α-Adrenoceptor assays

α-Adrenoceptors mediate responses to activation of both peripheral sympathetic nerves and central noradrenergic neurons. They also serve as autoreceptors that modulate the release of norepinephrine (NE) and other neurotransmitters. There are two major classes of α-adrenoceptors, the α(1)- and α(2). Each class is subdivided into three subtypes: α(1A), α(1B), α(1D), and α(2A), α(2B), α(2C). Described in this unit are in vitro isolated tissue methods used to study α-adrenoceptor functions and to identify novel ligands for these receptors. Detailed protocols describing use of isolated tissues to study the various α(1)- and α(2)-adrenoceptor subtypes are provided.

Establishment of a polyclonal antibody against the retinoid X receptor of the rock shell Thais clavigera and its application to rock shell tissues for imposex research

In the chain of study to further elucidate the role of retinoid X receptor (RXR) in the development of imposex caused by organotin compounds in gastropod mollusks, we established a polyclonal antibody against RXR of the rock shell Thais clavigera. Immunoblotting demonstrated that this antibody could recognize T. clavigera RXR. In males and imposex-exhibiting females, immunohistochemical staining with the antibody revealed nuclear localization of RXR protein in the epithelial and smooth muscle cells of the vas deferens and in the interstitial and epidermal cells of the penis. These results suggest that the polyclonal antibody against T. clavigera RXR can specifically recognize RXR protein in tissues of T. clavigera and therefore is useful for evaluating RXR protein localization. Furthermore, RXR may be involved in the induction of male-type genitalia (penis and vas deferens) in normal male and organotin-exposed female rock shells.

Immunohistochemical expression of connexin 43 and occludin in the rat testis after epididymal and vasal ligation

OBJECTIVE

To describe the effects of epididymal and vasal ligation, in an experimental rat model, by using connexin 43 and occludin immunohistochemistry as well as transmission electron microscopy.

DESIGN

Comparative and controlled experimental research study.

SETTING

University animal research and histology laboratories in Turkey.

ANIMAL(S)

Wistar male rats in experimental and control groups.

INTERVENTION(S)

The control group underwent sham operation (n = 7). The first experimental group (n = 7) underwent unilateral epididymal ligation, whereas the second experimental group (n = 7) underwent unilateral vasal ligation to induce experimental epididymal and vasal obstruction models, respectively. All animals were then killed at 90 days.

MAIN OUTCOME MEASURE(S)

Immunohistochemical expression of connexin 43 and occludin for testicular tissues was determined after epididymal and vasal obstruction models. Ultrastructural morphological changes were examined by electron microscopy.

RESULT(S)

Results of the semiquantitative analysis revealed that expressions of both occludin and connexin 43 in the rat testis were decreased in the experimental groups compared with in the sham-operated group. However, changes after vasal ligation were more prominent. Ultrastructural examination confirmed decreased intercellular communication as well as increased cellular degeneration among the ipsilateral and contralateral testicular tissues.

CONCLUSION(S)

Immunohistochemical expression of occludin and connexin 43 were decreased in the testis after vasal and epididymal ligation when compared with the sham-operated group. Ultrastructural changes indicating cell degeneration were more prominent after vasal ligation.

Relaxin family peptide receptors Rxfp1 and Rxfp2: mapping of the mRNA and protein distribution in the reproductive tract of the male rat

BACKGROUND

Relaxin is the endogenous ligand of the G-protein coupled receptor RXFP1, previously known as LGR7. In humans relaxin can also activate, but with lower affinity, the closely related receptor for the insulin-like peptide from Leydig cells, RXFP2, previously known as LGR8. The lack of relaxin impairs male fertility but the precise distribution and the function of relaxin receptors in the male reproductive tract is not known. We investigated the distribution of Rxfp1 and Rxfp2 in the reproductive tract of the male rat and the function of relaxin in the vas deferens, a tissue with high expression of both receptors.

METHODS

The presence of mRNA for Rxfp1 and Rxfp2 was investigated in testes, cultured Sertoli cells, epididymis, vas deferens, seminal vesicle, prostate, and spermatozoa by RT-PCR and Southern blot. Protein expression in the testis, vas deferens, primary culture of Sertoli cells, and spermatozoa was assessed by immunohistochemistry and immunofluorescence. The role of relaxin in the vas deferens was evaluated by contractility studies and radioimmunoassay of cAMP production. The effect of relaxin on mRNA levels for metalloproteinase-7 was measured by Northern blot.

RESULTS

Transcripts for Rxfp1 and Rxfp2 were present in almost all parts of the male reproductive tract, with high levels in testis and vas deferens. Both receptors were immunolocalized in late stage germ cells but not in mature spermatozoa, although mRNAs for both receptors were also present in mature spermatozoa. Rxfp1 but not Rxfp2 was detected in cultured Sertoli cells. Strong immunostaining for Rxfp1 and Rxfp2 was seen in muscular and epithelial layers of the vas deferens and in arteriolar walls. Relaxin did not affect contractility and cyclic AMP production of the vas deferens, but increased the levels of mRNA for metalloproteinase-7.

CONCLUSION

Rxfp1 and Rxfp2 are widely and similarly distributed throughout the male reproductive tract. Our results suggest that Rxfp1 on spermatids and Sertoli cells may be important in spermatogenesis. Relaxin in the vas deferens does not affect contractility, but may affect vascular compliance and collagen and matrix remodeling.

Expression of ion transport-associated proteins in human efferent and epididymal ducts

Appropriate intraluminal microenvironment in the epididymis is essential for maturation of sperm. To clarify whether the anion transporters SLC26A2, SLC26A6, SLC26A7, and SLC26A8 might participate in generating this proper intraluminal milieu, we studied the localization of these proteins in the human efferent and the epididymal ducts by immunohistochemistry. In addition, immunohistochemistry of several SLC26-interacting proteins was performed: the Na+/H+exchanger 3 (NHE3), the Cl−channel cystic fibrosis transmembrane conductance regulator (CFTR), the proton pump V-ATPase, their regulator Na+/H+exchanger regulating factor 1 (NHERF-1), and carbonic anhydrase II (CAII). Our results show that SLC26A6, CFTR, NHE3, and NHERF-1 are co-expressed on the apical side of the nonciliated cells, and SLC26A2 appears in the cilia of the ciliated cells in the human efferent ducts. In the epididymal ducts, SLC26A6, CFTR, NHERF-1, CAII, and V-ATPase (B and E subunits) were co-localized to the apical mitochondria rich cells, while SLC26A7 was expressed in a subgroup of basal cells. SLC26A8 was not found in the structures studied. This is the first study describing the localization of SLC26A2, A6 and A7, and NHERF-1 in the efferent and the epididymal ducts. Immunolocalization of human CFTR, NHE3, CAII, and V-ATPase in these structures differs partly from previous reports from rodents. Our findings suggest roles for these proteins in male fertility, either independently or through interaction and reciprocal regulation with co-localized proteins shown to affect fertility, when disrupted.

COX-1 and -2 expressions in sex-related organs of neonatally estrogen-treated rats and in activated and nonactivated macrophage RAW264.7 cells with phytoestrogen

Cyclooxygenase (COX)-2 is an inducible isoform, expressed in inflamed leukocytes and cancer cells. It is known that estrogen causes prostate dysplasia, but little is known about COX-2 expression and its influence on male reproductivity. In this study, we show that COX-2 was abolished in the distal end of the vas deferens in neonatally estrogenized (diethylstilbestrol, NeoDES) Sprague-Dawley (SD) rats at age of 15 mo, but the control normal rats were found to remain constitutive expression at the same age, while the levels of COX-1 in these rats remained intact. Furthermore, BAX, an indicator of sperm quality, was observed in the endothelium of vas deferens and sperm of the aged rats. However, COX-2 was not detected in the inflamed lesions of NeoDES rat's prostate by immunohistochemistry. In addition to estrogen, hydroxymatairesinol (HMR), a phytoestrogen, was analyzed in vitro for possible regulation on COX-2. Through Western blot analysis, HMR was shown to have no inhibitory affect on COX-2 expression. These results indicated that estrogen treatment strongly influences the expression of COX-2 that is associated with fertility, but no induction of COX-2 by estrogen may not exclude COX-2's role in prostatitis, and the anti-tumor mechanism of HMR largely remains elusive.

Saw palmetto is an indirectly acting sympathomimetic in the rat-isolated prostate gland

BACKGROUND

To investigate whether saw palmetto that inhibits alpha1-adrenoceptor binding in vitro affects contractility of the rat prostate gland.

METHODS

The effects of a commercially available saw palmetto extract were examined on the contractility of rat-isolated prostate glands. The extract was tested in the presence and absence of phentolamine, prazosin, yohimbine, propranolol, hexamethonium, cocaine, desipramine, nifedipine, guanethidine, atropine, and alpha,beta-methylene ATP to evaluate the mechanism of action. Isolated preparations of rat vas deferens and bladder were used for comparison.

RESULTS

Unexpectedly, saw palmetto extract caused contractions of the rat prostate gland that could be attenuated by prazosin, phentolamine, nifedipine, guanethidine, cocaine, and desipramine but not by any of the other pharmacological tools. Similar contractile effects were observed in rat-isolated vas deferens preparations but not in rat-isolated bladder preparations.

CONCLUSIONS

In the rat prostate gland, saw palmetto extract causes indirect alpha1-adrenoceptor-mediated contractions via the release of noradrenaline from sympathetic neurons.

Characterization and Localization of Cysteine-Rich Secretory Protein 3 (CRISP-3) in the Human Male Reproductive Tract

Mammalian members of the cysteine-rich secretory protein (CRISP) family are expressed predominantly in the male reproductive tract and are implicated in the process of reproduction from spermiogenesis, posttesticular sperm maturation, and capacitation to oocyte-sperm fusion, and possibly also penetration of the zona pellucida. Rodents express only 2 CRISPs (CRISP-1 and CRISP-2) in their male reproductive system, whereas humans and horses express an additional third member named CRISP-3. We have previously demonstrated that this protein is present in human seminal plasma as well as in other exocrine secretions, in blood plasma, and in neutrophilic granulocytes. To characterize the protein in seminal plasma and localize the production of CRISP-3 in the human male reproductive tract, we performed immunoblotting and enzyme-linked immunosorbent assay measurements of seminal plasma and immunohistochemistry and in situ hybridization of tissue specimens. We were able to show that human CRISP-3 is a quantitatively minor seminal plasma protein not associated with prostasomes. Furthermore, CRISP-3 expression was found in the secretory epithelium throughout the male genital tract, with particularly high expression in the cauda epididymis and ampulla vas deferens. Examination of seminal plasma from vasectomized males indicates that organs downstream of the epididymis are probably the major sources of seminal plasma CRISP-3.

Gelatinases and serine proteinase inhibitors of seminal plasma and the reproductive tract of turkey (Meleagris gallopavo)

This study examined proteolytic enzymes and serine proteinase inhibitors in turkey seminal plasma with relation to their distribution within the reproductive tract and to yellow semen syndrome (YSS). Proteases of blood plasma, extracts from the reproductive tract, and seminal plasma were analyzed by gelatin zymography. We found a clear regional distribution of proteolytic enzymes in the turkey reproductive tract. Each part was characterized by a unique profile of serine proteolytic enzymes of molecular weights ranging from 29 to 88 kDa. The ductus deferens was found to be a site of very intense proteolytic activity. Two metalloproteases of 58 and 66 kDa were detected in all parts of the reproductive tract and seminal plasma. Using electrophoretic methods for detection of anti-trypsin activity, we found three serine proteinase inhibitors in turkey seminal plasma. Two inhibitors were found in the testis and epididymis and a third in the ductus deferens and seminal plasma. Blood plasma was characterized by the presence of two metalloproteinases and one serine proteinase inhibitor (of low migration rate) that were also detected in the reproductive tract. Amidase and anti-trypsin activities (expressed per gram of protein) differed for yellow and white seminal plasma. We concluded that turkey seminal plasma contains metalloproteases, serine proteinases, and serine proteinase inhibitors. The metalloproteases and one proteinase inhibitor are related to blood proteinases but the other two inhibitors and serine proteinases seem to be unique for the reproductive tract.

Antispermatogenic and hormonal effects of Crotalaria juncea Linn. seed extracts in male mice

AIM

To evaluate the antifertility activity of various extracts of Crotalaria juncea seeds in male mice.

METHODS

Adult male mice were gavaged the petroleum ether, benzene and ethanol extracts of C. juncea seeds, 25 mg x (100g)(-1) x day(-1) for 30 days. On day 31 the animals were sacrificed by cervical dislocation and the testes, epididymis, vas deferens, seminal vesicles, prostate gland, bulbourethral gland and levator ani were dissected out and weighed. The organs were processed for biochemical and histological examination.

RESULTS

In petroleum ether, benzene and ethanol extracts treated rats, there was a decrease in the weights of testis and accessory reproductive organs. The diameters of the testis and seminiferous tubules were decreased. Spermatogonia, spermatocytes and spermatids in the testis and the sperm count in cauda epididymis were also decreased. There was a significant reduction in the protein and glycogen contents and an increase in the cholesterol content in the testis, epididymis and vas deferens. Of the 3 extracts, the ethanol extract appeared to be the most potent in antispermatogenic activity. When the ethanol extract was tested in immature male mice, there was an antiandrogenic effect as the weights of accessory organs were reduced.

CONCLUSION

The various extracts of C. juncea seeds arrest spermatogenesis and are likely to have an antiandrogenic activity.

Neonatal coadministration of testosterone with diethylstilbestrol prevents diethylstilbestrol induction of most reproductive tract abnormalities in male rats

The primary purpose of this study was to evaluate whether the coadministration of testosterone (TE; 200 micro g) with 10 micro g of diethylstilbestrol (DES) between days 2 and 12 postnatally could prevent the adverse gross reproductive tract changes and associated loss of androgen receptor (AR) expression induced by DES treatment alone. Various endpoints (rete testis area, efferent duct lumen area, epithelial cell height of efferent ducts, and vas deferens) were quantified to check for the abnormal changes that have been shown to occur after neonatal treatment with a high dose (10 micro g) of DES. Additionally, DES induction of an aberrant pattern of estrogen receptor alpha (ER-alpha) immunoexpression in the vas deferens and seminal vesicles was evaluated. The coadministration of DES with TE prevented the induction of all but one of the abnormalities induced by DES treatment on its own, coincident with the restoration of normal/supranormal TE levels and normal immunoexpression of the AR and ER-alpha in the tissues studied. The exception was DES-induced lumenal distension of the efferent ducts, which was only partially prevented by the coadministration of DES with TE. These evaluations were made on day 18, but the described abnormalities were already somewhat evident by day 8 in DES-treated animals. It was therefore tested whether a delay of TE replacement until days 8-12 was still able to reverse the abnormalities already induced by DES treatment alone. A delayed treatment with TE reversed the adverse changes in epithelial cell height and in ER-alpha and AR immunoexpression in the same tissues by day 18; however, rete testis overgrowth was only partially prevented, and efferent duct distension was not prevented at all. These results provide further evidence that DES-induced disorders of reproductive tract development in the male result from a disturbance of the androgen-estrogen balance rather than from estrogen action alone.

Investigation of postjunctional alpha1- and alpha2-adrenoceptor subtypes in vas deferens from wild-type and alpha(2A/D)-adrenoceptor knockout mice

1. The subtypes of alpha(1)- and alpha(2)-adrenoceptor mediating contractions of vas deferens have been examined in wild-type and alpha(2A/D)-adrenoceptor knockout mice. 2. Maximum contractions to noradrenaline but not phenylephrine were significantly greater in vas from wild-type. The alpha(1A)-adrenoceptor antagonist RS100329 (5-methyl-3-[3-[4-[2-(2,2,2,-trifluoroethoxy)phenyl]-1-piperazinyl]propyl]-2,4-(1H)-pyrimidinedione) (10 nM) significantly shifted the potency of noradrenaline. The alpha(2D)-adrenoceptor antagonist BRL 44408 (2-[(4,5-dihydro-1H-imidazol-2-yl)methyl]-2,3-dihydro-1-methyl-1H-isoindole) significantly reduced the maximum contraction to noradrenaline in wild-type but not in knockout. 3. Following prazosin (0.1 micro M), a component of the contraction to noradrenaline in wild-type but not in knockout was sensitive to the alpha(2)-adrenoceptor antagonist yohimbine. 4. Nifedipine (10 micro M) or suramin (100 micro M) reduced the contraction to 10 Hz stimulation for 4 s to an early peak and small maintained response. The peak was abolished by the alpha(1)-adrenoceptor antagonist prazosin. 5. RS100329 or prazosin inhibited 10 Hz stimulation evoked contractions with a U-shaped concentration-response curve: inhibiting responses up to 0.1 micro M, with a reversal of inhibition above this concentration. In the presence of suramin or nifedipine, the reversal of inhibition by high concentrations of prazosin was reduced. 6. The alpha(1D)-adrenoceptor selective antagonist BMY7378 (8-[2-(4-(2- methoxyphenyl)piperazin-1-yl)ethyl]-8-azaspiro[4,5]decane-7,9-dione) produced inhibition of 10 Hz evoked contractions only in high concentrations. 7. In conclusion, contractions to nerve stimulation in mouse vas deferens involve largely alpha(1A)-adrenoceptors and purinoceptors. alpha(1)-Adrenoceptor antagonists in high concentrations increase the purinergic response presumably by blocking prejunctional alpha(2)-adrenoceptor-mediated inhibition. In the presence of nifedipine, responses are predominantly alpha(1)-adrenoceptor mediated. Contractions to exogenous noradrenaline involved both alpha(1A)- and alpha(2A/D)-adrenoceptors in wild-type mice.

A regulated interaction of syntaxin 1A with the antidepressant-sensitive norepinephrine transporter establishes catecholamine clearance capacity

Norepinephrine (NE) transporters (NETs) terminate noradrenergic synaptic transmission and represent a major therapeutic target for antidepressant medications. NETs and related transporters are under intrinsic regulation by receptor and kinase-linked pathways, and clarification of these pathways may suggest candidates for the development of novel therapeutic approaches. Syntaxin 1A, a presynaptic soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein, interacts with NET and modulates NET intrinsic activity. NETs colocalize with and bind to syntaxin 1A in both native preparations and heterologous systems. Protein kinase C activation disrupts surface NET/syntaxin 1A interactions and downregulates NET activity in a syntaxin-dependent manner. Syntaxin 1A binds the NH(2) terminal domain of NET, and a deletion of this domain both eliminates NET/syntaxin 1A associations and prevents phorbol ester-triggered NET downregulation. Whereas syntaxin 1A supports the surface trafficking of NET proteins, its direct interaction with NET limits transporter catalytic function. These two contradictory roles of syntaxin 1A on NET appear to be linked and reveal a dynamic cycle of interactions that allow for the coordinated control between NE release and reuptake.

Isoforms of angiotensin I-converting enzyme in the development and differentiation of human testis and epididymis

Angiotensin I-converting enzyme (ACE; CD143, Kininase II, EC 3.4.15.1) is known to be crucial for male fertility in animal models. We therefore studied its testicular (tACE) and somatic (sACE) isoforms in foetal and adult human testis and epididymis using monoclonal antibodies and cRNA probes. During spermatogenesis, tACE was found only in differentiating germ cells and was the only isoform within the seminiferous tubules of adult men. Although tACE mRNA was present in spermatocytes, tACE protein was initially found in post-meiotic step 3 spermatids and increased markedly during further differentiation. The enzyme was strictly confined to the adluminal membrane site of elongating spermatids and was localized at the neck and midpiece region of released and ejaculated spermatozoa. In contrast, sACE was expressed heterogeneously in Leydig cells and endothelial cells of the testicular interstitium, and homogeneously along the luminal surface of epithelial cells lining the ductuli efferents, corpus and cauda of epididymis, and vas deferens. The cell- and site-restricted pattern of sACE corresponded to that found in foetal tissues except an additional and transient expression of sACE in foetal germ cells and foetal Sertoli cells. Our study documents for the first time in humans the regulation and unique cellular distribution of ACE isoforms during the ontogenesis of the lower male genital tract.

Regional differences in the adenosine A(2) receptor-mediated modulation of contractions in rat vas deferens

Adenosine receptors involved in modulation of contractions were characterized in the bisected rat vas deferens by combining pharmacological and immunohistochemical approaches. In both portions, noradrenaline-elicited contractions were enhanced by the adenosine A(1) receptor agonist N(6)-cyclopentyladenosine (CPA), and inhibited by the non-selective adenosine receptor agonist 5'-N-ethylcarboxamidoadenosine (NECA) in the presence of the adenosine A(1) receptor antagonist 1,3-dipropyl-8-cyclopentyl-l,3-dipropylxanthine (DPCPX). The adenosine A(2A) receptor agonist 2-p-(2-carboxyethyl)phenethyl-amino-5'-N-ethylcarboxamidoadenosine (CGS 21680) also inhibited noradrenaline-elicited contractions but only in the prostatic portion. Contractions elicited by the stable ATP analogue alpha,beta-methyleneATP (alpha,beta-MeATP) were inhibited only by NECA in the presence of DPCPX and only in the prostatic portion. This study provides functional evidence for the presence, in both portions of the rat vas deferens, of an adenosine A(1) receptor-mediated enhancement and of an adenosine A(2) receptor-mediated inhibition of contractions. The latter effect is mediated by both A(2A) and A(2B) subtypes in the prostatic portion but only by the A(2B) subtype in the epididymal portion. This regional variation is supported by the immunohistochemical results that revealed an adenosine A(2A) receptor immunoreactivity not co-localized with nerve fibres more abundant in the prostatic than in the epididymal portion.

Azadirachta indica adversely affects sperm parameters and fructose levels in vas deferens fluid of albino rats

Azadirachta indica treatment for 24 days in albino rats resulted in a decrease in the total sperm count, sperm motility, and forward velocity in vas deferens fluid. The percentage of abnormal sperm increased and the fructose content decreased. As diminished levels of fructose parallel androgen deficiency, we conclude that reduced androgen levels resulting from the anti-androgenic property of A. indica leaves probably influences the physiological maturation of sperm.

Stimulation of hypoxia-inducible factor-1 alpha (HIF-1alpha) protein in the adult rat testis following ischemic injury occurs without an increase in HIF-1alpha messenger RNA expression

Hypoxia-inducible factor 1 (HIF-1) is a transcription factor composed of alpha and beta subunits. Stabilized from proteasome degradation and activated by hypoxia, HIF-1 stimulates expression of hypoxia-sensitive genes that mediate oxygen homeostasis in many tissues. Our hypothesis is that HIF-1 is involved in the cellular response to hypoxia in the ischemic testis. Goals of this study were to determine if HIF-1alpha mRNA is expressed in the testis, epididymis, and accessory sex glands of adult Sprague-Dawley rats and to determine if HIF-1alpha mRNA and protein expression in the testis is affected by experimentally induced ischemia. Total RNA from reproductive organs of adult rats was analyzed by relative reverse transcription-polymerase chain reaction (RT-PCR) analysis. HIF-1alpha mRNA showed equal expression in testis, all segments of epididymis, ductus deferens, accessory sex glands, and penis. To examine the effects of ischemia on HIF-1alpha mRNA and protein expression in the testis, rats were subjected to unilateral testicular ischemia by placing a ligature around spermatic artery or ischemia-inducing experimental torsion and reperfusion. RT-PCR revealed that HIF-1alpha mRNA expression at all times of ischemic treatment and reperfusion was unchanged compared with normoxic controls. HIF-1alpha protein was detected by immunoblot analysis of nuclear protein extracts from normoxic testes. Steady-state levels of HIF-1alpha protein were stimulated by 15 min of ischemia and showed a 2-fold increase at 30 min and 1, 3, and 6 h. HIF-1alpha protein was also elevated by experimental torsion and reperfusion compared with normoxic controls. These results support the hypothesis that HIF-1 may play a role in the cellular response to hypoxia in the ischemic testis.

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.

Differential expression of estrogen receptors alpha and beta in the reproductive tracts of adult male dogs and cats

Expression of estrogen receptors (ERs) in the reproductive tracts of adult male dogs and cats has not been reported. In the present study, ERalpha and ERbeta were localized by immunohistochemistry using ER-specific antibodies. ERalpha was found in interstitial cells and peritubular myoid cells in the dog testis, but only in interstitial cells of the cat. In rete testis of the dog, epithelial cells were positive for ERalpha staining, but in the cat, rete testis epithelium was only weakly positive. In efferent ductules of the dog, both ciliated and nonciliated cells stained intensely positive. In the cat, ciliated epithelial cells were less stained than nonciliated epithelial cells. Epithelial cells in dog epididymis and vas deferens were negative for ERalpha. In the cat, except for the initial region of caput epididymis, ERalpha staining was positive in the epithelial cells of epididymis and vas deferens. Multiple cell types of dog and cat testes stained positive for ERbeta. In rete testis and efferent ductules, epithelial cells were weakly positive for ERbeta. Most epithelial cells of the epididymis and vas deferens exhibited a strong positive staining in both species. In addition, double staining was used to demonstrate colocalization of both ERalpha and ERbeta in efferent ductules of both species. The specificity of antibodies was demonstrated by Western blot analysis. This study reveals a differential localization of ERalpha and ERbeta in male dog and cat reproductive tracts, demonstrating more intensive expression of ERbeta than ERalpha. However, as in other species, the efferent ductules remained the region of highest concentration of ERalpha.

Monoclonal antibodies, immunofluorometric assay, and detection of human semenogelin in male reproductive tract: no association with in vitro fertilizing capacity of sperm

Semenogelin plays an important role in sperm clotting and is degraded into smaller fragments by prostate-specific antigen (PSA) during clot liquefaction. Semenogelin and its fragments inhibit sperm motility in vitro. We studied the expression of semenogelin I mRNA and its localization in various tissues of the male genital tract. We also studied semenogelin concentrations with respect to sperm parameters and the outcome of in vitro fertilization. Semenogelin protein was detected by immunohistochemical staining and semenogelin I mRNA was detected by Northern blot analysis in the seminal vesicles and ampullary part of the vas deferens, whereas specimens from the prostate, epididymis, testis, and the female genital tract were negative. Using monoclonal antibodies against semenogelin, an immunofluorometric assay was developed to measure semenogelin levels in seminal plasma and to evaluate possible correlations with sperm parameters and fertilization in vitro. No correlation was found between the semenogelin concentration and the volume of the ejaculate, sperm concentration, sperm motility, or in vitro fertilization rate. Semenogelin levels were positively correlated with the total protein concentration in seminal plasma, and there was an inverse correlation between the concentration of semenogelin and that of PSA. The levels of semenogelin appear to bear no relationship to the in vitro fertilization capacity of the spermatozoa.

Immunohistochemical study of androgenic gland hormone: localization in the male reproductive system and species specificity in the terrestrial isopods

Androgenic gland hormone (AGH) is responsible for male sexual differentiation in crustaceans. AGH of the terrestrial isopod, Armadillidium vulgare, is a heterodimetric glycoprotein. To determine the distribution of AGH in the male reproductive system, an immunohistochemical study was carried out using antibodies raised against different components of the proAGH molecule of A. vulgare, for example, the whole molecule of recombinant proAGH expressed in Escherichia coli (E. coli-rAGH), the N-terminal nonapeptide of the B chain, and the N-terminal octapeptide of the A chain. The androgenic gland (AG) showed strong immunoreactivity to all three of these antibodies, while the testis, the seminal vesicle, and the vas deferens did not show immunostaining. To examine the species specificity of AGH, the male reproductive systems in nine species of Oniscidea were examined immunohistochemically with antibody raised against E. coli-rAGH. A positive reaction was observed in the AGs of species belonging to the Armadillidiidae, Porcellionidae, and Scyphacidae families. Immunoreactivity was strongest in A. vulgare and was stronger in Armadillidiidae than in Porcellionidae or in Scyphacidae. These results suggest that structural similarity of AGH may exist among some terrestrial isopods, although AGH seems to harbor a relatively high degree of species specificity.

Function and localization of oxytocin receptors in the reproductive tissue of rams

Oxytocin is present in the male reproductive tract and has been shown to increase contractility in the epididymis and to modulate steroidogenesis. This study investigated the effects of oxytocin in the testis in vivo, and the presence and cellular localization of oxytocin receptors in the reproductive tract of rams. During the breeding season, mature rams underwent efferent duct ligation before injection of either oxytocin (20 microg) or oxytocin plus an oxytocin antagonist (20 microg) into the testicular artery; the contralateral testicular artery received saline. Injection of oxytocin caused a significant increase (P < 0.05) in the concentration of spermatozoa collected from the rete testis. This effect was not observed after treatment with the oxytocin antagonist plus oxytocin. Western blot analysis performed using a specific oxytocin receptor antibody (020) identified a single immunoreactive band of 66 kDa in testicular and epididymal tissue. This band was present in uterine tissue but not in liver or muscle. Immunocytochemistry identified oxytocin receptors on Leydig and Sertoli cells of the testis, on epithelial cells throughout the epididymis, on peritubular smooth muscle cells in the cauda epididymidis, and on the epithelial cells and circular smooth muscle layer of the ductus deferens. These findings indicate that oxytocin can modulate sperm transport in the ram testis. A role for oxytocin in promoting sperm transit is supported by the localization of oxytocin receptors in the cauda epididymis and ductus deferens, and the presence of receptors on Leydig, Sertoli and epididymal epithelial cells provides further evidence that oxytocin may be involved in the local regulation of steroidogenesis.

Identification and characterization of P31m, a novel sperm protein in Cynomolgus monkey (Macaca fascicularis)

We have previously described a hamster sperm glycoprotein, P26h, which is implicated in the cascade of events occurring during the interaction between mature spermatozoa and the oocyte's zona pellucida. The P26h is acquired on the acrosomal cap of the spermatozoon during its maturation arising within the epididymis. Lately, using a polyclonal antiserum raised against P26h, a 34 kDa protein, P34H, has been identified on the acrosomal cap of the human spermatozoon. The cloning and sequencing of the cDNA encoding P34H has revealed a 65% similarity between the P34H and P26h amino acid sequences. Considering that P26h shows total immunocontraceptive properties in the hamster, it is of relevant importance to have an animal model phylogenetically closer to the human. Using the Cynomolgus monkey, we searched for a protein autologous to the human P34H. A 31 kDa protein, the P31m, localized on the acrosomal cap of the monkey spermatozoon has been identified by a Western blot analysis and by immunohistochemical techniques using an anti-hamster P26h antiserum. Northern blot analysis showed increasing high levels of the P31m mRNA through the epididymis and at lower levels in the testis. In situ hybridization showed the presence of the P31m mRNA in the principal cells of the epididymis. The cloning and sequencing of the cDNA encoding the P31m showed a high homology of 97% identity between the P31m and P34H nucleotidic sequences. This study clearly demonstrates that the monkey P31m is the homologous protein of the hamster P26h and of the human P34H. Mol. Reprod. Dev. 59: 431-441, 2001.

Aquaporin 9 expression along the male reproductive tract

Fluid movement across epithelia lining portions of the male reproductive tract is important for modulating the luminal environment in which sperm mature and reside, and for increasing sperm concentration. Some regions of the male reproductive tract express aquaporin (AQP) 1 and/or AQP2, but these transmembrane water channels are not detectable in the epididymis. Therefore, we used a specific antibody to map the cellular distribution of another AQP, AQP9 (which is permeable to water and to some solutes), in the male reproductive tract. AQP9 is enriched on the apical (but not basolateral) membrane of nonciliated cells in the efferent duct and principal cells of the epididymis (rat and human) and vas deferens, where it could play a role in fluid reabsorption. Western blotting revealed a strong 30-kDa band in brush-border membrane vesicles isolated from the epididymis. AQP9 is also expressed in epithelial cells of the prostate and coagulating gland where fluid transport across the epithelium is important for secretory activity. However, it was undetectable in the seminal vesicle, suggesting that an alternative fluid transport pathway may be present in this tissue. Intracellular vesicles in epithelial cells along the reproductive tract were generally poorly stained for AQP9. Furthermore, the apical membrane distribution of AQP9 was unaffected by microtubule disruption. These data suggest that AQP9 is a constitutively inserted apical membrane protein and that its cell-surface expression is not acutely regulated by vesicular trafficking. AQP9 was detectable in the epididymis and vas deferens of 1-wk postnatal rats, but its expression was comparable with adult rats only after 3--4 wk. AQP9 could provide a route via which apical fluid and solute transport occurs in several regions of the male reproductive tract. The heterogeneous and segment-specific expression of AQP9 and other aquaporins along the male reproductive tract shown in this and in our previous studies suggests that fluid reabsorption and secretion in these tissues could be locally modulated by physiological regulation of AQP expression and/or function.

Immunohistochemical localization of estrogen receptor-alpha in sex ducts and gonads of newborn piglets

Estrogen receptor-alpha (ER-alpha) expression in piglet uteri has previously been reported from day 15 after birth. Nevertheless, uterine tissue has been reported to be estrogen sensitive from the day of birth. Since estrogen action in the uterine tissue is suggested to be mediated principally by ER-alpha, the present study aimed to evaluate the presence of ER-alpha in uteri of 1- to 2-day-old piglets by means of immunohistochemistry. In addition, sex ducts and gonads of both sexes were examined. The results clearly demonstrate the presence of ER-alpha immunopositive cells in uterine tissue, which explains its estrogen responsiveness. Immunostaining was most intense in the glandular epithelial cells and is suggested to indicate participation of ER-alpha in adenogenesis. In oviducts, almost all epithelial cells were immunostained moderately positive, while the stroma cells were stained comparably more positive. The functional significance of this intensity difference is uncertain but could indicate that part of the estrogen action on the epithelium is mediated through the stroma cells, as is known for the uterus. In ovaries, the surface epithelium and stroma cells were immunostained, whereas germ and granulosa cells were immunonegative. It is speculated that ER-alpha might be involved in yet unknown intraovarian mechanisms. In male sex ducts, immunostaining was virtually confined to the epithelium of efferent ducts. All cells in the epididymis as well as in vas deferens were immunonegative. The unique presence of ER-alpha in efferent ducts corresponds with localization in other species, where it has been shown to be involved in fluid reabsorption. The obtained data on localization of ER-alpha correspond with the present knowledge, obtained in ER-alpha knockout mice, of the biological function of ER-alpha within male and female gonads and sex ducts.

Comparative study of the molecular and functional expression of L-type Ca2+ channels and large-conductance, Ca2+-activated K+ channels in rabbit aorta and vas deferens smooth muscle

The relationship between the density of ionic currents through major two channels, voltage-dependent L-type Ca2+ channels (L-type VDCC) and large-conductance, Ca2+-activated K+ channels (BKC), and the mRNA expression levels of alpha1C subunit of L-type VDCC (alpha1C) and alpha/beta subunits of BKC (alphaBK/betaBK) were compared in smooth muscle cells (SMC) of rabbit aorta and vas deferens using whole cell-voltage clamp and reverse transcription-polymerase chain reaction (RT-PCR) analyses. The density of the currents through VDCC (ICa) and BKC (IK,Ca) at +10 mV in aortic SMC was approximately one-seventh and one-sixth respectively of that in vas deferens. Whilst application of the Ca2+ channel agonist Bay K 8644 increased ICa by 75-90% in these SMC, the increase in IK,Ca was far greater in aorta than in vas deferens. The expression of the alpha1C transcript in vas deferens was approximately 3.5 times higher than that in aorta. In contrast, expression of alphaBK/betaBK was almost identical in both tissues, indicating the dissociation of IK,Ca density from the expression levels of BKC transcripts in aorta. The results were supported by Western blot and immunocytochemical analyses using subunit-specific antibodies. The lower Ca2+ influx through VDCC in aorta activates only a very limited fraction of BKC compared with that in vas deferens. The greater expression of BKC than of VDCC in aortic SMC contributes to a strong negative feed-back mechanism that minimizes membrane depolarization and acts as a safety margin to maintain low membrane excitability.

Synthesis, absolute configuration and antimuscarinic activity of the enantiomers of [1-(2,2-diphenyl-[1,3]dioxolan-4-yl)-ethyl]-dimethyl-amine

Methylation of the carbon atom C of compound 1, a potent and not selective muscarinic antagonist, was carried out. The resulting diastereomers were separated and the corresponding racemate further resolved to give four enantiomers, which were tested both as hydrogen oxalate and methiodide salts. The pharmacological results obtained at M1, M2 and M3 muscarinic receptor subtypes, show that methylation at C1, depending on the stereochemistry, increases antagonist potency, having thus the same effect of nitrogen quaternization. These results may well lead to the development of new potent antimuscarinic drugs lacking a cationic head.

Pitfalls in the diagnosis of epithelioid sarcoma presenting in an unusual site: a case report

The cytologic appearance of epithelioid sarcoma in fine-needle aspiration biopsy cytology (FNABC) smears has not been extensively described. We report a case of epithelioid sarcoma in a 55-year-old male who presented with nodular swellings in the abdominal wall and scrotum. The scrotal swelling was subsequently demonstrated to arise from the vas deferens. We highlight the cytomorphologic, immunocytochemical, and histopathologic features of this rare lesion in an unusual site, with particular emphasis on the dilemma encountered in the cytodiagnosis of this lesion.

Alpha-azido acids for direct use in solid-phase peptide synthesis

Several new alpha-azido acids have been synthesized and their use in solid-phase peptide synthesis has been demonstrated. The azido group allows for high activation of the carboxyl group as an acid chloride without formation of byproducts and with no detectable racemization. An analog of Leu-enkephalin has been prepared and tested in the mouse vas deferens and guinea pig ileum bioassays: it displays moderate activity at the delta-opiod receptor.

Presence and possible role of the spliced isoform of the P2X1 receptor in rat vascular smooth muscle cells

An alternatively spliced isoform of the P2X1 receptor (P2X1a) was cloned from rat mesenteric artery. The spliced isoform does not have the 27 amino acids that are in the middle of the putative extracellular loop domain of the P2X1 original subunit (P2X1). Reverse transcriptase polymerase chain reaction (RT-PCR) revealed co-localization of P2X1a mRNA and P2X1 mRNA in vascular and other smooth muscle tissues and heart, but not in the spinal cord. In HEK293 cells transfected with P2X1 cDNA, ATP (1 microM) evoked an inward current which strongly desensitized, and an intense signal for GFP (green fluorescent protein) fused with P2X1 was detected at the membrane. Neither of these results was obtained in HEK293 cells expressing P2X1a alone. The fluorescent GFP signal was detected at the membrane when GFP-fused P2X1a was co-expressed with P2X1, and no significant difference in the ATP-activated current was noted between cells expressing P2X1 and those coexpressing P2X1 and P2X1a. These results indicate that the 27-amino-acid sequence (175-201) is important for protein trafficking to the membrane and for the formation of a functional P2X1 receptor. Our results also show that P2X1a is transported to the membrane when P2X1a is co-expressed with P2X1, although the co-expression of P2X1a does not modify the channel's current properties.

Identification of ADAM 31: a protein expressed in Leydig cells and specialized epithelia

A family of proteins containing a disintegrin and metalloproteinase domain (ADAMs) has been identified recently. Here, we report the identification of a novel member of the ADAM protein family from mouse. This protein is designated ADAM 31. The complementary DNA sequence of ADAM 31 predicts a transmembrane protein with metalloproteinase, disintegrin, cysteine-rich, and cytoplasmic domains. Messenger RNA encoding ADAM 31 was most abundant in testes, but was also detected in many other tissues. More significantly, the antibodies raised against ADAM 31 reveal that the protein has a unique and restricted expression pattern. ADAM 31 is expressed in Leydig cells of the testes, but unlike many other ADAMs, it is not found on developing sperm. Furthermore, ADAM 31 is highly expressed on four types of specialized epithelia: the cauda epididymidis, the vas deferens, the convoluted tubules of the kidney, and the parietal cells of the stomach.

The distribution of vesicular acetylcholine transporter in the human male genitourinary organs and its co-localization with neuropeptide Y and nitric oxide synthase

Because doubt still remains concerning the distribution of nerves that are unequivocally cholinergic in the human genitourinary organs, we have used a specific marker, namely, an antibody to vesicular acetylcholine transporter (VAChT), to immunolabel cholinergic axons and cell bodies in specimens of urinary bladder, seminal vesicle, vas deferens, and prostate gland obtained from neonates and children post mortem. In addition some sections were double-immunolabeled with VAChT and either neuropeptide Y (NPY) or nitric oxide synthase (NOS). The results demonstrated a rich cholinergic innervation to the muscle coat of the bladder body with a much less prominent, but nonetheless significant, cholinergic innervation to the smooth muscle components of the seminal vesicle, vas deferens, and prostate. Small ganglia were scattered throughout the detrusor muscle of the urinary bladder, approximately 75% of the intramural neurons being VAChT immunoreactive, whereas approximately 95% contained NPY and approximately 40% contained NOS. VAChT immunoreactivity was observed in 40% of neurons in ganglia scattered throughout the pelvic plexus. Almost all these cholinergic neurons contained NPY and approximately 65% contained NOS. Almost all the cholinergic nerve fibers throughout the genitourinary organs also contained NPY. Although NOS was sparse in the cholinergic nerves of the bladder body, it occurred in the majority of cholinergic nerves at the bladder neck and was also present in a proportion of the cholinergic nerves in the other organs examined. VAChT-immunoreactive nerves were also observed in a sub-epithelial location in all the organs examined, the majority containing NPY, whereas a small proportion contained NOS. Although doubt remains about the function of sub-epithelial cholinergic nerves in the urinary bladder, the majority of similar nerves in the seminal vesicle, vas deferens, and prostate gland are considered to be secretomotor. Collectively these findings demonstrate that the cholinergic innervation of the male genitourinary system is well established in the neonate and child. Neurourol. Urodynam. 19:185-194, 2000.

Comparative localization of heme oxygenase-2 and nitric oxide synthase in the autonomic innervation to the human ductus deferens and seminal vesicle

PURPOSE

The aim of present study was to determine the topographic relationship between heme oxygenase-2 (HO-2), which synthesizes carbon monoxide (CO), and neuronal nitric oxide synthase (nNOS), which generates nitric oxide (NO), in the autonomic nerves of the human ductus deferens and seminal vesicle.

MATERIALS AND METHODS

Specimens of the ductus deferens and seminal vesicle were obtained during cancer surgery or vasectomy. HO-2 and nNOS were localized by indirect immunofluorescence. Additionally, the histochemical NADPH-diaphorase (NADPH-d) activity of NOS was demonstrated using a standard staining method and some modifications.

RESULTS

Anti-HO-2 labeling stained virtually all nerve cell bodies in local ganglia of the pelvic plexus, which is composed of a mixed population of postganglionic sympathetic and parasympathetic neurons supplying the pelvic viscera. Furthermore, nerve cell bodies in the wall of the seminal vesicle, which are considered an extension of the pelvic plexus, were also found to stain positively for HO-2. Some of the HO-2-immunoreactive ganglion cells were also nNOS-positive, their proportion varying between individual ganglia but generally not exceeding 20%. Both enzymes were present in large adventitial nerve trunks. Only nNOS but no HO-2 was found in small intramuscular and mucosal nerve fibers. In both the ductus deferens and seminal vesicle, the highest density of nNOS-containing nerve fibers was in the lamina propria of the mucosa. A well-developed plexus of nNOS-positive nerve fibers was also observed in the muscular layer of the seminal vesicle. By contrast, there was a very sparse innervation by nNOS-positive nerve fibers in the muscle coat of the ductus deferens. In addition, a population of epithelial cells in the seminal vesicle may contain an isoform of NOS, as revealed by a resistant NADPH-d activity.

CONCLUSIONS

These findings set the scene for functional studies which will hopefully clarify the biological role of CO and NO in the control of the ductus deferens and seminal vesicle.

Expression of bone morphogenetic protein 7 in murine epididymis is developmentally regulated

Bone morphogenetic proteins (BMPs) have been shown to play a role in the functional maintenance of the adult epididymis. To begin to investigate the role of BMP signal transduction during postnatal epididymal development, we examined the expression profile of Bmp7 in murine epididymis by in situ hybridization. Our data show that during early postnatal development (younger than 3 wk of age), Bmp7 transcripts are detected uniformly in epithelial cells throughout the epididymis. As the mice aged (from 3 to 4 wk), Bmp7 expression was gradually restricted to the initial segment, with increased levels. Bmp7 expression in the rest of the caput and corpus regions became undetectable after 4 wk of age. However, after 4 wk of age, an ascending gradient of Bmp7 expression was observed in the epididymal epithelial cells in the transition from the cauda epididymal tubule to the vas deferens. Such a unique expression profile of Bmp7 strongly suggests that epididymis-produced BMP7 may play a role in the development and functional maintenance of the epididymis, and that Bmp7 expression in the epididymis is developmentally regulated.

Cyclic enkephalin analogs that are hybrids of DPDPE-related peptides and metenkephalin-Arg-Gly-Leu: prohormone analogs that retain good potency and selectivity for delta opioid receptors

We report here on the binding affinity and bioassay results of cyclic enkephalin analogs comprising a cyclic moiety and C-terminal fragment of MERGL, where ME denotes methionine enkephalin. MERGL (YGGFMRGL) has been suggested to be cleaved enzymatically by membrane-bound enkephalinase 24.11 to leave ME and the tripeptide RGL. In our study we have synthesized hybrids of DPDPE or DPLCE and the C-terminal tripeptide RGL in order to mimic a prohormone able to cross the blood-brain barrier. The study has shown that of the homologs presented here, analogs of DPLCE often are more potent at delta opioid receptors both in binding affinity and in bioactivity at the MVD, than DPDPE. Our hypothesis that hybrids (consisting of the drug and the spacer for the carrier) could be designed which would either have no opioid activity or, alternatively, be by themselves very active, has been verified.

Cyclic AMP regulates expression of the gene coding for a mouse vas deferens protein related to the aldo-keto reductase superfamily in human and murine adrenocortical cells

Mouse vas deferens protein (MVDP) is a member of the aldo-keto reductase superfamily. The regulation of MVDP gene expression by activators of the protein kinase A signalling pathway was investigated in human (H295-R) and murine (Y1) adrenocortical carcinoma cells. Immunoblotting with polyclonal antibodies showed that MVDP is expressed in adrenal glands from mouse, rat, rabbit and guinea-pig, probably under the control of ACTH. In both adrenocortical cell lines used, MVDP is constitutively synthesized and its accumulation is increased by treatment with cAMP or forskolin. MVDP mRNA steady-state levels were up-regulated by forskolin in adrenocortical cells by a process that does not require de novo protein synthesis. The results suggest that cAMP is at least one of the key regulators of adrenal MVDP expression and that this effect is direct.

Mechanical alterations in smooth muscle from mice lacking desmin

Mice with a null mutation introduced in the desmin gene were used to study the mechanical role of intermediate filaments in smooth muscle cells. Vas deferens (VD), urinary bladder (UB) and portal vein (PV) preparations were obtained from adult animals lacking desmin (Des -/-) and from age- and weight-matched wild-type animals (Des +/+). Active force per cross-sectional area was decreased in the smooth muscle of the Des -/- compared with Des +/+ mice (VD to 42%; UB to 34%). Quantitative gel electrophoresis suggests a marginally lower cellular content of myosin, but the organization of the contractile apparatus appeared unchanged by electron microscopy. A similar reduction in stress was measured in Des -/- skinned fibres showing that altered activation mechanisms were not involved. The results indicate that the reduced active force is caused by low intrinsic force generation of the contractile filaments or subtle modifications in the coupling between the contractile elements and the cytoskeleton. The relationship between length and passive stress was less steep in the Des -/- samples and a second length force curve after maximal extension revealed a loss of passive stress. The maximal shortening velocity was reduced in Des -/- skinned VD and UB preparations by approximately 25-40%. This was associated with an increased relative content of the basic essential myosin light chain, suggesting that alterations in the contractile system towards a slower, more economical muscle had occurred. PV preparations showed no difference in mechanical properties in Des +/+ and Des -/- animals, a result that was consistent with the predominance of vimentin instead of desmin in this vascular tissue. In conclusion, the results show that, although intermediate filaments in smooth muscle are not required for force generation or maintenance of passive tension, they have a role in cellular transmission of both active and passive force.

Computer-assisted visualization of the rat epididymis: a methodological study based on paraffin sections autometallographically stained for zinc ions

A concept for the computer-assisted visualization of tubular organs is presented. Unmarked histological zinc-stained serial sections from the epididymis of the Wistar rat were aligned to demonstrate the concept. Virtual images were made through the aligned sections and served as controls for the alignment process. Animation of the serial sections and the virtual images revealed new information about the structure of the organ under investigation. The analysis was used to upgrade the anatomical knowledge of rat epididymis by describing how the epididymal duct runs through the structure. The proximal parts of the epididymis contain large communicating septa of connective tissue dividing the caput and the upper part of the corpus epididymidis into segments. The tortuousness was high in the caput with many turns within a small area of the epididymis, whereas longer loops were found in the lower part of the corpus and cauda epididymidis. The tube of the vas deferens was found to become an integrated part of the ductal system in the cauda epididymidis, although it was histologically easy to distinguish from the epididymal duct. The total number of cross-sections of the ductus epididymidis in the 2254, 15-microm-thick, tissue sections analysed was 104700, giving a minimum length of the ductal system of 1.5 m.

Regulation of androgen and estrogen receptors in male excurrent ducts of the goat: an immunohistochemical study

BACKGROUND

Since androgens and/or estrogens must bind with specific receptors in order to elicit a response at the target organ(s), it is important to understand factors that regulate expression of androgen receptors (AR) and estrogen receptors (ER). Hence, the objective of the study is to determine the relative significance between circulating androgen (CA) and luminal androgen (LA) in maintaining normal expression of AR and ER in male excurrent ducts.

METHODS

Mature Nubian goats were subjected for 15 days each to the following treatments: (1) bilateral orchidectomy, (2) bilateral orchidectomy and testosterone treatment, (3) unilateral ligation of the extratesticular rete, and (4) unilateral orchidectomy. Tissues from different segments of the excurrent ducts were fixed in 4% paraformaldehyde and embedded in Paraplast-plus. Antigenic sites for AR and ER were immunolocalized using PG-21 rabbit antirat/human antibody and H-222 rat antihuman monoclonal antibody, respectively. The avidin-biotin horseradish peroxidase procedure was used to identify positive immunoreactivity. Negative controls included incubation of sections with irrelevant IgG in place of primary antibody.

RESULTS

In intact animals, whereas AR were found in epithelial, connective tissue, and peritubular smooth muscle cells of the efferent ductules, regions I-V of the epididymis, and ductus deferens, ER were confined to nonciliated cells of the efferent ductules. Bilateral orchidectomy caused a severe loss of both AR and ER staining. Testosterone replacement to orchidectomized animals restored staining of both AR and ER to the intact level. Neither unilateral ligation of the extratesticular rete nor unilateral orchidectomy had any effect on AR or ER immunostaining.

CONCLUSION

Circulating androgen alone, without any input from luminal androgen or other rete fluid contents, can regulate expression of both androgen receptor and estrogen receptor.

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.

Higher proportion of intact exon 9 CFTR mRNA in nasal epithelium compared with vas deferens

The 5-thymidine (5T) variant of the cystic fibrosis transmembrane conductance regulator (CFTR) intron 8 polypyrimidine tract (IVS8-T tract) is the most frequent CFTR gene alteration identified in men with congenital bilateral absence of vas deferens (CBAVD). This alternative splicing variant gives rise to two transcripts, one normal with exon 9 intact and the other with in-frame deletion of exon 9. That CBAVD men usually have none of the other clinical signs of classical cystic fibrosis (CF) suggests less functional CFTR is produced in the reproductive tract than in other CF-associated organs. Nasal epithelia and segments of vas deferens were obtained from healthy, previously vasectomized men who presented for vasectomy reversal. Quantitative RT-PCR was performed on these specimens, with the region of CFTR cDNA spanning exon 9 amplified. For both nasal and vasal tissues, a strong positive correlation was found between the length of the IVS8-T tract and the proportion of mRNA with exon 9 intact. In addition, within the same subject, a significantly higher level of transcripts lacking exon 9 was found in vas deferens than nasal epithelia, regardless of the IVS8-T genotype. These findings suggest that the splicing of CFTR precursor mRNA is less efficient in vasal epithelia compared with respiratory epithelia. Thus, differential splicing efficiency between the various tissues which express CFTR provides one possible explanation for the reproductive tract abnormalities observed in infertile men with CFTR gene alterations but without other clinical manifestations of CF.

Immunolocalization of androgen receptor and estrogen receptor in the developing testis and excurrent ducts of goats

BACKGROUND

Because of the significance of androgens and estrogens in prenatal and postanatal differentiation of the testis and excurrent ducts, it is important to understand the developmental pattern of androgen receptor (AR) and estrogen receptor (ER) in these organs.

METHODS

Tissues from 1-23-week-old goats were fixed in 4% paraformaldehyde and embedded in Paraplast-plus. Antigenic sites for AR and ER were immunolocalized using the PG-21 rabbit anti-rat/human antibody and the H-222 rat anti-human monoclonal antibody, respectively. The avidin-biotin horseradish peroxidase procedure was used to identify positive immunoreactivity. Controls included incubation of sections with irrelevant IgG in place of primary antibody.

RESULTS

Within the testis, immunostaining for AR in the nuclei of Sertoli cells increased gradually from mild at week 1 to strong at week > or = 19. In contrast, nuclei of peritubular myoid cells and Leydig cells exhibited moderate to strong reaction for AR in all animals. Germ cells were negative. Within the rete testis, efferent ductules, regions I-V of the epididymis, and ductus deferens, nuclei of all epithelial cells, peritubular myoid cells, and intertubular connective tissue cells expressed moderate to strong staining for AR at all ages. ER were confined to nonciliated cells of the efferent ductules, which displayed moderate staining in all animals, beginning from week 1.

CONCLUSIONS

Nuclear AR staining, found in all testicular cells (except germ cells) and excurrent duct cells examined, was observed to change in an age-related manner only in Sertoli cells, where staining intensity increased between week 1 and week 19. Staining for ER, confined to nonciliated epithelial cells of the efferent ductules, was not affected by postnatal age.

[Species-differences in diabetes-induced alterations in vasa deferentia endothelin receptors]

PURPOSE

As there is increasing evidence that diabetes induces changes in the plasma levels of endothelins (ETs) and the properties of the ET receptors in peripheral tissues and there are reports indicating the presence of significant amounts of endothelin binding sites in the mammalian vasa deferentia, we studied possible alterations in ET receptor characteristics in the vasa deferentia of rats and rabbits.

METHODS

Diabetes was induced with i.v. injections of streptozotocin (65 mg/kg) and alloxan (100 mg/kg) in rats and rabbits, respectively. We investigated the binding characteristics of endothelin (ET) receptors in the vasa deferentia of four and five month experimentally-induced diabetic rats and rabbits, respectively. The densities and pharmacological properties of ET receptors in the rat and rabbit vasa deferentia were examined by radioligand receptor binding studies using [125I]ET-1.

RESULTS & CONCLUSION

Receptor binding experiments with [125I]ET-1 revealed a dramatic upregulation in the expression of a single class of specific, saturable, high affinity of [125I]ET-1 binding sites in the diabetic rats but not in the vasa deferentia of diabetic rabbits. ET-1 (non-selective), ET-3 (ETC selective), BQ 610 (ETA selective) and IRL 1620 (ETB selective) compounds inhibited [125I]ET-binding to the rats and rabbits vasa deferentia consistent with the predominance of ETA receptors in these tissues.

Detection of glycoconjugates in the ductus epididymis of the prepubertal and adult horse by lectin histochemistry

This paper describes an approach for studying the structure of glycoconjugates found in the principal cells lining the epididymal duct in adult and prepubertal horses, using ten different lectin horseradish conjugates: Con-A, LCA, WGA, GSA-II, SBA, PNA, RCA-I, DBA, UEA-I, and LTA. Saponification and sialidase procedures, followed by lectin binding, were employed to visualize the distribution and to reveal the sequence of sialoglycoconjugates in ductus epididymis. In the adult horse the results demonstrated variations in the content and distribution of glycosidic residues of glycoconjugates in different epididymal regions (caput, corpus, cauda) and vas deferens, suggesting that each epididymal segment has a specific function. In particular, staining of the Golgi-zone in the principal cells lining corpus epididymis was interpreted as evidence for synthesis and secretion of glycoconjugates and sialoglycoconjugates. In the prepubertal horse, only the glycocalyx of the epithelial cells lining the epididymal duct showed reactivity toward the different lectins used, suggesting hormonal regulation of the epididymis activity. Additional, the heterogeneity of the lectin staining pattern of the adult horse epididymis reported in this investigation also suggests the existence of different functional segments along the epididymal duct.

Oxytocin and oxytocin receptor expression in reproductive tissues of the male marmoset monkey

Using a combination of reverse transcriptase polymerase chain reaction to detect specific mRNA and immunohistochemistry employing antibodies that recognize two different epitopes for each molecule, the local production of oxytocin (OT) and its cognate receptor was investigated in the male marmoset monkey (Callithrix jacchus). There was synthesis of both OT and the oxytocin receptor (OTR) within the testis, and both were markedly expressed within the Leydig cells. A weak staining for both OT and its associated neurophysin could also be detected in Sertoli cells in some animals. Expression of OT or neurophysin does not appear to be significant in the epididymis, though there appears to be synthesis of the receptor in some peritubular muscle cells of the epididymis and in the vas deferens. Within the prostate, there appears to be no production of OT or neurophysin, though there appears to be weak expression of the OTR in the basal layers of the secretory epithelium. Similarly in the bulbourethral gland, only OTR immunoreactivity could be detected. Receptors appear to be present in the myoid cells encompassing the glandular lobules and are presumably able to respond to systemic OT. An analysis of juvenile marmosets indicates that the testicular OT system appears to become established during puberty. Thus, in this New World monkey the testis is able to support a local OT-based paracrine-type system, though the prostate and bulbourethral gland are probably only able to respond to exogenous OT.

Immunolocalization of receptors for androgen and estrogen in male caprine reproductive tissues: unique distribution of estrogen receptors in efferent ductule epithelium

Androgens and estrogens affect physiological processes in the testis and male excurrent duct system. This study was designed to identify and characterize distribution of androgen receptors (AR) and estrogen receptors (ER) in the reproductive organs of the male goat. Tissues, including testis, efferent ductules, epididymis (regions I-V), and ductus deferens, were obtained from five mature Nubian goats, fixed in 4% paraformaldehyde, and embedded in paraplast. Antigenic sites for AR were unmasked by microwave treatment (four times, 5 min each) of tissue sections immersed in 10 mM citrate (pH 6) and were detected using the PG-21 rabbit anti-rat/human antibody. Antigenic sites for ER were identified using the H-222 rat anti-human monoclonal antibody after tissue sections were treated with pronase (0.5 mg/ml, 37 degrees C, 8 min). Avidin-biotin horseradish peroxidase procedures were used to identify positive immunoreactivity. Irrelevant IgG was substituted for primary antibody in negative controls. Positive nuclear immunostaining for AR was observed in all types of epithelial cells, peritubular smooth muscle cells, and intertubular fibroblasts of the intratesticular rete, efferent ductules, epididymis (regions I-V), and ductus deferens, as well as in Sertoli, Leydig, and peritubular myoid cells and intertubular fibroblasts of the testis. In contrast, nuclear immunostaining for ER was confined to nonciliated cells of the efferent ductules. Thus, AR-positive cells are ubiquitously distributed in caprine testicular and excurrent ductular tissues, and ER-positive cells are unique to the efferent ductules. The caprine model should be useful in studies designed to determine mechanisms through which androgens and estrogens regulate development and function of the testes and excurrent ducts.

Light and electron microscopic immunohistochemical localization of protein gene product 9.5 and ubiquitin immunoreactivities in the human epididymis and vas deferens

The distribution of protein gene product 9.5 (PGP) and ubiquitin immunoreactivities in the ductuli efferentes, ductus epididymidis, and ductus deferens of humans was studied by Western blot analyses and light and electron microscopic immunocytochemistry. PGP immunoreactivity was intense in the ductuli efferentes and weak in the ductus epididymidis and ductus deferens, while ubiquitin immunoreactivity was intense in the ductuli efferentes and ductus epididymidis and very weak in the ductus deferens. In the ductuli efferentes epithelium, PGP immunolabeling was observed in the cytoplasm of principal cells, whereas ubiquitin immunoreactivity was found in the nucleus and cytoplasm of principal cells and ciliated cells. In the ductus epididymidis epithelium, only scattered cells (mitochondria-rich cells) showed PGP immunoreaction in their cytoplasm, whereas ubiquitin immunostaining was detected in the nucleus and cytoplasm of most epithelial cells, except for the cauda, where ubiquitin immunolabeling was observed only in the nuclei. The ductus deferens showed no immunostaining for PGP, and only nuclear immunoreactivity to ubiquitin. The ultrastructural localization of PGP immunoreactivity was in the apical cytosol and microvilli. In addition to these locations, ubiquitin immunoreactivity was also found in the nucleus of all cell types and cilia of ciliated cells. Although the distribution of PGP and ubiquitin immunoreactivities in humans differs from that reported in rats, it seems that PGP and ubiquitinated proteins are secreted into the epididymal lumen in both species.

Cytoskeletal differences between stereocilia of the human sperm passageway and microvilli/stereocilia in other locations

BACKGROUND

Stereocilia of the human ductus epididymidis and ductus deferens display unique features in that they arise from an apical cell protrusion (hillock) and contain thick stem portions which are interconnected by cytoplasmic bridges. The molecular basis for this unique fusion and branching pattern is hitherto unknown. These morphologic specialties led us to study the cytoskeleton of male spermway stereocilia with respect to the major proteins that constitute the supportive cytoskeleton of intestinal microvilli and inner ear stereocilia.

METHODS

Samples of the human epididymidis and ductus deferens were studied by immunoblotting and immunocytochemistry at the light and electron microscope levels.

RESULTS

Spermway stereocilia are supported by an internal actin filament bundle crosslinked by fimbrin and associated with the membrane linker molecule ezrin. The stem portions and hillock area are supplied with the crossbridge forming molecule alpha-actinin. Spermway stereocilia differ from brush border microvilli of the intestine, kidney, and ductuli efferentes by the lack of the second bundling protein villin and the unusual expression of alpha-actinin in the stem region. They resemble inner ear stereocilia by the presence of fimbrin and absence of villin, but differ from them by expression of ezrin and alpha-actinin. Thus, the main molecular difference between spermway stereocilia and stereocilia/microvilli of other locations is the presence of alpha-actinin in their stem portion and the hillock area.

CONCLUSIONS

Since alpha-actinin can form crossbridges between adjacent actin filaments (bundles) at longer distances than the other crosslinker of the stereocilium core bundle, fimbrin, we assume that alpha-actinin is essential for both the formation of the stem portions of spermway stereocilia and for the generation of their striking branching pattern. A developmentally regulated temporal sequence of expression of fimbrin and alpha-actinin might control the unique architecture of spermway stereocilia.

Surgical opportunities to explore the function of the human epididymis

The animal epididymis was known to play an essential role in the acquisition of motility and fertilising capacity of testicular spermatozoa. Little was known about the function of the human epididymis and this paper describes studies arising from tissues obtained at the time of surgical procedures on the epididymis and vas deferens. Even though the human epididymis differs from that of other animals in fine structure and luminal contents, its function is similar in that spermatozoa gain motility and fertilising capacity during their passage through it. The poor fertilising capacity (24% of 76 cycles) and 2 (2.6%) conceptions with spermatozoa from an obstructed epididymis or vas deferens compared with a fertilisation rate of 88% (pregnancy in 37.5%) in men without obstruction is evidence of this. The defect in fertilising capacity may be overcome by using the technique of intracytoplasmic sperm injection, where fertilisation and embryo transfer occurred in 95% of the 38 couples with obstruction and 34% of the wives conceived.

Mouse androgen-dependent epididymal glycoprotein CRISP-1 (DE/AEG): isolation, biochemical characterization, and expression in recombinant form

In the rat, the secretory glycoprotein DE/AEG is one of the main constituents of the epididymal fluid. We have recently reported the cloning of the cDNA for the related cysteine-rich secretory protein-1 (CRISP-1) from murine epididymis (Haendler et al., 1993; Endocrinology 133:192-198). The protein has now been isolated from the same organ and its N-terminal amino acid sequence has been determined. CRISP-1 exhibited an isoelectric point of approximately 6.8. High levels of CRISP-1 antigen were detected in the corpus and cauda of the epididymis, vas deferens, seminal vesicle, prostate, and in the salivary gland by immunohistochemistry. A quantitative analysis of the cauda epididymal fluid by sandwich ELISA revealed that CRISP-1 represented approximately 15% of the total protein. For heterologous expression, the CRISP-1 coding sequence was introduced into the pMPSV/CMV vector before transfection of baby hamster kidney (BHK) cells and selection with puromycin and neomycin. Expression in insect cells was achieved by co-transfection of Sf9 cells with a transfer vector and baculovirus DNA. Recombinant CRISP-1 was isolated in quantities sufficient for structural analysis. Ethyl maleimide treatment showed that all 16 cysteines were engaged in disulfide bonds. Proteolytic digestion demonstrated that the six cysteines localized in the N-terminal moiety formed three bonds with each other, suggesting the existence of two discrete domains in the protein.