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At least 19 recordsLinked to original sources

Postnatal differentiation of the ductus deferens, tail of the epididymis, and distal body of the epididymis in goats occurs independently of rete testis fluid.

Observations from extratesticular rete-ligated, mature goats indicated that epithelial morphology in the tail of the epididymis can be maintained without any input from testicular fluid (Goyal et al., Acta Anat., 1994;150: 127-135). Hence, the objective of this study was to determine whether the tail of the epididymis and/or other regions of the male excurrent ducts can differentiate prior to the appearance of lumen in the seminiferous tubules, which is an indicator for the onset of seminiferous tubular fluid secretion. Based on age and scrotal circumference (SC), 20 male goats were divided into four groups of five animals each: 1-4 weeks (SC, 6.5-7.5 cm), 7-10 weeks (SC, 8.5-11.0 cm), 12-15 weeks (SC, 11.0-14.0 cm), and 15-25 weeks (SC, 16.0-19.0 cm). Tissues were collected from the testis, six regions of the epididymis (proximal, middle and distal head; proximal and distal body; and tail), and the ductus deferens, and were processed for light and electron microscopic examination. Changes in epithelial height and cytological features associated with absorption (microvilli, pinocytotic and coated vesicles) and protein secretion (RER, Golgi body) were used as markers for differentiation. Differentiation of all of these features was comparable to that observed in the 15-25-week-old animals in the ductus deferens by > or = 1 week, in the tail of the epididymis by > or = 7 weeks, in the distal body of the epididymis by > or = 12 weeks, and in the proximal body of the epididymis and all three regions of the head of the epididymis by > or = 15 weeks. Seminiferous tubules developed lumens between 12 and 15 weeks. In conclusion, epithelial differentiation in the ductus deferens, tail of the epididymis, and distal body of the epididymis follows a time-dependent, spatial, ascending order and is achieved before lumen formation in the seminiferous tubules. Conversely, epithelial differentiation in all three regions of the head and the proximal body of the epididymis occurs simultaneously and after lumen formation in the seminiferous tubules.

Age Factors↗

Cloning of complementary DNA encoding a 135-kilodalton protein secreted from porcine corpus epididymis and its identification as an epididymis-specific alpha-mannosidase.

In the preceding study (Okamura et al., 1992; Biol Reprod 47:1040-1052) we suggested that a 135-kDa protein secreted by porcine epididymis is involved in the sperm maturation. In this work, we have isolated the cDNA clone coding the 135-kDa protein in an effort to investigate its structure and function. The 135-kDa protein was purified from porcine cauda epididymal fluid. Three oligonucleotide probes were synthesized according to the amino acid sequences of N-termini of the native protein and trypsin-digested peptides. A cDNA clone hybridizing with these three probes was isolated from the cDNA library derived from the porcine proximal corpus epididymis. It encodes a novel protein with 1,006 amino acid residues in an open reading frame. Its overall amino acid sequence was significantly homologous (25.7%) to the alpha-mannosidase precursor of Dictiostelium discoideum (P34098). The 135-kDa protein could digest both p-nitro-phenyl-alpha-D-mannoside and high mannose oligo saccharide (Man8-GlcNAc2), strongly suggesting that it is an alpha-mannosidase homologue. The expression of this protein was specific to porcine and was localized to the very narrow parts of epididymis: the border of the caput and corpus epididymis. This protein may serve as a good marker for the functional differentiation in porcine epididymis. A possible role of this protein in the species-specific sperm-egg interaction is discussed.

Amino Acid Sequence↗

Kinetic analysis of rat steroid 5alpha-reductase activity in prostate and epididymis homogenates at neutral pH: evidence for type I activity in epididymis.

Immunocytochemical studies and mRNA measurements have shown that the rat epididymis--like the rat prostate--expresses both rat steroid 5alpha-reductase isozymes, i.e. type I and II. So far, enzyme activity measurements in rat epididymis homogenates, however, do not support the presence of type I 5alpha-reductase activity. Incubating homogenates of both tissues with a wide range of substrate concentrations, we were able to detect activity of both isozymes in rat prostate and epididymis tissues at neutral pH. In rat prostate the amount of type I activity, as measured by the Vmax at pH 7.0, exceeds that of type II 5alpha-reductase 50-fold. The efficiency ratio, Vmax/Km, of the type I isozyme accounts for 25% of the total in vivo potential activity. A possible anabolic role for the type I isozyme in rat prostate was thus surmised. In rat epididymis the Vmax of type I and type II 5alpha-reductase at pH 7.0 were similar. Comparison of the efficiency ratio Vmax/Km of either isozyme in the rat epididymis, however, suggested that the type II isozyme would play the major role in the 5alpha-reduction of testosterone at physiological concentrations and at neutral pH. The specific localization of the isozymes should be considered to allow for correct quantification of their in vivo contribution to dihydrotestosterone formation.

Animals↗

Morphology of the epididymis of the cock (Gallus domesticus) and its effect upon the steroid sex hormone synthesis. I. Ontogenesis, morphology and distribution of the epididymis.

The epididymis of the cock is divided into a main part and an appendix epididymidis. The main part of the epididymis is firmly connected to the testis. The sperm transporting tubes open into the ductus epididymidis along its entire length. The rete testis, as the most proximal part of the epididymis, develops from mesenchym cells. The rete testis connects the tubuli seminiferi with the ductuli efferentes proximales which develop from the Bowman's capsules of the mesonephros. The ductuli efferentes distales develop from the proximal tubules, conducting segments (loops of Henle), and the distal tubules of the mesonephros. The short ductuli conjugentes which open into the ductus epididymidis, originate from the connecting segments of the mesonephros. In the sexually mature cock the rete testis, the ductuli efferentes proximales, and the ductus epididymidis all show an enlargement in the lumen. In the ductuli efferentes proximales and in the ductus epididymidis one can observe a formation of globuli and cell protrusion which lead to a loss of the surface structure of the epithelial cells. The appendix epididymidis and the capsula fibrosa of the adrenal gland are joined by connective tissue. The appendix epididymidis consists of the blindly ending ductus aberrans (the crainal continuation of the ductus epididymidis) and the ductuli aberrantes which open into the ductus aberrans. The blind ends of the ductuli aberrantes end in the capsula fibrosa of the adrenal gland.

Animals↗

The effect of non-union of testis and epididymis and of cryptorchidism on the development of epididymis and ductus deferens in the rat.

16-days old rats were operated with either uni- or bilateral ligation of ductuli efferents and separation of testis and epididymis to the level of the inferior epididymal artery (non-union operation), induction of cryptorchidism or bilateral sham operation. The epididymides were weighed and the epididymides and deferent ducts were examined with light- and electron-microscopy at days 30, 37, 44 and 58. Bilateral non-union operated epididymides and cryptepididymides had a significantly lower weight increase than controls, but the histology and diameter of epididymal tubules were unchanged. This indicates a true growth retardation and reduced length of epididymal tubules of non-union operated and cryptepididymides. For bilateral operations a positive correlation was found between the weight of epididymis and plasma levels of total testosterone as reported earlier. Unilaterally operated epididymides had a weight development significantly below contralateral controls, despite normal plasma levels of testosterone. It is concluded that the reduced-weight of unilaterally operated epididymides is the result of diminished local androgen stimulation from the ipsilateral testis. Non-union of testis and epididymis may have pathogenetic significance in maldescent of testis by a retarded growth of the ductal system.

Animals↗

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

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

Epididymis↗

Studies on the physiology and biochemistry of mammalian epididymis: effect of flutamide, a nonsteroidal antiandrogen, on the epididymis of the rat.

The effect of flutamide (Sch 13521; 4'-nitro-3'-trifluoromethylisobutyranilide), a nonsteroidal antiandrogen, on male rat genital organs was studied. Administered at a dose of 25 mg/kg body weight daily for 30 days, flutamide caused a significant increase in the weight of the testis but had no effect on spermatogenesis and Leydig cell morphology. The secretory activity of the epididymis, as evidenced by the level of glycerylphosphoryl-choline and sialic acid, either remained unaffected or was stimulated. There was a significant decrease in seminal vesicle and ventral prostate weight and in the fructose content of the coagulating gland. The anti-androgen at the dose used did not affect the fertility of the rats. The significance of these findings is viewed in relation to the hypothesis of a differential threshold requirement of androgen for the epididymis and the accessory sex glands. The potentiality of antiandrogens as extragonadal antifertility agents in the male is discussed.

Anilides↗

Distribution of 5 alpha-reductase in the epididymis of the tammar wallaby (Macropus eugenii) and dependence of the epididymis on systemic testosterone and luminal fluids from the testis.

The activity of 5 alpha-reductase was much higher in the caput and corpus epididymidis than in the cauda epididymidis. Orchidectomy caused a reduction in 5 alpha-reductase activity in the caput and corpus epididymidis, and regression of the epithelium and reduction in mass of all regions of the epididymis. Subsequent testosterone therapy caused a substantial increase in amount of epithelium and overall mass of the cauda epididymidis but showed little or no increase in any of the responses measured in the caput and corpus epididymidis. We concluded that the caput and corpus epididymidis of the tammar respond to factors other than testosterone, probably some constituent in the luminal fluid, and therefore are homologous with the initial segments of the epididymis in eutherians.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

Androgen-binding proteins in sheep epididymis: characterization of a cytoplasmic androgen receptor in the ram epididymis.

An androgen receptor (Rc) was demonstrated in caput, corpus and cauda epididymal cytosols of the ram. This receptor had a high affinity for 5 alpha-dihydrotestosterone (Kd = 5.2 X 10(-9) mol/l) and could be distinguished from the androgen-binding protein (ABP) by several characteristics. On polyacrylamide-gel electrophoresis, Rc had a mobility of 0.37 and ABP 0.61; Rc sedimented in the 9S region of a linear sucrose gradient whereas ABP migrated in the 4.3S region; the molecular weights were 192 000 and 90 000 for Rc and ABP; their isoelectric points were 5.7 and 4.8-5.0; they were proteinaceous components since they were destroyed by proteolytic enzymes and heating (50 degrees C for Rc and 60 degrees C for ABP); they exhibited different half-times of dissociation:20 h at 0 degree C for Rc and 6 min for ABP, which is in agreement with their respective physiological roles, intra- and extracellular transport of androgens. The content of Rc-binding sites in caput epididymis was 18, in corpus 4 and in cauda 22 fmol/mg protein.

Androgen-Binding Protein↗

Testis and epididymis of the Indian wall lizard (Hemidactylus flaviviridis): effects of flutamide on FSH and testosterone influenced spermatogenesis, Leydig cell, and epididymis.

To determine the separate spermatogenic actions of FSH and testosterone, adult male lizards Hemidactylus flaviviridis with recrudescent testes were administered the non-steroidal antiandrogen flutamide either alone or in combination with FSH or testosterone, and the histology and histochemistry of the testes and ductus epididymides were studied. Flutamide-treated animals displayed a marked hypertrophy of Leydig cells. A few spermatids were also seen in testis of more than half the animals treated with flutamide. Flutamide also produced a significant increase of primary spermatocytes; no spermatids were observed in controls. A significant inhibition of spermatogenesis was noted in lizards treated either with testosterone alone or in combination with flutamide. Ovine FSH treatment caused a significant stimulation of spermatogenesis, as indicated by the increase of primary and secondary spermatocytes and the transformation of secondary spermatocytes into spermatids or, in a few cases, into spermatozoa. A considerable depletion of sudanophilic lipid and moderate delta 5-3 beta-hydroxysteroid dehydrogenase activity was noted in the Leydig cells of FSH-treated animals indicating enhanced steroidogenesis. Similar results were obtained when lizards were treated with flutamide + FSH. The effects of simultaneous treatment of flutamide with FSH or testosterone on ductus epididymidis revealed that flutamide markedly inhibited the epithelial cell height and lumen diameter with a loss of luminal content when compared to FSH or testosterone-treated lizards.

Animals↗

Rat epididymis-specific sperm maturation antigens. I. Evidence that the 26 kD 4E9 antigen found on rat caudal epididymal sperm tail is derived from a protein secreted by the epididymis.

Monoclonal antibody 4E9, which was raised against a partially purified detergent extract of rat caudal epididymal sperm, recognizes the tail of sperm from the cauda, but not from caput epididymidis, as well as epithelial cells in a restricted region of the distal caput/corpus epididymidis and proteins in epididymal fluid from corpus and cauda epididymidis. The antigen is apparently a glycoprotein, since it is retained on a Ricinus communis agglutinin I lectin column. Epididymal fluid antigens have apparent M(rs) of 38-26 kD, whereas the membrane-associated form of the molecule has an M(r) of 26 kD. Immunocytochemical data and Western immunoblot data suggest that the membrane antigen is derived from the fluid antigen, which, in turn, is secreted by the epididymal epithelium. Characterization of the membrane antigen indicates that it is tightly associated with the sperm surface, behaving as though it is an integral membrane protein. The antigen persists on ejaculated sperm.

Animals↗