis and allergic diseases. The aim of the present work was to investigate whether the enhanced reactivity of sensitized guinea-pig vas deferens was associated with changes in the resting membrane potential (Er) of the smooth muscle cells. Active sensitization was performed by subcutaneous injection of egg albumen. Er was measured in vitro in isolated vas deferens with conventional KCl-filled microelectrodes. Quantification of [3H]ouabain binding sites, measurements of 86Rb efflux, and measurements of Na and K contents were also performed. In normal physiological solution, at 35 degrees C, Er was a mean of -54.1+/-0.3 mV (mean +/- SEM) in control vas deferens. Sensitization resulted in depolarizing Er by about 7 mV. In control and sensitized preparations, the 3H-ouabain binding site concentration, the efflux of 86Rb, and the K content were similar. In guinea-pig vas deferens, active sensitization induced a partial depolarization of the resting membrane potential of the smooth muscle cells, which did not result from a downregulation of Na+ -K+ pump sites.

Appearance of 'natural' antisperm autoantibodies after sexual maturation of normal Lewis rats.

Serum antisperm antibodies were assessed quantitatively with an ELISA in normal male Lewis rats at intervals between ages 10 and 128 days, spanning the onset of puberty. Antisperm antibodies rose between 56 and 91 days, and were significantly higher in 91- and 128-day old rats than at earlier intervals. The animals underwent normal pubertal development as indicated by increases in weights of the seminal vesicles and ventral prostate. The rise in antisperm antibodies correlated temporally with events in the postnatal development of the male reproductive system, with the increase in antisperm antibodies most closely following the time when spermatozoa reach the epididymis and proximal vas deferens at approximately 56 days. The observation that serum antisperm antibodies increased only after sexual maturation suggests that some differentiation antigens of sperm are processed and presented to the immune system under normal circumstances in this strain. Western blot analysis showed that the sera from normal postpubertal Lewis rats bound several proteins, including bands of > 100, 82-75, 78, 68, 65, 63, 54-55, 42, 37, 35, 26, and 20-22 kDa. The majority of these autoantibodies were sperm-specific as shown by the absence of comigrating bands in western blots of somatic tissue extracts, although antibodies in postpubertal sera recognized certain other proteins in somatic tissues. Several protein autoantigens, defined by sera from postpubertal animals, matched dominant autoantigens recognized by antibodies produced in response to vasectomy, prepubertal vas obstruction, or immunization with spermatozoa. This finding indicates that the antisperm antibody responses following sperm immunization, vasectomy or prepubertal vasal obstruction represent accentuation of an autoantibody response to sperm that develops normally following puberty.

Effect of guinea-pig purified immunoglobulin G1 on the responsiveness of tracheal, aortic, vas deferens and ileum smooth muscles.

BACKGROUND: Smooth muscles hyperresponsiveness is a common feature in anaphylaxis and allergic diseases. OBJECTIVE: The aim of the present work was to investigate the effect of in vitro passive sensitization with highly purified immunoglobulin G1 (IgG1) on the responsiveness of tracheal, aortic, vas deferens and ileum smooth muscles. METHODS: Firstly, IgG1, obtained from actively sensitized BFA guinea-pigs, was purified by Protein A-Sepharose column and characterized by enzyme-linked immunosorbent assay (ELISA) and immunoelectrophoresis analysis. Concentration-response curves to spasmogens (acetylcholine for trachea and vas deferens, noradrenaline for aorta and histamine for ileum) were established before and after in vitro passive sensitization with IgG1. RESULTS: Contractile responses and maximal contractions were significantly enhanced after passive sensitization for all the organs. Maximal contractions were significantly increased in the trachea (+46.7%), aorta (+51%), vas deferens (+114.2%) and ileum (+117.2%). At the end of the experiments, the application of the sensitizing antigen induced a significant Schultz-Dale reaction of the smooth muscles. CONCLUSION: The present results show that the in vitro application of purified IgG1 can produce non-specific smooth muscle hyperreactivity and hypersensitivity. So, IgG1 can be considered as the main factor involved in the genesis of sensitization-induced hyperresponsiveness, and probably play a great role in hyperreactivity observed during allergic diseases and anaphylaxis.

Subcellular localization of synaptophysin in noradrenergic nerve terminals: a biochemical and morphological study.

The subcellular localization of synaptophysin was investigated in noradrenergic nerve terminals of bovine vas deferens and dog spleen and compared with membrane-bound and soluble markers of noradrenergic storage vesicles. At the light microscopical level chromogranin A- and cytochrome b561-immunoreactivity revealed an identical and very dense innervation of the entire vas deferens. In the case of synaptophysin, most immunoreactivity was found only in the outmost varicosities closest to the lumen, which were also positive for chromogranin A. Small dense-core vesicles of dog spleen were purified using a combination of velocity gradient centrifugation and size exclusion chromatography. Small dense-core vesicles were enriched 64 times as measured by the noradrenaline content. Enrichments for dopamine-beta-hydroxylase were in a similar range. Synaptophysin-containing vesicles were smaller in size and they did not contain the typical noradrenergic markers dopamine-beta-hydroxylase, cytochrome b561, and noradrenaline. Instead, they might store adenosine triphosphate (ATP). A greater part of synaptophysin immunoreactivity was consistently found at high sucrose densities at the position of large dense-core vesicles. We conclude that in the noradrenergic nerve terminal: (1) small dense-core vesicles have a membrane composition similar to large dense-core vesicles, indicating that the former are derived from the latter, and (2) synaptophysin seems not to be present on small dense-core vesicles. We suggest the possibility that synaptophysin-containing vesicles form a residual population whose role in neurotransmission has been taken over by large and small dense-core vesicles following noradrenergic differentiation.

The immunopathology of unilateral vasectomy in the ram.

This study investigated the relationship between the local (spermatic granuloma) and systemic events after unilateral vasectomy in six rams. Spermatic microgranulomas were first observed at 4 weeks post vasectomy (PV), at which time lymphocytes, chiefly CD4+ (helper/inducer) cells, were incorporated into the periphery of the phagocytic wall. Although plasma cells accumulated around blood vessels near these early granulomas, they were not incorporated into them. All sectioned vas deferens contained additional microscopic spermatic granulomas away from the point of sectioning, as did one-third of cauda epididymides on the vasectomised side. There were significant (P < 0.001) increases in T-lymphocytes, especially CD4 cells and plasma cells (chiefly IgG-containing) within the granulomas at each successive PV interval. Concurrent enzyme-linked immunosorbent assay indicated initial presence of IgG and IgM antisperm antibody in serum between 2 and 4 weeks PV. There were significant increases of IgG (P < 0.01) and IgM (P < 0.001) throughout the experiment but IgA antisperm antibody was negligible.

The use of a seminal vesicle specific protein (MHS-5 antigen) for diagnosis of agenesis of vas deferens and seminal vesicles in azoospermic men.

Azoospermia is the cause of infertility in 8% of infertile male patients. Ten percent of those patients suffer from agenesis of the seminal vesicle (SV) and vas deferens (VD) agenesis. Currently, the diagnosis of SV and VD agenesis is based on low semen volume, low pH, and low fructose content of the seminal fluid of azoospermic men who have normal serum gonadotropins. In this study, an SV-specific sperm-coating antigen, the MHS-5 antigen, was used as a marker for the presence of SVs. The SV-specific protein (SVSP), MHS-5, was present in the control group but was not found in any of the seven samples from azoospermic men with proven agenesis of SV and VD. Another semen component, the prostate-specific antigen (PSA), whose presence in the semen is not influenced by the SV and VD agenesis, was found in both the study and the control groups. Its presence ruled out the possibility of azoospermia due to ejaculatory duct obstruction. The absence of MHS-5 antigen in seminal fluid can be used as a tool for a reliable diagnosis of agenesis of SV and VD in azoospermic men.

Enhancement of the responsiveness of vas deferens and ileum smooth muscle in sensitized guinea pigs: in vitro study.

Changes in the reactivity of the ileum (to histamine and barium chloride) and vas deferens (to acetylcholine and barium chloride), isolated from actively egg albumen-sensitized guinea pigs, have been investigated. The study was performed on 2 guinea pig strains: the Dunkin-Hartley strain, usually used as an airway allergic model, and the BFA strain. In actively sensitized guinea pigs of both strains, concentration-response curves exhibited a significant dose-dependent upward shift compared to those obtained in control guinea pigs. The maximal contraction strength calculated from these curves was significantly enhanced in both sensitized guinea pig strains, without a change in EC50 values. This study showed that the active antigen sensitization procedure involved several smooth muscle functions, and not exclusively the trachea.

Secretory immune system of the male reproductive tract: effects of dihydrotestosterone and estradiol on IgA and secretory component levels.

Immunoglobulin A (IgA) is present at mucosal sites of the body which are exposed to the external environment. In this study we evaluated the levels of IgA and its transport protein secretory component (SC) in organs of the male reproductive tract of both intact and castrate-hormone-treated rats. Our goals were to determine whether these proteins are present in the male reproductive tract and whether sex hormones can influence the amounts of IgA and SC in selected organs. We found that in intact animals, IgA was present in the prostate, epididymis, vas deferens and testis and that SC levels in the prostate were 22-fold greater than in these same organs. Dihydrotestosterone (DHT) and/or estradiol, when administered to castrate animals, dramatically increased the levels of prostatic SC. In contrast, the levels of IgA were only minimally affected. DHT administration also resulted in a significant increase in SC found in the seminal vesicles. These studies demonstrate that IgA and SC are present in the male reproductive tract of the rat. Further, they show that androgens and estrogens act at selected sites in the male reproductive tract to play an important role in maintaining SC levels and thereby suggest that these hormones influence the movement of IgA from tissues into secretions.

Induction of immunity to spermatozoa in male domestic fowl and effects on fertility.

Male fowl were immunized intravenously (i.v.) or intramuscularly (i.m.) with spermatozoa to assess the effects of immunity to spermatozoa on fertility. Histological and immunofluorescence evaluations of testis and ductus deferens tissues after 24 weeks of immunizations revealed immune cell infiltration and immunoglobulin associated with spermatozoa. The long-term immunization regimen resulted in significant antisperm antibody titres in the immunized groups. When semen from i.v.-immunized males was used to inseminate females, fertility over 7 days was reduced (P less than 0.05). A subsequent experiment using a 10-week i.v. immunization scheme also led to high antisperm titres. Spermatozoa from these males were characterized by lower fertility and duration of fertility than those of controls (P less than 0.05). As in mammals, a reduction in fertility may result from exposure of avian males to sperm antigens.