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Localization of COX-2 in the male reproductive tract during sexual maturation.

Prostaglandins (PGs) are shown to influence sperm motility, contractility of the smooth muscle layers surrounding the seminiferous tubules and growth of both the seminal vesicle and the ventral prostate. PGs are produced by two distinct isoforms of cyclooxygenase (COX), including constitutively expressed COX-1 and inducible COX-2. To investigate the potential role of COX-2 in male reproductive tract maturation, we evaluated its expression in rats at pre-pubertal (14 days old), peri-pubertal (21, 28 and 35 days old) and post-pubertal (62 days old) stages. COX-2 was constitutively expressed in the initial segment of the epididymis, caput epididymidis and vas deferens at all stages of maturation. Its expression was mild in 14-day-old rats but its intensity markedly increased at 28 days and remained elevated afterwards. There was no COX-2 staining in the testis, rete testis, efferent ducts or cauda epididymidis. These data suggest that COX-2 derived PGs may be involved in the pubertal development of the epididymis, but not in the more apical regions of the excurrent duct system, including the rete testis and efferent ductules.

Journal Article↗

[Scanning electron microscopy of the human spermatic tract].

The human excurrent duct system of the testis (rete testis, ductuli efferentes, ductus epididymis and vas deferens) have been studied by the S.E.M. The specimens have been taken from subjects who underwent surgery for prostatic carcinoma. For the S.E.M. the specimens have been prepared according to usual techniques: fixed with 2.5% glutaraldehyde and 1% OsO4 in Millonig's buffer, dehydrated in ethanol, dried by the critical point technique in CO2 and coated with gold-palladium 10%. The cavities of the rete testis show a flat epithelium with short microvilli and single cilia. The ductuli efferentes are lined by long-ciliated columnar elements and by stubby elements provided with microvilli. Globular extrusions, probably representing the swollen apices of epithelial cells, have been interpretated like the expression of a secretory activity. The ductus epididymis is lined by high columnar epithelium provided with thick microvilli. In the lumen it is possible to observe little globular masses with variable diameters, isolated or more often grape-shaped. These have been interpretated as the expression of secretory activity microapocrine in nature. The vas deferens is bounded with columnar epithelial cells with variable morphology. Some of them, infact, have crowded microvilli, while some others have swollen apices bulging into the lumen. These globular extrusions are probably the expression of the secretory activity.

Epididymis↗

The effects of cyproterone acetate on the elements in the intraluminal fluids of the testis and epididymis of the rat.

Spermatozoal maturation and the integrity of the epididymis are dependent on the action of androgen. Micropuncture techniques and electron probe microanalysis were used to investigate the effect of cyproterone acetate on the concentrations of seven elements in intraluminal fluids of the testis, rete testis, and epididymis. After 4 weeks of treatment with cyproterone acetate, the sodium concentration rose in the corpus epididymidis (74.4 +/- 5.4 to 102 +/- 6 mmol/L, p less than 0.01). The concentration of potassium rose in seminiferous tubular fluid (33.9 +/- 2.7 to 49.4 +/- 4.4 mmol/L, p less than 0.01) and caput epididymidal fluid (15.9 +/- 1.4 to 25.7 +/- 0.9 mmol/L, p less than 0.01) after 8 weeks of cyproterone acetate treatment. The chloride concentration rose in the caput (23.7 +/- 0.8 to 65.4 +/- 12.5 mmol/L, p less than 0.01) and distal cauda (39.4 +/- 4.6 to 74.7 +/- 10.8 mmol/L, p less than 0.01) epididymidis after 8 weeks of treatment. Cyproterone acetate had no effect on the concentrations of phosphorus, calcium, and magnesium. The sulfur concentration rose in seminiferous tubular fluid (4.3 +/- 0.3 to 7.3 +/- 0.3 mmol/L, p less than 0.01) and distal cauda fluid (5.3 +/- 0.5 to 14.0 +/- 1.6 mmol/L, p less than 0.01) after 8 weeks of treatment with cyproterone acetate. Four weeks of treatment also increased the sulfur concentration in the distal cauda (6.8 +/- 1.6 to 13.4 +/- 1.5 mmol/L, p less than 0.01). Cyproterone acetate treatment did not affect the concentration of any element in rete testis fluid or serum.

Animals↗

Spatial topography of the excurrent duct system in the bovine testis.

The rete testis of the bull is situated within an axial mediastinum and consists of approximately 30 longitudinally arranged, anastomosing rete channels. At the cranial testicular pole all rete channels empty into a common space, the area confluens retis, which is subdivided by small septa and narrow chordae retis. The area confluens always contains numerous spermatozoa and is connected with the bulbous initial portions of the efferent ductules by short, often tortuous rete tubules. Since the connection between rete and efferent ductules is situated within the tunica albuginea, the bovine excurrent duct system is not provided with an extratesticular rete as in many other mammals. Straight testicular tubules merge from all directions to connect with superficial rete channels, but the inlets are not evenly distributed. In the periphery each straight tubule begins with a cup-like structure followed by a narrow stalk region and a heavily folded portion opening either immediately into a rete channel or into a tube-like lateral rete extension. In close contiguity to the rete testis lie extremely coiled arterial portions connecting the centripetal and the centrifugal branches of the testicular artery. Since intrinsic musculature is scarcely developed in the mediastinum, and transport of rete content relies primarily on massage due to external pressure changes, the pulsatile blood flow through these coiled arteries may influence conveyance processes within the rete testis. An intimate spatial association between area confluens retis and adjacent large, thin-walled lymph vessels may facilitate a transfer of androgens into the fluid of the rete testis.

Animals↗

Testicular tumors in mice exposed in utero to diethylstilbestrol.

Treatment of pregnant women with diethylstilbestrol (DES) is associated with the subsequent development of reproductive tract abnormalities such as epididymal cysts, retained hypotrophic testes and sperm abnormalities in their male offspring. It recently has been suggested that prenatal DES exposure is associated with development of testicular seminoma in humans. Studies of in utero exposure of laboratory animals to DES are few, but previous reports from our laboratory have described several abnormalities in the reproductive tract of the mouse following prenatal DES exposure. To study the possible association of testicular tumors and prenatal DES exposure in mice, pregnant outbred CD-1 mice were injected subcutaneously with daily doses of DES (100 micrograms./kg.) on days nine through 16 of gestation. DES-exposed and age-matched control male mice were sacrificed at 10 to 18 months of age and examined for testicular lesions. In addition to the nonmalignant abnormalities reported in previous studies such as 91% cryptorchidism and degenerative changes, interstitial cell tumors were observed in nine mice among 277 mice treated prenatally with DES. Two of these lesions were benign tumors and five were interstitial cell carcinomas. Rete testis adenocarcinoma was seen also in 5% of these DES-treated animals and is described in another report. The overall incidence of testicular tumors is 8% in DES-exposed male mice. No comparable lesions were seen in 122 control male mice. These results suggest that the testicular lesions that can occur following prenatal DES exposure include neoplasia. The combined prevalence of DES-induced tumors of the corpus testis and rete testis in mice suggests the male offspring may be more at risk for developing carcinoma of the reproductive tract than the female offspring.

Animals↗

The epididymis and its development in ratite birds (ostrich, emu, rhea).

The epididymis of ratitae is subdivided into a main part and a appendix epididymidis. The appendix epididymidis consists of the ductus aberrans and ductuli aberrantes. The ductus aberrans is the cranial continuation of the ductus epididymidis. The appendix epididymidis is cranially attached to the adrenal gland. In the main part of the epididymis the largest part of the rete testis is found. The rete testis is composed of an intratesticular rete (also named tubuli recti), and intracapsular rete (with a longitudinal cistern and a true rete), and an extratesticular rete (predominantly consisting of approximately 20 longitudinal channels). The rete testis develops most likely embryonally from buds of the glomerular capsules of the mesonephros. The ductuli efferentes proximales also from these capsules, while the ductuli efferentes distales develop from the proximal and distal tubules and intermediate-segments of the mesonephros. The ductus epididymidis originates from the Wolffian duct and meanders dorsolaterally through the epididymis.

Animals↗

Mode of migration of normal lymphocytes inside murine testis.

BACKGROUND: Previous studies have shown that in murine experimental autoimmune orchitis (EAO), lymphocytes preferably infiltrate into (1) the testicular capsule near the rete testis, (2) the subcapsular interstitium away from the rete testis, and (3) the interstitium surrounding the tubuli recti and rete testis. Therefore, these three sites might provide tissue environments in which specific lymphocytes can easily gain access to testicular autoantigens. However, there is another possibility that infiltrating lymphocytes in the testis spontaneously accumulate at these three sites via the lymphatic flow inside this organ during EAO. METHODS: To examine this possibility, normal lymphocytes were locally injected into the peripheral testis regions of recipient mice. Testes were then collected at various times for investigating the chronological pattern of lymphocytic migration inside the testes at a light microscopic level. RESULTS: The injected lymphocytes first stayed in the lymphatic space around the seminiferous tubules and then moved to the subcapsular lymphatic space away from the rete testis. The lymphocytes accumulated under the testicular capsule and then gradually infiltrated into the adjacent capsular tissue. In the capsule, the cells surrounded the arteriolae and then accumulated in the capsular tissue near the rete testis. Thereafter, the cells finally left the testes through the lymphatics running in the spermatic cords. In the course of the lymphocytic drainage, it was noted that the injected lymphocytes appeared not to pass through the testicular interstitium around the tubuli recti and rete testis. CONCLUSIONS: The regional distributions of the testicular lymphocytes imply that the lymphatic flow in the testis may somewhat influence murine EAO pathology characterized by lymphocytic accumulation in (1) the testicular capsule near the rete testis and (2) the subcapsular interstitium away from the rete testis. However, the pathology exhibiting lymphocytic accumulation in (3) the interstitium around the tubuli recti and rete testis is independent on the intratesticular lymph flow.

Animals↗

Sertoli cells secrete both testis-specific and serum proteins.

The secretions of the Sertoli cell were examined with two polyvalent antisera--one prepared against proteins in rat serum and the other against testis-specific proteins in rete testis fluid. These antisera detected 12 serum and 9 testis-specific proteins in rete testis fluid. To determine the origin of these proteins, primary cultures enriched in Sertoli cells were incubated with [35S]methionine, and the radiolabeled proteins in the medium were immunoprecipitated. Gel electrophoresis of the two immunoprecipitates resolved eight serum and nine testis-specific proteins. These two sets of proteins were specifically bound to their respective antiserum and were immunologically distinct. Medium from Sertoli cell cultures contained 10 times more of the testis-specific proteins than did cultures enriched for testicular myoid or interstitial cells. The concentration of the serum proteins in Sertoli cell medium was 5 and 10 times greater, respectively, than in myoid or interstitial cell preparations. The proteins from Sertoli cells were next characterized on two-dimensional gels. Seven of the proteins recognized by antiserum against serum proteins had identical molecular weights and isoelectric points as serum proteins. Three of these proteins were ceruloplasmin, transferrin, and glycoprotein 2. In addition to the proteins immunoprecipitated by the two antisera, more than 60 other proteins were detected on two-dimensional gels of the total secretory proteins. We conclude that the Sertoli cell secretes many proteins, some of which are specific to the testis and others of which are similar to serum proteins.

Animals↗

Immunohistochemical demonstration of myoid cells in the testis and its excurrent ducts in the domestic fowl.

(1) Immunohistochemical methods and three antibodies (against actin, desmin and smooth muscle actin) were used to demonstrate the myoid cells in the domestic fowl testis and its excurrent ducts. (2) A positive reaction to actin, smooth muscle actin and desmin was found in the myoid cells of peritubular tissue of the testis and in rete testis, ductuli efferentes and ductus epididymidis. (3) In the testis myoid-reactive cells form a single layer. In the rete testis, ductuli efferentes and the ductus epididymidis reactive myoid cells form a main component of the stroma. (4) Positive reaction to actin, smooth muscle actin and desmin was also observed in the myoid cells of the tunica albuginea and in the wall of blood vessels in the testis and epididymis, indicating a contractile function for the testicular capsule.

Actins↗

Expression of the clusterin gene in the tissues of Booroola sheep which were homozygotes or non-carriers of the fecundity gene FecB.

Clusterin or sulphated glycoprotein-2 is a major component of the rete testis fluid, synthesized by the rete testis epithelial cells and Sertoli cells. Differences in the two-dimensional polyacrylamide gel electrophoresis pattern of clusterin-like proteins have been reported in rete testis fluid from Booroola rams carrying the fecundity gene FecB, when compared with that from non-carrier rams. In order to determine whether the FecB gene influences the expression of the clusterin gene, we used a rat clusterin cRNA probe to investigate mRNA species in the tissues of homozygous (BB) or non-carrier (++) Booroola sheep. Northern blots of polyadenylated RNA showed hybridization to the cRNA probe in the testis, ovarian follicles, corpora lutea and stroma, pituitary and liver. A major mRNA transcript was observed at 2.3 kb and a minor transcript in some tissues at 0.8 kb. Densitometry of the autoradiographs revealed no FecB-specific differences in the densities of the hybridization signals from ++ and BB testis or ovarian follicle, corpora lutea or stromal RNA. We conclude that the gene for ovine clusterin is expressed widely in the tissues of sheep and that its expression is not affected by the presence of the FecB gene.

Animals↗

Histological studies on the testicular seminal pathway and changes in the epididymis of the camel (Camelus dromedarius). Part IV.

The testicular seminal pathway in the camel is divided into two portions: an intratesticular and an extratesticular portion. The intratesticular seminal pathway consists of three portions: a 'tapering terminal segment' of the seminiferous tubules opening into the receptacle, the tubuli recti with three parts and the rete testis. The extratesticular portion consists of the rete testis, as an extension of the intratesticular portion and an elongated sac from which 6-7 ductuli efferentes originated. The tapering terminal segments are lined by modified Sertoli cells. Both, the tubuli recti and rete testis, are lined by simple cuboidal to columnar cells. The epithelium of the ductuli efferentes which, at its origin from the sac is simply cuboidal, gradually changes to an epithelium that consists of alternating groups of high-columnar ciliated and low-columnar non-ciliated cells. The strongly PAS-positive basement membrane of the ductuli efferentes is surrounded by a thin circular layer of smooth muscle fibres. The pseudo-stratified columnar epithelium of the epididymis is supported by an intensely PAS-reactive basement membrane. Morphological changes in the epithelium of the head and body regions of the epididymis due to seasonal variations are well marked in the camels of all age groups.

Age Factors↗

Histochemistry and ultrastructure of nerve fibres and contractile cells in the tunica albuginea of the rat testis.

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.

Acetylcholine↗

Changes in distribution of phosphomannosyl receptors during maturation of rat spermatozoa.

The aim of the present work was to study the distribution of the cation-independent (CI) and cation-dependent (CD) mannose-6-phosphate receptors (MPRs) in spermatozoa obtained from either rete testis or three regions of rat epididymis. We observed that both receptors underwent changes in distribution as spermatozoa passed from rete testis to cauda epididymis. CI-MPR was concentrated in the dorsal region of the head in rete testis sperm and that this labeling extended to the equatorial segment of epididymal spermatozoa. CD-MPR, however, changed from a dorsal distribution in rete testis, caput, and corpus to a double labeling on the dorsal and ventral regions in cauda spermatozoa. The percentages of spermatozoa that showed staining for either CI-MPR or CD-MPR increased from rete testis to epididymis. The observed changes were probably the result of a redistribution during transit rather than an unmasking of receptors. The fluorescence corresponding to CD-MPR and CI-MPR on the dorsal region disappeared when caudal spermatozoa underwent the acrosomal reaction. Receptors were localized on the plasmalemma of spermatozoa, as observed by immunoelectron microscopy. Changes in distribution may be related to a maturation process, which suggests new roles for the phosphomannosyl receptors.

Animals↗

Intertubular growth in pure seminomas: associations with poor prognostic parameters.

Clinical stage I seminomas are effectively treated with surgery raising concerns as to when to give adjuvant radiation therapy given the risk of secondary malignancies. A recent randomized trial found tumor size and rete testis invasion to be the strongest predictors of relapse in clinical stage I seminomas. These 2 parameters may be surrogate measures of tumor volume. Intertubular seminoma (ITS) of the testis describes the presence of neoplastic germ cells within the interstitium of the testis. These cells are detected away from the main macroscopic mass. Because ITS can infiltrate in a 3-dimensional fashion, it may also represent a measure of tumor volume not usually noted in standard pathology reporting. The goal of this study was to determine the incidence of ITS in pure seminomas and its association with other prognostic parameters. One hundred twenty consecutive pure seminomas surgically removed between 1998 and 2003 were evaluated. ITS was defined as the presence of an interstitial or intertubular growth pattern of tumor cells, which was noncontiguous with the main tumor and present at least 3 high-power fields away from the tumor mass. The average tumor size was 3.4 cm. Of the entire cohort of patients, which included pathological stages T1 through T3, 11% had invasion through the tunica albuginea, 51% had rete testis invasion, 51% had lymphovascular invasion, 93% had associated intratubular germ-cell neoplasia, and 36% had ITS. ITS was significantly associated with rete testis invasion ( P = .001). Logistic regression analysis looking at ITS, tumor size, patient age, and lymphovascular invasion revealed that only ITS was associated with rete testis invasion (RR, 4.1, P < .0001). ITS is present in a significant proportion of pure seminomas and has a significant association with rete testis invasion. The presence of ITS may therefore be an important prognostic factor, not only because it alters the calculated size of the tumor but also because it has an association with rete testis invasion.

Adult↗

Regional differences in luminal fluid polypeptides of the rat testis and epididymis revealed by two-dimensional gel electrophoresis.

Luminal fluid samples were collected by micropuncture of the seminiferous tubule, rete testis, and defined levels of the epididymal tubule. After removal of spermatozoa by centrifugation, the supernatant fluids were analyzed by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) and an ultrasensitive silver staining procedure to define the sequential change in protein composition along the excurrent duct system. Fluid from each segment displayed a characteristic 2-D PAGE map composed of numerous polypeptides. Seminiferous tubule fluid contained a wide array of polypeptides, with most concentrated in the 45 Kd to 90 Kd range, but, in contrast, rete testis fluid lacked most of these polypeptides. The major complex of rete testis fluid comigrated with serum albumin and was present in all distal segments. Other major rete testis components were not noted distally. Fluid from the caput was characterized by new major components of 30 to 37 Kd, 28 to 30 Kd, 24 Kd, and 23 Kd, each of which consisted of multiple spots of apparent isoelectric variants; all except the 30 to 37 Kd complex were present in the fluid from more distal segments. Proceeding distally, there was a temporal appearance of new polypeptides, especially in the molecular weight range below 30 Kd. Two-dimensional PAGE analysis of detergent extracts of washed spermatozoa indicate that a specific subset of these fluid polypeptides are sperm associated.

Animals↗

Effects of follicle-stimulating hormone on inhibin release by different testicular compartments in the adult ram.

The aim of this study was to determine the bidirectional release of immunoreactive inhibin-alpha (irINH-alpha) by different testicular compartments in the adult ram and to assess the effects of FSH on the distribution of inhibin in the testis. Immunoreactive INH-alpha was measured by RIA in fluid samples collected concurrently from the three testicular compartments--the seminiferous tubules, the interstitium, and the vascular system--through catheters inserted surgically into the rete testis, testicular lymphatic duct system, and spermatic veins, respectively. Overall, the concentration of irINH-alpha in rete testis fluid was 25 times the level in testicular lymph and over 500 times the concentration in peripheral blood. The pattern of irINH-alpha concentration in rete testis fluid was inversely related to that in testicular lymph, but i.v. administration of FSH had a decoupling effect on this relationship by depressing inhibin concentration in testicular lymph without affecting inhibin levels in rete testis fluid. Nevertheless, increased flow of testicular lymph more than compensated for the transient fall in irINH-alpha concentration so that, overall, the total output of inhibin via the testicular lymphatic duct system (and the vascular system) increased significantly. No persistent or significant changes were observed in the flow rate of rete testis fluid or concentration of irINH-alpha in the fluid after administration of FSH. The time frame for the response of the testis to FSH is indicative of the involvement of a mediator. Electrophoretic analysis of serially collected testicular lymph samples consistently revealed an FSH-induced release of a series of proteins in the M(r) range of 30,000-32,000.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Major contribution of epididymis to alpha-glucosidase content of ram seminal plasma.

Acid alpha-glucosidase and L-carnitine (a well-known epididymal marker) were measured in rete testis and epididymal fluids of adult male rams. These fluids were collected by selective catheterization or by a micropuncture technique, respectively. Both parameters remained at a low and constant level in rete testis and all along caput and corpus epididymidis. Then they increased at equivalent rates in cauda epididymidis to much higher levels than those in seminal plasma (5 mU/mg protein and 10 mM, respectively). An optimum pH study of alpha-glucosidase activity in these fluids showed two well-separated peaks in rete testis and caput epididymal fluids around pH 4 and 7, respectively, but only a single peak at pH 4 in cauda epididymidis that was comparable to the one in seminal plasma. Sucrose density gradient fractions analyzed for their enzyme content in the absence or presence of sodium dodecyl sulfate (1% w/v), a selective inhibitor of acid alpha-glucosidase activity, allowed the demonstration of two enzyme forms at pH 6.8 in rete testis fluid sedimenting in the 7S and 4S regions of the gradient, while a unique 4S form was encountered in cauda epididymidis and in seminal plasma. Although the fate of the minor 7S component of the rete testis fluid in its epididymal transit is presently unknown, similarities between the enzyme in cauda epididymidis and seminal plasma are strong enough to support the hypothesis that epididymis contributes primarily to the acid alpha-glucosidase content of ram seminal plasma.

Animals↗

The effect of epididymal and testicular fluids on the fertilising capacity of testicular and epididymal spermatozoa.

It is possible that the fertilising capacity of spermatozoa in the epididymis is influenced by the epididymal secretion. We have studied this problem by obtaining spermatozoa before entry into the epididymis and after passage through it, incubating both types of spermatozoa in fluids from the rete testis and cauda epididymidis and then checking their fertilising capacity. While spermatozoa from the rete testis were infertile, rete testis fluid did not decrease the fertilising capacity of epididymal sperm from the cauda epididymidis. Fluid from the cauda epididymidis did not promote the fertilising capacity of testicular spermatozoa. These results are discussed in the light of the current understanding of epididymal physiology.

Animals↗