Regional Differences in Steroidogenesis and Hormone Levels in the Epididymis and Vas Deferens of Adult Rats

In vivo and in vitro studies with different parts of the epididymis and vas deferens were carried out to determine their inherent capacity to synthesize steroids and to correlate with the endogenous levels with or without the administration of hCG.
Incubation with ¹⁴C-labelled pregnenolone and testosterone demonstrated that caput epididymidis was more active than other parts in synthesizing testosterone from ¹⁴C-pregnenolone and in converting labelled testosterone to 5α-dihydrotestosterone (DHT). The cauda epididymidis and vas deferens accumulated more radioactivity in progesterone and dehydroepiandrosterone (DHEA) than the caput epididymidis.
The levels of DHT, testosterone and 4-androstene-3,17-dione in the caput epididymidis were reduced after ligation of ipselateral efferent ductules indicating the testicular origin of these steroids. The cauda epididymidis and vas deferens had higher levels of progesterone as compared to the other regions of the epididymis, which were decreased after the ligation. Intravenous injection of hCG increased the levels of oestradiol-17β in all tissues and markedly in the cauda epididymidis and vas deferens. The high levels of progesterone and oestradiol-17β present in these organs may be of importance in maintaining fertilizing ability of spermatozoa stored in the cauda epididymidis and vas deferens and their transport.     

Differential expression and regulation of integral membrane protein 2b in rat male reproductive tissues

Aim： To examine the expression and regulation of integral membrane protein 2b （Itm2b） in rat male reproductive tissues during sexual maturation and under different treatments by in situ hybridization. Methods： Testis, epididymis, and vas deferens were collected on days 1-70 to examine Itm2b expression during sexual maturation. To further examine the regulation of Itm2b, adult rats underwent surgical castration and cryptorchidism. Ethylene dimethane sulfonate and busulfan treatments were carried out to test the regulation of Itm2b after destruction of Leydig cells and germ cells. Results： In testis, Itm2b expression was moderately detected in the adluminal area of seminiferous cords on days 1-10, and detected at a low level in the spermatogonia on days 20 and 30. The Itm2b level was markedly increased in Leydig cells from day 20 to day 70. In epididymis and vas deferens, Itm2b was detected from neonate to adults, and the signal gradually increased in accordance with sexual maturation. Itm2b expression was significantly downregulated in epididymis and vas deferens of castrated rats, and strongly stimulated when castrated rats were treated with testosterone. Cryptorchidism led to a significant decline of Itm2b expression in testis and caput epididymis. Itm2b expression in epididymis and vas deferens was significantly decreased after the Leydig ceils were destroyed by ethylene dimethane sulfonate. Busulfan treatment produced no obvious change in Itm2b expression in epididymis or vas deferens. Conelusion： Our data suggested that Itm2b expression is upregulated by testosterone and might play a role in rat male reproduction.     

Selective action of androgens on the molecular forms of esterases characterized by two-dimensional gel electrophoresis in the epididymis and vas deferens of the mouse

Molecular forms of esterases were resolved in non-denaturing conditions by using two-dimensional gel electrophoresis with isoelectric focusing in the first dimension and a time-dependent polyacrylamide gradient gel electrophoresis (PAGGE) in the second dimension. This procedure was used to analyse sequential changes in esterase composition along the excurrent genital duct of the mouse and to initiate a specific identification of the androgen-regulated molecular forms. Almost all the 68 variants (pH 3.9-6.4 and 50-300 kDa) revealed by alpha-naphtyl acetate from the fluids of the three parts of the epididymis (caput, corpus, cauda) and vas deferens, could be assigned to the carboxylesterase group as shown by their action on various substrates and sensitivity to inhibitors. Some of these variants co-migrated with those in the serum and testis, whereas other enzyme forms made their first appearance in the caput (13), in the corpus (26) and in the vas deferens (3). The major changes occurred between the caput and the corpus of the epididymis. Only a few acidic spots were not revealed after neuraminidase digestion. Castration of mice (4 weeks) resulted in inhibition of the activity of 34 esterase forms, and thus abolished most of the regional differences in the excurrent duct system. By re-initiating or repressing the synthesis of regional esterase variants, testosterone supplementation (2 and/or 4 weeks) of castrated animals restored the normal esterase pattern in the three epididymal parts, but not in the vas deferens. The major effect of efferent duct ligation (4 weeks) was the emergence in the corpus and cauda of the epididymis of two variants found in the caput of uncastrated mice.     

Zinc content in the epididymis, vas deferens, prostate, and seminal vesicles of juvenile rhesus monkey (Macaca mulatta): effect of androgen and estrogen

The zinc content in the three segments of the epididymis (caput, corpus, and cauda), vas deferens, seminal vesicles, and prostate of juvenile monkeys was determined by atomic absorption spectrophotometry. Zinc content (micrograms/gm wet weight) was found to be maximum (328) in the vas deferens; in the other organs it measured in the following order: caput 191, corpus 238, cauda 193, prostate 133 and seminal vesicles 85. In order to investigate the endocrine control of the zinc in these organs, two groups of animals were treated with testosterone propionate (2 mg) or estradiol dipropionate (10 micrograms) once daily for 30 days. In response to androgen, a rise in both concentration and content of zinc was evident only in the prostate. The results further suggested that the prostatic zinc may be under dual hormonal control, but in the epididymis and vas deferens it may be under the influence of estrogen. It is concluded that the hormonal effects on zinc content and growth stimulation in accessory sex organs are quite separate and may be under different hormonal control.     

The maturation of sperm motility in the epididymis and vas deferens of the vervet monkey, Cercopithecus aethiops

Among the diverse facets of sperm maturation, changes in motility are conspicuous and hence studies of sperm kinematics might provide good indices for sperm maturation. Accordingly, the maturation of sperm motility in the epididymis and vas deferens of the vervet monkey, Cercopithecus aethiops, was assessed using a computer-aided sperm motility analysis system. The results revealed clear trends in the development of both sperm motility per se and in the movement characteristics of motile spermatozoa from different regions of the epididymis, the vas deferens and the ejaculate, reflecting maturational changes associated with the attainment of functional motility and fertility. Motion of spermatozoa from the caput epididymis was sluggish and irregular. As the spermatozoa moved through the corpus epididymis, motility increased sharply, and continued to improve through the cauda epididymis and vas deferens. Despite the high proportion of motile cells, full maturation of motion capabilities was not completed in spermatozoa from the corpus epididymis. Only once spermatozoa had reached the cauda epididymis and vas deferens did they attain their full vigour, and swam rapidly (greater VCL, VSL and VAP) with straightline trajectories (greater LIN, WOB and STR; lower ALH, MAD and CURV). After acquiring their maximal percentage motility and progressive velocity in the cauda epididymis and vas deferens, a slight decline in motility and vigour occurred in ejaculated spermatozoa, and was possibly associated with the ageing of stored spermatozoa. The results from this investigation have revealed clear trends in the maturation of the motility of vervet monkey spermatozoa during their transit through the epididymis and vas deferens and final emergence in the ejaculate, and have provided crucial baseline information on the reproductive physiology of this potentially valuable biomedical model to serve as a reference for future studies in reproductive toxicology.     

Identification and androgen-dependence of proteins in the mouse vas deferens

Proteins from 'luminal fluid' or from a homogenate of whole vas deferens were analysed by polyacrylamide gel electrophoresis under denaturing conditions. Four major bands with apparent molecular weights of 34.5, 36, 38 and 180 Kilodaltons (K) were observed in homogenates. In 'luminal fluid' the same protein pattern was observed except that 38 K band was missing. These four major bands probably originated from the vas deferens as they were not detected in plasma and were still present after ligation between the epididymis and vas deferens. After castration, there was a specific reduction of the 34.5 K MW protein band in both homogenate and 'luminal fluid'. When the androgen-dependence of proteins was investigated using radioactive methionine, the protein spectra from normal and castrated males showed that about 10 polypeptides were differentially induced or repressed by androgens. The synthesis of some proteins (MW's 24, 36 and 180 K) was decreased by castration while the synthesis of several others (MW's between 27 and 82 K) was increased. Most of these androgen-dependent proteins were detectable at 10 days of age.     

Alteration of epididymal function and its relation to maturation of spermatozoa

Alteration of epididymal function and its relation to maturation of spermatozoa was studied in 54 adult male albino rats. Levels of free and bound sialic acid in the spermatozoa and luminal contents of the epididymis and vas deferens were determined. A group of 10 received rabbit antiserum to ovine luteinizing hormone (LHAS) sc .2 ml/day for 5 days. 2 groups of 8 animals each received 2.5 mg cyproterone acetate twice daily for either 15 or 30 days. 16 animals served as intact controls and 12 animals served as castrate controls. Epididymis and vas deferens sperm counts were not affected by LHAS for 5 days or by cyproterone acetate for 15 days; however, sperm counts were decreased in the corpus (p less than .02), cauda (p less than .05), epididymidis and vas deferens (p less than .01) when rats were treated with cyproterone acetate for 30 days. Castration resulted in a marked reduction in all regions within 5 days. In the intact rats spermatozoa sialic acid decreased in the cauda epididymidis (p less than .01) and increased in the vas deferens (p less than .001). Sialic acid concentration was similar in those treated with either LHAS or cyproterone acetate for 30 days. Bound sialic acid in the epididymal fluid increased (p less than .02) to a maximum in the corpus and cauda and decreased in the vas deferens (p less than .05). LHAS or cyproterone acetate caused a reduction in bound sialic acid in the fluid of the epididymis and vas deferens.     

Immunolocalization of NBC3 and NHE3 in the rat epididymis: colocalization of NBC3 and the vacuolar H+-ATPase

In the male reproductive tract, the epididymis plays an important role in mediating transepithelial bicarbonate transport and luminal acidification. In the proximal vas deferens, a significant component of luminal acidification is Na+-independent, and mediated by specific cells that possess apical vacuolar proton pumps. In contrast, luminal acidification in the cauda epididymidis is an Na+-dependent process. The specific apical Na+-dependent H+/base transport process(es) responsible for luminal acidification have not been identified. A potential clue as to the identity of these apical Na+-dependent H+/base transporter(s) is provided by similarities between the transport properties of the epididymis and the mammalian nephron. Specifically, the H+/base transport properties of caput epididymidis resemble the mammalian renal proximal tubule, whereas the distal epididymis and vas deferens have characteristics in common with renal collecting duct intercalated cells. Given the known expression of the Na+/H+ antiporter, NHE3, in the proximal tubule, and of the electroneutral sodium bicarbonate cotransporter, NBC3, in renal intercalated cells, we determined the localization of NHE3 and NBC3 in various regions of rat epididymis. NBC3 was highly expressed on the apical membrane of apical (narrow) cells in caput epididymidis, and light (clear) cells in corpus and cauda epididymidis. The number of cells expressing apical NBC3 was highest in cauda epididymidis. The localization of NBC3 in the epididymis was identical to the vacuolar H+-ATPase. The results indicate that colocalization of NBC3 and the vacuolar H+-ATPase is not restricted to kidney intercalated cells. Moreover, the close association of the two transporters appears to be a more generalized phenomenon in cells that express high levels of vacuolar H+-ATPase. Unlike NBC3, NHE3 was most highly expressed on the apical membrane of all epithelial cells in caput epididymidis, with less expression in the corpus, and no expression in the cauda. These results suggest that apical NBC3 and NHE3 potentially play an important role in mediating luminal H+/base transport in epididymis.     

Regulation of rat caput epididymidis contractility by prostaglandins

Mechanical activity of the rat caput epididymidis in vitro was recorded using a videomicrography system. The effects of prostaglandin (PG)F2 alpha, PGE2, and aspirin on caput epididymidis contractility were determined by measuring the frequency of contraction, luminal diameter, and amplitude of contraction at various concentrations of each test compound in vitro. PGF2 alpha stimulated contractility of the tubules at physiological concentrations, while PGE2 reduced contractility. Aspirin strongly inhibited contractility at concentrations of 10(-3) and 10(-2)M. Endogenous levels of PGF2 alpha and PGE were determined for rat testes, caput, corpus, and cauda epididymidis and vas deferens. While the concentrations of PGE were consistently higher than those of PGF2 alpha, both compounds were relatively low in the testes, high in the vas deferens, and intermediate throughout the epididymis. Results from these experiments strongly suggest that PGs are important regulators of proximal epididymidis contractions and thus may regulate sperm transport through that organ.     

Effect of adrenalectomy on rat epididymidis

Aim:To investigate the effect of adrenalectomy (ADX) on the epididymidis of Sprague-Dawley rats.Methods:The histological,biochemical(cholesterol protein,zinc,copper,alkaline and acid phosphatase aryl sulphatase,lactic dehydrogenase and leucine amino peptidase)and hormonal (FSH,LH and testosterone) changes of caput and cauda epididymis in ADX rats were observed.Results:Organ wet weight,histological studies and morphometric measurements indicated a cellular degeneration in caput and cauda epididymis of ADX rats.Serum testosterone level was significantly lower in ADX than in sham-operated rats,while the serum FSH and LH were below the detection limit of 1 mIU/mL.The enzymatic activity was higher in ADX than in sham-operated rats.Epididymal zinc level increased whereas copper level decreased in ADX rats compared to the sham-operated.Conclusion:Adrenalectomy leads to degeneration of caput and cauda epididymidis epithelial cells as a result of decreased supply of testosterone.     

Analysis of spermatozoa from the proximal vas deferens of fertile men

Fluids from the left and right proximal vas deferens were collected from 105 normal fertile men by cannulating the vas deferens during vasectomy, and sperm parameters analysed. Sperm motility (73.1 k 13.3Y0), normal sperm morphology (75.2 k 11.1"/o), sperm viability (72.7 k 18.8%) and the hypo-osmotic swelling test (73.3 k 19.2%) were in the normal range, compared with that of ejaculated spermatozoa. However, sperm Concentration in the proximal vas deferens (6274.6 k 5103.8 × 10" ml^-' was higher than that in semen. Sperm concentration in the right vas deferens was significantly higher (P<0.05) than that in the left and the percentage of spermatozoa showing abnormal cervical mucus penetration was Significantly higher (47%) for the left than for the right (18%). There were no anti-sperm antibodies on the surface of spermatozoa from the vas deferens as determined by the sperm cervical mucus contact test and immuno bead test. These parameters of spermatozoa from the proximal vas may reflect those of spermatozoa from the human cauda epididymis.     

Effect of adrenalectomy on rat epididymidis

Aim: To investigate the effect of adrenalectomy (ADX) on the epididymidis of Sprague-Dawley rats. Methods: The histological, biochemical (cholesterol protein, zinc, copper, alkaline and acid phosphatase aryl sulphatase, lactic dehydrogenase and leucine amino peptidase) and hormonal (FSH, LH and testosterone) changes of caput and cauda epididymis in ADX rats were observed. Results: Organ wet weight, histological studies and morphometric measurements indicated a cellular degeneration in caput and cauda epididymis of ADX rats. Serum testosterone level was significantly lower in ADX than in sham-operated rats, while the serum FSH and LH were below the detection limit of 1 mIU/mL. The enzymatic activity was higher in ADX than in sham-operated rats. Epididymal zinc level increased whereas copper level decreased in ADX rats compared to the sham-operated. Conclusion: Adrenalectomy leads to degeneration of caput and cauda epididymidis epithelial cells as a result of decreased supply of testosterone. (Asian J And     

Experimental chlamydial epididymitis

Male Wistar rats were infected with the chlamydial agent of guinea pig inclusion conjunctivitis by inoculation of chlamydiae into the vas deferens. Epididymitis was observed in all infected animals clinically and histologically. Chlamydiae were detected in the epithelium of epididymal tubules by immunohistochemical staining (alkaline phosphatase anti-alkaline phosphatase technique). Inflammation progressed from the cauda to the corpus and caput epididymidis leading to fibrosis of the cauda epididymidis 28 days after infection. Animals responded to the infection with a rise of both serum IgM and IgG antibodies.     

Analysis of spermatozoa from the proximal vas deferens of vasectomized men

This study assessed the condition of spermatozoa from the proximal vas deferens of men after vasectomy. The fluids of both proximal vas deferens were collected from 67 vasectomized men by cannulating the vas deferens at the time of vasectomy reversal. Selected sperm parameters were analysed after incubation of the spermatozoa for 30 min at 37°C. Spera concentration in the proximal vas from vasectomized men (16 312 ± 21 496 million per ml, geometric mean: 7948 ± 398 million per ml) was significantly higher than that of fertile men and was maintained at a constant level independent of the duration of vas obstruction. The means of sperm motility (36.2 ± 26.2%), spermatozoa with normal morphology (50.7 ± 21.7%), sperm viability (53.0 ± 25.3%) and hypo-osmotic swelling test (HOS-test, 53.9 ± 21.7%) were statistically lower than the respective values for normal fertile men. There was no significant correlation between the duration of vas obstruction and the above semen parameters. In 46.4% of vas fluids all spermatozoa were immotile and this condition was more common after 3 years of vasectomy. Immotile spermatozoa in the proximal vas fluids at the time of vasectomy reversal may be an important factor for predicting semen quality and fertilizing ability after vasovasostomy. There were no significant differences in the results of sperm-cervical mucus penetration test (CMPT) between spermatozoa fiom vasectomized and fertile men. Antisperm antibodies on the surface of spermatozoa from the vas of vasectomized men were determined by the immunobead test (IBT; 78.6% for IgG, 32.1% for IgA) and sperm cervical mucus contact test (SCMC, 36.4%). The presence of antisperm antibodies on the spermatozoa from the vas of vasectomized men may explain, in part, the lower pregnancy rate after vasovasostomy. These parameters of spermatozoa from the proximal vas of vasectomized men may closely reflect those in the cauda epididymis after vasectomy.     

The Presence of an Androgen Controlled Phospholipase A in Rat Epididymis

The presence of a phospholipase A (EC 3.1.1.4) and a lysophospholipase (EC 3.1.1.5) has been demonstrated in a postmitochondrial preparation from rat epididymis. Three different enzyme assays using both endogenous and exogenous substrates were employed. Phospholipase A was the rate limiting enzyme in the hydrolysis of lecithin to sn -3-glycerophosphorylcholine which also was the main product of the hydrolysis. The enzyme preparation did not show any phospholipase D (EC 3.1.4.4) nor glycerophosphinicocholine glycerophosphohydrolase (EC 3.1.4.2) activity. A small amount of phosphorylcholine was liberated during the hydrolysis indicating the presence of a glycerophosphinicocholine cholinephosphohydrolase (EC 3.1.4.38).
The phospholipase A activity per mg of protein was 10 times higher in the cauda than in the caput epididymidis, while the corpus epididymidis possessed an intermediate specific activity. Castration reduced the specific activity of the enzyme with about 50% in the caput and with about 95% in the cauda epididymidis. Testosterone supplementation restored the enzyme activity nearly to normal in the castrated animals.
This work suggests that the androgen control of the epididymal concen tration of sn-3-glycerophosphorylcholine is exerted via a control of the phospholipase A activity in the epididymal epithelial cells. It is suggested that this enzyme controls the concentration of epididymal glycerophosphorylcholine and the supply of long chain fatty acids to epididymal spermatozoa.     

Glutathione peroxidase activity in cell cultures from different regions of human epididymis

AIM: To study the secretory activity and androgen regulation of glutathione peroxidase (GPx) in epithelial cell cultures from human epididymis. METHODS: Tissue was obtained from patients undergoing therapeutic orchidectomy for prostatic cancer. Epithelial cell cultures were obtained from the caput, corpus and cauda epididymides. Enzymatic activity was measured in conditioned media by colorimetric methods in absence or presence of 1, 10 or 100 nmol/L testosterone. The effect of 1 micromol/L flutamide was also evaluated. RESULTS: GPx activity was higher in cultures from corpus and cauda than caput epididymidis. The presence of different concentrations of testosterone increase enzyme activity in cell cultures from all epididymal regions. Addition of flutamide reverses the androgen dependent increase of GPx activity. CONCLUSION: GPx activity is secreted from human epididymal cells in a region dependent manner and is regulated by androgens.     

On the Transportation of Spermatozoa in the Vas Deferens

In this report the intraluminal pressure of the vas deferens was measured in vivo in male cross-bred dogs. The measurement of the pressure elucidated that the vas deferens repeated autonomic contraction. This contraction was not the so-called peristalsis but the entire portion of the vas deferens contracted simultaneously. Stimulation of the hypogastric nerves resulted in a prominent elevation of the pressure in the proximal portion of the vas deferens, i.e., the portion approximate to the epididymis, followed 5-10 seconds later by a rise in the distal portion, i.e., the portion approximate to the prostate. These results suggest that the spermatozoa present near the proximal end of the vas deferens are transported littly by little by the autonomic movements of the vas deferens and that on ejaculation the spermatozoa are pressed forward from the proximal end of the vas deferens to its peripheral end by the stimuli through the hypogastric nerves.     

Phosphorus-31 and proton NMR analysis of reproductive organs of male rats

Phorphorus NMR spectra of the whole reproductive organs of male rats and their perchloric acid extracts indicate the presence of phosphocholine and phosphoethanolamine in the testis, glycerophosphocholine (GPC) and glycerophosphoethanolamine (GPE) in the epididymis, and creatine phosphate, GPC, and GPE in the seminal vesicles. High amounts of carnitine and inositol were observed by the proton NMR of perchloric acid extract of the corpus and cauda epididymis. Smaller amounts of these compounds were observed in the caput epididymis and vas deferens; they were totally absent in the testis. Creatine is present in high concentrations in the testis, vas deferens, and seminal vesicles. It is almost absent in all parts of the epididymis.     

Testosterone and dihydrotestosterone levels in the epididymis, vas deferens and preputial gland of mice during sexual maturation

The levels of testosterone (T) and dihydrotestosterone (DHT) in the epididymis, vas deferens and preputial gland were assessed in mice from 1 to 90 days. The weight increase of these 3 organs was proportionately greater than that of the whole body until 50 or 60 days, and they attained their adult histological appearance approximately 20 days prior to puberty. Expressed in ng/g, the concentration of androgens (T+DHT) in the epididymis (14.3 to 36.5), vas deferens (6.6 to 24.0) and preputial gland (1.5 to 4.7) were higher than in plasma (0.2 to 3.6 ng/ml). The concentration of either androgen varied little during sexual maturation and was not correlated with circulating levels. The highest concentration of androgen (T+DHT) was observed at birth suggesting that the neonatal period is crucial for development of the accessory sexual organs. In the epididymis and preputial gland T was the predominant androgen during the infantile phase of development, whilst DHT predominated thereafter. In the vas deferens concentrations of T were always equal to or higher than those of DHT. These results suggest that the ability of the accessory sexual organs to accumulate androgens appears to be more important than the circulating concentration of androgens in determining their growth and differentiation.     

Tissue Specificity of the Epididymal Androgen Dependent Phospholipase A

The effect of androgens on phospholipase A in the rat epididymis, liver, heart, kidney, prostate and epididymal fat pad has been investigated both in the cytosol and in a postmitochondrial partiulate cell fraction.
In both cell fractions, phospholipase A activity was 10–15 times higher in the cauda epididymidis than in the other organs, including the caput epididymidis, while the corpus showed an intermediate activity. In the cauda and corpus, castration reduced phospholipase A activity in both subcellular fractions to the same level as found in the other organs, and testosterone supplementation restored the enzyme activity. No evidence of a similar androgen controlled phospholipase A was found in any other tissue examined, including the prostate.