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1.
The anterior testicular ducts of squamates transport sperm from the seminiferous tubules to the ductus deferens. These ducts consist of the rete testis, ductuli efferentes, and ductus epididymis. Many histological and a few ultrastructural studies of the squamate reproductive tract exist, but none concern the Hydrophiidae, the sea snakes and sea kraits. In this study, we describe the anterior testicular ducts of six species of hydrophiid snakes as well as representatives from the Elapidae, Homolapsidae, Leptotyphlopidae, and Uropeltidae. In addition, we examine the ultrastructure of these ducts in the yellow‐bellied Sea Snake, Pelamis platurus, only the third such study on snakes. The anterior testicular ducts are similar in histology in all species examined. The rete testis is simple squamous or cuboidal epithelium and transports sperm from the seminiferous tubules to the ductuli efferentes in the extratesticular epididymal sheath. The ductuli efferentes are branched, convoluted tubules composed of simple cuboidal, ciliated epithelium, and many species possess periodic acid‐Schiff+ granules in the cytoplasm. The ductus epididymis at the light microscopy level appears composed of pseudostratified columnar epithelium. At the ultrastructural level, the rete testis and ductuli efferentes of P. platurus possess numerous small coated vesicles and lack secretory vacuoles. Apocrine blebs in the ductuli efferentes, however, indicate secretory activity, possibly by a constitutive pathway. Ultrastructure reveals three types of cells in the ductus epididymis of P. platurus: columnar principal cells, squamous basal cells, and mitochondria‐rich apical cells. This is the first report of apical cells in a snake. In addition, occasional principal cells possess a single cilium, which has not been reported in reptiles previously but is known in some birds. Finally, the ductus epididymis of P. platurus differs from other snakes that have been studied in possession of apical, biphasic secretory vacuoles. All of the proximal ducts are characterized by widening of adjacent plasma membranes into wide intercellular spaces, especially between the principal cells of the ductus epididymis. Our results contribute to a larger, collaborative study of the evolution of the squamate reproductive tract and to the potential for utilizing cellular characters in future phylogenetic inferences. J. Morphol. 2012. © 2011 Wiley Periodicals, Inc.  相似文献   

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3.
The microanatomy of the testes and testicular ducts (rete testis, ductuli efferentes, ductus epididymis and ductus deferens) of Leiolepis ocellata (Agamidae) was investigated using light microscopy including histochemistry. Each testis contains seminiferous tubules and interstitial tissues. The former house spermatogenic cells (spermatogonia A & B, preleptotene, primary and secondary spermatocytes, spermatids (steps 1–8) and spermatozoa) and Sertoli cells, while the latter comprise peritubular and intersitial tissues. The rete testis is an anastomosing duct, having intratesticular and extratesticular portions. The proximal region of ductuli efferentes has wider outer ductal and luminal diameters than those of the distal region. The convoluted ductus epididymis is subdivided into four regions (initial segment, caput, corpus and cauda), based on the ductal diameter, epithelium characteristics and cell components. The ductus deferens has the greatest diameter and is divided into the ductal and ampulla ductus deferens. The ductal portion is subdivided into the proximal and distal regions, based on the epithelium types and ductal diameters. The ampulla ductus deferens is a fibromuscular tube, having numerous mucosal folds projecting into the lumen. Spermiophagy is detectable in the ductus epididymis and ductus deferens. The present results contribute to improved fundamental knowledge on the microanatomy of the reptilian reproductive system.  相似文献   

4.
Inhibin was localized in the ovine testis, excurrent ducts, and accessory sex glands by using a rabbit antiserum against a synthetic polypeptide representing the first 30 amino acids of porcine inhibin alpha-subunit. Concentrations of inhibin in fluids entering and leaving the epididymis also were determined in a radioimmunoassay using the same antibody. In the testis, immunostaining of inhibin was conspicuous in the seminiferous epithelium. Leydig cells occasionally were stained and the tunica media of blood vessels always was stained. Intense staining was observed in the epithelia lining the rete testis and ductuli efferentes. Staining also was intense in the epithelium of the initial segment and proximal caput epididymidis, and became less intense along the length of the epididymis. These observations were consistent with concentrations of inhibin in rete testis fluid (8.2 pmol/ml) entering the ductuli efferentes and in cauda epididymal plasma (0.67 pmol/ml) leaving the epididymis. Epithelia of ampullary and vesicular glands and of some prostatic acini were positively stained, but bulbourethral glands were never stained. Adrenal cortex, some proximal convoluted tubules in the kidney, and transitional epithelium of the urethra also were stained. Based on radioimmunoassay data and fluid flow rates for the ram, it was concluded that almost all of the 328 pmol inhibin that enters the ductuli efferentes daily is endocytosed in the proximal parts of the excurrent duct system. The physiological role(s) for inhibin, or inhibin-like peptides, in the excurrent duct system remains speculative.  相似文献   

5.
Synopsis The genital ducts ofHeterodontus portusjacksoni consist of the sperm carrying ducts (the rete testis, ductuli efferentes, and initial and terminal segments of the ductus epididymidis) and the Leydig glands (anterior opisthonephros). The ducts are lined by a ciliated epithelium which maintains a barrier to the transport of solute between blood and the lumen of the duct. Spermatozoa, Sertoli cell bodies, Sertoli cell cytoplasts and cellular debris are released from spermatocysts into the longitudinal canal of the rete testis. However, only the Sertoli cell cytoplasts persist throughout the sperm ducts. The epithelia lining the initial segment of the ductus epididymidis and secretory tubules of the Leydig glands are specialized for protein secretion and (particularly the Leydig glands) must be the main source of luminal protein in the ductus epididymidis. The epithelium lining the terminal segment of the ductus epididymidis also secretes protein, reabsorbs fluid and sodium, and may carry out heterophagic digestion. Spermatozoa develop the capacity for motility in the extratesticular sperm ducts, but do not undergo structural changes. However, they form spherical bundles in the terminal segment of the ductus epididymidis. It is suggested that the reduction in ratio of sodium:potassium from 48:8 in the ductuli efferentes to 3:4 in the distal end of the terminal segment of the ductus epididymidis may favour sperm survival.  相似文献   

6.
The ductuli efferentes and rete testis of the guinea pig were isolated by micro dissection, fixed in cold buffered osmium tetroxide, and sectioned for examination with the light and electron microscopes. Proximal and distal segments of the ductuli efferentes were identified and their respective cytological organizations characterized. The cytological components of the rete testis are briefly described and figured. Non-ciliated and ciliated cells are found in both segments of the ductuli efferentes. The non-ciliated cells have a microvillous border, mitochondria, a Golgi complex, an ubiquitous endoplasmic reticulum, and numerous cytoplasmic vacuoles. The ciliated cells contain more mitochondria, an endoplasmic reticulum with a relatively sparse distribution, and few, if any, cytoplasmic vacuoles. A regional difference exists in proximal and distal segments based on the distribution, size, number, and electron opacity of the cytoplasmic vacuoles. Attention was paid to the disposition of the endoplasmic reticulum and its relation to the system of cytoplasmic vacuoles. These findings are interpreted as suggesting that the continuity of the vacuolar system with elements of the endoplasmic reticulum represents a pathway for transfer of large quantities of fluid, an activity which has long been ascribed to the epithelium of the ductuli efferentes. Periductular capillaries possess pore-like apertures in their endothelia similar to those in other tissues known to engage in fluid transfer.  相似文献   

7.
Histopathology in testes from mice with actively induced experimental orchitis (EAO) (active EAO) and those from recipients of testis-sensitized lymphocytes (passive EAO) had different distributions. In passive EAO, maximum orchitis existed in the straight tubules, rete testis, and ductus efferentes, obstruction of which led to extreme dilatation of seminiferous tubules. Unusual intralymphatic granulomata also resulted in dilated testicular lymphatics. In active EAO, maximum orchitis affected seminiferous tubules under the testicular capsule, away from the rete testes. Vasitis was common and occurred in both active and passive EAO. In normal testes, IA+ F4/80+ cells were sparse but formed a cuff around the straight tubules. After immunization with testis in adjuvant or with adjuvant alone, the number, size, and staining intensity of IA+ cells increased dramatically beginning on day 5, 7 days before disease onset. Simultaneously, epithelial cells confined to the ductus efferentes became Ia+. Although recipients of sensitized lymphocytes also developed epithelial Ia in the ductus efferentes, they did not show changes in testicular interstitial Ia+ cells. Our findings indicate that testicular autoantigens are not completely sequestered, but are accessible to and can react with passively transferred immune lymphocytes in well-defined regions of the germ cell compartment. These regions coincided to a large extent with maximum expression of periductal or epithelial Ia. Changes in Ia+ cells in the testis, which are inducible by adjuvants and precede orchitis, may account in part for the different distribution of histopathology of active EAO.  相似文献   

8.
T A Aire 《Acta anatomica》1979,103(3):305-312
The epididymal region of the Japanese quail was studied histologically. The organ consists of the extratesticular portion of the rete testis, the ductuli efferentes proximales and distales, the ducti conjugentes and ductus epididymidis. Distinct tubuli recti link the seminiferous tubules with the rete testis. The non-ciliated cells of the ductuli efferentes proximales and distales show, between them, certain internal structural differences which were highlighted. In 40% of the birds, the ductus deferens showed dark-grey pigments, regarded as melanin. The epididymal region was generally similar in structure to that of the domestic fowl, turkey and duck.  相似文献   

9.
Efferent reproductive ducts of male mice, including ductuli efferentes, epididymis, and vas deferens, were fixed and embedded in paraffin, and sections were stained with a battery of lectin-horseradish peroxidase conjugates to localize specific sugars or sugar sequences in glycoconjugates. Cilia and the apical surfaces of ciliated cells in the ductuli efferentes stained intensely with lectin specific for sialic acid and terminal alpha-N-acetyl-D-galactosamine. Flask cells and clear cells in the epididymis reacted positively and similarly with most lectins used, providing evidence that these cell types are related. In contrast, disparities in lectin staining suggest that flask cells and clear cells are a cell type distinct from principal cells. Basal cells were not present in the ductuli efferentes but formed a continuous layer in the epididymis and vas deferens. Basal cells contained oligosaccharides terminated by sialic acid and alpha-D-galactose and varying amounts of terminal beta-D-galactose and alpha-N-acetyl-D-galactosamine. Basal cells also stained variably with lectins specific for the core region of complex type N-glycosidic side chains. The basal cells varied structurally, having long spinous apical processes approaching or reaching the lumen in region I of the epididymis and being low cuboidal or squamoid and lacking apical processes in epididymal regions II-V and in the vas deferens. The contiguous nature of the basal cells and the presence of glycoconjugates bearing terminal alpha-galactosyl residues in all basal cells suggest a possible role for these cells in a regulatory influence on transepithelial movement of fluid and/or ions in the epididymis and vas deferens.  相似文献   

10.
Several glycoconjugates are thought to bind spermatozoa as they pass through reproductive ducts. Paraffin sections of testis, ductuli efferentes, epididymis, and vas deferens of male mice were stained with ten different lectin-horseradish peroxidase conjugates to localize possible sites of synthesis and secretion of such glycoconjugates, based on the carbohydrate moieties in their constituent oligosaccharide side chains. Principal (columnar) cells lining the efferent ducts, germinal epithelium, and developing and maturing spermatozoa were examined with light microscopy. Staining of the Golgi and apical zones of cells was interpreted as evidence for synthesis and secretion of glycoconjugates. Principal cells synthesized and secreted glycoconjugates with sugar moieties as follows: sialic acid, all regions of the efferent ducts examined; the terminal disaccharide D-galactose- (beta 1----3) -N-acetyl-D-galactosamine, all regions of ducts except epididymis I; terminal alpha-D-galactosamine, some cells in epididymis III-V; N-acetyl-D-galactosamine, ductuli efferentes, epididymis I, II, and some cells in epididymis III-V; alpha-L-fucose, ductuli efferentes, vas deferens, and all regions of the epididymis except IV; N-glycosidic side chains, ductuli efferentes, vas deferens, and epididymis I, IV, and V. All of these sugar residues as well as N-acetyl-D-glucosamine were associated with the acrosomes and tails of spermatozoa throughout the ducts except for alpha-N-acetyl-D-galactosamine in epididymis I, and all occurred during one or more stages of spermiogenesis. The synthesis and secretion of glycoconjugates that bind to spermatozoa appear to involve more regions of the primary reproductive structures than was believed previously.  相似文献   

11.
The fine structure of the epithelium lining the extratesticular rete testis, ductuli efferentes and ductus epididymidis of the rabbit has been investigated. In the ductuli efferentes the epithelium is composed of two cell types, principal cells and ciliated cells. The latter type is distinguished from principal cells by the presence of cilia projecting into the lumen and the position of the nucleus in the apical half of the cell. Principal cells in this segment are characterized by micropinocytotic vesicles on the surface plasma membrane and a variety of small dense bodies scattered throughout the cytoplasm. In the ductus epididymidis basal cells replace ciliated cells as the second cell type, but differences between various segments of the epididymis are related to the fine structure of the principal cells. In the proximal caput epididymidis (Nicander's region 1) the principal cells are tall with long microvilli. They typically contain a small Golgi apparatus and a cluster of dense bodies adjacent to the nucleus. In the distal caput epididymidis (Nicander's regions 2-5) the apical cytoplasm of principal cells is filled with numerous micropinocytotic vesicles and large multivesicular bodies; these features are interpreted as signs of absorptive activity. The multivesicular bodies are absent from the cytoplasm of principal cells in the corpus epididymidis (Nicander's region 6) and, instead, numerous elements of smooth endoplasmic reticulum, a large Golgi apparatus, lipid droplets and dense bodies characterize principal cells in this segment. Towards the proximal cauda epididymidis (Nicander's region 7), the number of dense bodies (lysosomes) in the cytoplasm increases considerably. In the globose cauda (Nicander's region 8), the principal cells are reduced in height, and in addition to the features described in region 7, are characterized by a concentric array of rough endoplasmic reticulum in the basal cytoplasm. These observations are discussed in relation to the role of the epididymis in promoting the maturation and survival of spermatozoa.  相似文献   

12.
Whole-mounted preparations of the tunica albuginea of the rat testis were studied using light microscopy techniques for demonstration of cholinergic nerve fibres (Karnovski-Root method), catecholaminergic nerve fibres (De la Torre's method) and actin filaments (avidin-biotin-peroxidase method). An ultrastructural study of different regions of the albuginea was also performed. Cholinergic fibres were seen to penetrate into the albuginea with the testicular artery to form a broad network in the mediastinum testis, many fibres ending beneath the rete testis epithelium. Catecholaminergic fibres penetrated through the middle part of the cauda epididymis and formed a plexus in the albuginea covering the inferior testicular pole. This plexus gave rise to straight fibres which formed varicosities, some of them appeared related with mast cells. Actin-containing cells were only found beneath the rete testis epithelium. These cells were similar to myofibroblasts. The location of both cholinergic fibres and contractile cells among the rete testis channels suggests that these cells may be involved in the pumping of semen towards the ductuli efferentes and that their contractility may be regulated by cholinergic fibres.  相似文献   

13.
14.
Immunopathology of murine experimental allergic orchitis   总被引:11,自引:0,他引:11  
Experimental allergic orchitis (EAO) was induced consistently in BALB/c mice by immunization with homologous testicular tissue homogenate emulsified in complete Freund's adjuvant (CFA) providing that the animals had received simultaneously at least 1 microgram of an extract of Bordetella pertussis rich in pertussigen. All animals thus treated developed orchitis and serum antibody to testicular antigens within 20 days after immunization. The lesions were located in testis (100%), rete testis (37%), cauda epididymis (21%), and vas deferens (37%). Ductus efferentes and caput epididymis were only rarely affected. Early lesions in the seminiferous tubules were characterized by peritubular and/or intratubular accumulation of eosinophils, neutrophils, lymphocytes, and macrophages. This was followed by aspermatogenesis. Late lesions included massive necrosis and extensive fibrosis of the seminiferous tubules. Disruption of blood-testis barrier on day 20 was evidenced by the detection of 1) perfused lanthanum deposits between Sertoli cells and surrounding inflammatory cells inside the seminiferous tubules, 2) deposits of endogenous mouse IgG in germinal epithelium, and 3) probable immune complexes (granular C3) surrounding seminiferous tubules. Murine EAO differed from that of the guinea pig in the lack of involvement of the ductus efferentes, the extensive necrosis, the abundant polymorphonuclear eosinophils in the lesion, and the exquisite requirement of concomitant injection of B. pertussis extract.  相似文献   

15.
The structure of the human caput epididymidis was examined by gross morphological and light and electron microscopic techniques. There were at least seven types of tubules, each characterized by a different epithelium. These tubules were connected with one another by at least eight types of junctions to form a network. Most of the caput epididymidis was composed of efferent ducts. Within these, five types of tubules, each with a different ciliated epithelium, were found in different regions; and four types of junctions between the efferent ducts and the epididymal tubule were observed. The efferent ducts left the testis, initially as parallel straight tubules containing both ciliated and non-ciliated cells in an epithelium of irregular height. Each efferent duct then coiled tortuously into lobules that folded over one another. These efferent ducts then branched out as thin tubules to join a network of dark tubules which were lined by a regular epithelium containing prominently vacuolated, non-ciliated cells. These tubules anastomosed via common cavities characterized by a ciliated cuboidal epithelium and sometimes joined tubules exhibiting a non-vacuolated ciliated epithelium. The latter, as well as typical efferent ducts, made connection with the epididymis proper in both end-to-end and end-to-side junctions. In the more distal junctions with the epididymis, the efferent ducts joined to a transitional epididymal ductule before joining to the side of the epididymis proper. Post-junctional epithelia in the beginning of the epididymis occasionally contained patches of cells characteristic of efferent ducts. Tall cells with long stereocilia constituted a discontinuous "initial segment"-like region of the epididymis. This is the most detailed study so far of the epithelia and the tubule organization in the caput epididymidis of any species, and most of the results are reported for the first time for the human. Although the pattern of the tubule network resembles that of some domestic species, the rich variety of epithelia has not been appreciated before.  相似文献   

16.
In rats immunized systemically with tetanus toxoid the concentration of specific anti-tetanus-toxoid-specific IgG in fluid from the rete testis and cauda epididymidis were respectively 0.6% and 1.4% the concentration in blood serum. The extratesticular duct system reabsorbed 97% of the IgG and 99% of the fluid leaving the rete, but estradiol administration affected the site of reabsorption. In untreated rats, the ductuli efferentes reabsorbed 94% of the IgG and 96% of the fluid leaving the rete, whereas estradiol-treated rats reabsorbed 83% of the IgG and 86% of the fluid, and the ductus epididymidis fully compensated for these different effects of estradiol on the ductuli efferentes. The concentrations of IgG in secretions of the seminal vesicles and prostate gland were lower (0.1% and 0.3% respectively of the titers in blood serum) than in fluids from the extratesticular ducts, and were not affected by the administration of estradiol. RT-PCR showed that Fcgrt (neonatal Fc receptor, also known as FcRn) is expressed in the reproductive ducts, where IgG is probably transported across epithelium, being particularly strong in the ductuli efferentes (where most IgG was reabsorbed) and distal caput epididymidis. It is concluded that IgG enters the rete testis and is concentrated only 2.5-fold along the extratesticular duct system, unlike spermatozoa, which are concentrated 95-fold. Further, the ductus epididymidis can recognize and compensate for changes in function of the ductuli efferentes.  相似文献   

17.
Summary The vascular microarchitecture of the human testis and excurrent duct system was examined by use of a casting method combined with scanning electron microscopy. In the testicular parenchyma, the capillaries form a fine plexus around the seminiferous tubules. The commonly described rope-ladder-like pattern of the peritubular capillaries is absent in the human testis. The microvasculature of the rete testis consists of a poorly organized plexus. Throughout the epididymis including the ductuli efferentes, the peritubular capillary network encircles each tubule cylindrically. In the cauda epididymidis, a coarse venous network surrounds the capillary network externally. Small arteries of the epididymis not only penetrate the connective tissue septa, but also run along the surface. In the ductus deferens, three distinct microvascular systems are distinguished: (1) a venous network located in the connective tissue surrounding the muscular coat, (2) a microvascular plexus within the muscular coat, and (3) a peritubular capillary network. The plexus within the muscular coat interconnects the venous and the peritubular capillary networks.  相似文献   

18.
本文收集了19—38岁国人正常男性新鲜睾丸、附睾和输精管13例,进行了氧化还原酶组织化学染色、光镜定位及定性观察。结果表明:睾丸曲细精管和输出小管上皮的GDH,NADHD,NADPHD,SDH,GPDH,ICDH,MDH,LDH和G-6-PDH9种酶;睾丸间质细胞和附睾管上皮的NADHD,NADPHD,SDH,ICDH,MDH,GDH,LDH和G-6-PDH8种酶;输精管的NADHD,NADPHD,ICDH和GDH4种酶的酶活性呈强阳性或极强阳性。提示输出小管和头部附睾管含有的多种氧化还原酶对精子功能成熟有极重要作用。  相似文献   

19.
The permeability of Sertoli cell tight junctions to lanthanum administered during fixation has been compared in rats after ligation of the ductus deferens and after ligation of the ductuli efferentes. In both control and vasoligated testes, lanthanum penetrated only short distances into the Sertoli cell tight junctions before stopping abruptly. The tight junction, consisting of numerous pentalaminar fusions of contiguous Sertoli cell membranes, prevented diffusion of lanthanum into the adluminal compartment of the seminiferous epithelium. In rats with ligated ductuli efferentes, lanthanum completely permeated many Sertoli cell tight junctions and occupied intercellular spaces of the adluminal compartment. In spite of their newly acquired permeability to lanthanum, tight junctions retained characteristic ultrastructural features, including numerous membrane fusions. When lanthanum-filled tight junctions were sectioned en face, membrane fusions appeared as pale lines in lakes of electron-opaque tracer. These linearly extensive fasciae occludentes occasionally ended blindly, suggesting that lanthanum may have traversed the junction by diffusing around such incomplete barriers. The increased permeability of Sertoli cell tight junctions after efferent ductule ligation, which caused rapid testicular weight gain followed by atrophy, indicates that tight junctions are sensitive to enforced retention of testicular secretions inside the seminiferous tubules. The apparent normalcy of Sertoli cell tight junctions after vasoligation, which had no effect on testis weight, supports the view that blockage of testicular secretions distal to the epididymis is relatively innocuous.  相似文献   

20.
Over the past decade, studies on reproductive morphology in the Squamata (snakes and lizards) have expanded tremendously. With the accumulation of these studies and revisions of the terminology based on structural similarities and differences, it is imperative to review the work on tuataras to determine whether the structural organization fits the revised terminology of vertebrates. We investigated the morphology of the male reproductive system in the Tuatara, Sphenodon punctatus (Rhynchocephalia), the sister taxon to the Squamata. Previous studies on the Tuatara used a nomenclature for the testicular ducts different from the current terminology for amniotes. The reproductive system in the Tuatara is consistent with reports in the Squamata. Two rete testis tubules exit the testis within a connective tissue sheath similar to that shown in other squamate species and the protherian Echidna. Each rete testis divides into multiple ductuli efferentes that fuse with the epididymis. The epididymis transitions into the ductus deferens where the sperm become more concentrated into spherical bundles. The ductus deferens enters the cloacal urodeum separately from the ureter. An ampulla ureter or ampulla urogenital papilla was not observed, which differs from previous studies of lepidosaurians. Furthermore, a sexual segment of the kidney (SSK) was not observed, consistent with previous studies on the Tuatara.  相似文献   

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