In vitro Metabolism of (3H)-Androstenedione in the Rat Epididymis and Vas Deferens

The in vitro metabolism of (3H)-androstenedione in the epididymis and vas deferens of intact and castrated rats was investigated and the metabolites formed were identified by radio gas chromatography. Incubation of slices of caput epididymidis for 2 hr at 34 degrees C metabolised 90% androstenedione. Similar incubations of tissue samples from cauda epididymidis and vas deferens metabolized 60 and 25% of androstenedione respectively. The major metabolites formed in the epididymis were androstanedione (caput: 48%; cauda: 33%) and androsterone (caput: 35%; cauda: 13%). These metabolites appeared in much less concentration in the incubations with vas deferens (about 8% each). In general, conversion to testosterone and dihydrotesterone was low in all the three organs examined. Castration did not significantly alter the metabolic pattern in the caput epididymidis and vas deferens but promoted the formation of androsterone (38%) in the cauda epididymidis. The conversion of androstenedione, a weak androgen to testosterone, dihydrotestosterone and 3 alpha/3 beta-diols in the epididymidis and vas deferens of castrated rats may be of physiological significance. In addition, androsterone appears to be an important androgenic metabolite in the epididymis.     

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.     

Interrelationships between androgens and prostaglandins in the vas deferens of prepubertal rats.

Prostaglandin (PG) levels in the genital tract of male rats were measured at different ages. The vas deferens contained the highest amounts of both PGE2 and PGF2 alpha in young adult or prepubertal animals. PGE2 content increased considerably with age. PGE2 alpha was high in younger animals but decreased markedly at 35 days of age and remained low thereafter. PGE2 and PGF2 alpha were reduced following bilateral castration or hypophysectomy. Testosterone propionate (TP) prevented the postoperative fall in PG levels in a dose-dependent manner. Differences were noted in the relationship between changes in organ weight or PGE2 and pge2 alpha content, and the dose of TP injected, the operation, the time of treatment, and the PG studied.     

Effects of the antidepressant St. John's wort (Hypericum perforatum) on rat and human vas deferens contractility

PURPOSE: Since sexual dysfunction related to vas deferens smooth muscle contractility is a possible side effect of St. John's wort (SJW) (Hypericum perforatum) we evaluated the effect of this herbal antidepressant on rat and human vas deferens contractility. MATERIALS AND METHODS: The effect of SJW was evaluated on contractions induced by electrical field stimulation or exogenous agonists (alpha,beta-methylene adenosine triphosphate and phenylephrine) in isolated rat and human vas deferens. RESULTS: SJW (1 to 300 microM) decreased in a concentration dependent manner the amplitude of electrical field stimulation and agonist induced contractions with the same potency, suggesting direct inhibition of rat vas deferens smooth muscle. Of the chemical constituents of SJW tested hyperforin but not hypericin or the flavonoids quercitrin, rutin and kaempferol inhibited phenylephrine induced contractions. SJW and hyperforin also inhibited phenylephrine induced contractions in human vas deferens CONCLUSIONS: The results of our study demonstrate that SJW directly inhibits rat and human vas deferens contractility. If confirmed in vivo, these results suggest that SJW might affect sexual function in humans. These results might explain delayed ejaculation described in patients receiving SJW.     

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.     

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

BACKGROUND: To investigate whether saw palmetto that inhibits alpha1-adrenoceptor binding in vitro affects contractility of the rat prostate gland. METHODS: The effects of a commercially available saw palmetto extract were examined on the contractility of rat-isolated prostate glands. The extract was tested in the presence and absence of phentolamine, prazosin, yohimbine, propranolol, hexamethonium, cocaine, desipramine, nifedipine, guanethidine, atropine, and alpha,beta-methylene ATP to evaluate the mechanism of action. Isolated preparations of rat vas deferens and bladder were used for comparison. RESULTS: Unexpectedly, saw palmetto extract caused contractions of the rat prostate gland that could be attenuated by prazosin, phentolamine, nifedipine, guanethidine, cocaine, and desipramine but not by any of the other pharmacological tools. Similar contractile effects were observed in rat-isolated vas deferens preparations but not in rat-isolated bladder preparations. CONCLUSIONS: In the rat prostate gland, saw palmetto extract causes indirect alpha1-adrenoceptor-mediated contractions via the release of noradrenaline from sympathetic neurons.     

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.     

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.     

Long-term use of sertraline leads to alterations in contractility of rat isolated vas deferens

Previous experiments with rat isolated vas deferens have shown that sertraline pretreatment inhibits contractile responses to noradrenaline, KCl, serotonin and electrical field stimulation. In the present study, the aim was to investigate the effects of long-term use of sertraline on contractile responses of rat isolated vas deferens. Fifteen Sprague-Dawley rats were given long-term (21 days) sertraline treatment, while another 15 were used as control. Both vas deferens were excised. Epididymal and prostatic segments of each underwent electrical field and chemical stimulation (noradrenaline, serotonin, acetylcholine, adenosine-triphosphate). Epididymal and prostatic segments had different contraction characteristics. Long-term sertraline treatment inhibited contractile responses of vas deferens segments to electrical field stimulation. The responses to noradrenaline were amplified with a left shift on both segments. Responses to serotonin had only a left shift on epididymal segments, while no contractile responses were observed on prostatic segments of the groups. Long-term treatment with sertraline had peripheral effects on rat vas deferens contractility, and some of the effects may be through mechanisms other than the inhibition of serotonin re-uptake.     

Cell- and region-specific localization of lysosomal and secretory proteins and endocytic receptors in epithelial cells of the cauda epididymidis and vas deferens of the adult rat.

The epithelial cells lining the cauda epididymidis and vas deferens are active in endocytosis and have an abundance of lysosomes and a well-characterized secretory apparatus. However, little is known about the nature of lysosomal proteins contained within lysosomes, the types of receptors on the cell surface, and the types of proteins secreted by these cells. In the present study, cathepsins A, D, B, and sulfated glycoprotein (SGP)-1, well-characterized lysosomal proteins, as well as SGP-2, a secretory protein and low-density lipoprotein receptor-related protein-2 (LRP-2), an endocytic receptor, were immunolocalized at the light-microscopic level within epithelial cells of the cauda epididymidis and vas deferens. Principal cells showed numerous intensely reactive lysosomes for cathepsins A, D, and SGP-1 in all regions of the cauda and vas deferens and for cathepsin B only in the cauda epididymidis. Basal cells were intensely reactive for cathepsin A, unreactive for cathepsins D and B, and weakly reactive for SGP-1 in the cauda region. In the vas deferens, these cells were intensely reactive for cathepsin A and SGP-1 and unreactive for cathepsin B; in the case of cathepsin D, basal cells were weakly reactive in the proximal vas deferens but intensely reactive in the middle and distal vas deferens. Clear cells, present in the cauda region and proximal vas deferens, were intensely reactive for cathepsin A, weakly reactive for SGP-1, and unreactive for cathepsins D and B, while narrow cells found mainly in the proximal vas deferens were intensely reactive for cathepsins A, D, and SGP-1 and unreactive for cathepsin B. Thus, the expression of different lysosomal enzymes in the cauda epididymidis and vas deferens is not only cell- but also region-specific, suggesting differences in the type of substrates internalized by these cells. SGP-2, a secretory protein, showed a checkerboardlike staining pattern in the cytoplasm of principal cells of the cauda epididymidis, while the cytoplasm of all principal cells were intensely reactive in the vas deferens. This type of reaction, as well as staining of sperm, suggests that SGP-2 is secreted into the lumen, where it functions in relation to sperm. The endocytic receptor LRP-2 was noted only on the apical surface of principal cells of the cauda and vas deferens and in spherical structures indicative of endosomes suggestive of their role in the uptake of various ligands, including SGP-2, for which it has a high binding affinity. Thus SGP-2 in the cauda and vas deferens is not only secreted but endocytosed by principal cells, suggestive of an active turnover in the lumen. In summary, the epithelial cells of the cauda and vas deferens show marked differences in expression of lysosomal proteins, SGP-2, and LRP-2 suggestive of differences in their functional activity while sperm are stored and protected in these regions.     

Differences in the physiological response and ultrastructure of human and guinea pig vas deferens. Effects of prostaglandins, irradiation, and temperature

Marked differences were observed in the mechanical reactions of human and guinea pig vas deferens to prostaglandins, irradiation, and cooling. In human preparations prostaglandin E1 (0.1-1 ng/ml) had an augmentory effect on the contractile response after electrical neurostimulation (10 Hz, 0.3 ms, 3 s), but no visible influence (at concentrations ranging from 1 ng to 10 micrograms/ml) on the contractile response after electrical muscle stimulation (10 Hz, 40 ms, 3 s). In contrast, in guinea pig preparations (PGE1 (0.1-1 ng/ml) had an inhibitory effect on the contractile response after electrical neurostimulation and an augmentory effect (0.1-1 micrograms/ml) on the contractile response after electrical muscular stimulation. Human vas deferens showed higher radiosensitivity than guinea pig preparations. The neurotransmitters acetylcholine and catecholamines increased the radiosensitivity of guinea pig preparations, but not of human ones. Vas deferens reacted to short-time (15-120 s) cooling with an immediate temporary contraction, at 25 degrees C of short (seconds), at 5 degrees C of long (minutes) duration; after rewarming (5-37 degrees C) a second contraction appeared in guinea pig preparations, but not in human ones. Whereas the contraction to electrical neurostimulation (10 Hz, 0.3 ms, 3 s) was abolished in human preparations by cooling, it was only inhibited in guinea pig vas deferens. Electron microscopy showed differences in the ultrastructure of human and guinea pig vas deferens. Muscle cells were more widely separated in human vas deferens (generally 400 nm or more) than in guinea pig (approximately 100-200 nm), and the intracellular space in human preparations contained more collagen. The axons in human preparations contained predominantly large granular and agranular vesicles, those in guinea pig preparations small granular and agranular vesicles. The possible correlation between the physiological response of human and guinea pig vas deferens and the ultrastructural differences is discussed. The results indicate the possibility that other pharmacophysiological and toxicological phenomena could be essentially different in human and guinea pig material.     

Effect of thyroxine on the contractile responses of the vas deferens to prostaglandin E2

The effects of prostaglandin E2 (PGE2) on the contractile activity of thyroidectomized and thyroxine-treated albino rats were studied in vitro. Thyroidectomy totally inhibited the contractile response of the vas deferens to PGE2. Thyroxine treatment, on the other hand, significantly (P < .001) potentiated the response of vasa deferentia to PGE2, when compared to controls. It is suggested that thyroid hormones play a role in the contractile response of the vas deferens to PGE2.     

The importance of a careful search for intra-abdominal testes in cryptorchidism. Report of a case with failure of urogenital union

A five-year-old boy was operated upon for left-sided cryptorchidism. Failure of uro-genital union was found with the left testis and caput epididymidis intra-abdominally situated, and vas deferens and the rest of the epididymis in the lower part of the inguinal canal. The risk of development of malignancy in an intra-abdominal testis has been calculated to be one in 20. If it is impossible to find a testis in the inguinal canal or just inside the internal ring in a patient with cryptorchidism, the peritoneal cavity therefore must be opened and the abdomen carefully explored. The finding of a blind-ended vas deferens with epididymal tissue in the inguinal canal does not exclude an intra-abdominal testis.     

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.     

Effects of prostaglandins on the isolated human minor calyx

Effects of prostaglandins (PGE1, PGE2, PGF2 alpha, and PGI2) on the isolated human minor calyceal strips were isometrically investigated in vitro. PGE2 and PGF2 alpha, 10(-7) to 10(-6) g/ml, increased the basal tone of spontaneous contractions. PGE1 and PGI2 did not affect the contractions of the isolated human minor calyceal strips. The increases on the basal tone induced by PGE2 and PGF2 alpha were not affected by the pretreatment with atropine, hexamethonium, and phentolamine. Following incubation in a Ca2+-free medium, spontaneous contractions and the responses to PGE2 and PGF2 alpha were abolished. The results suggest that the contractile effects of PGE2 and PGF2 alpha may not be mediated by activation of muscarinic, nicotinic, or alpha-adrenergic receptors and result from a consequent increase of the transmembrane Ca2+ influx.     

The luteolytic action of prostaglandin F2-alpha analogues in guinea pig's ovary

The role of prostaglandin at the level of the female genital system is multiple; they are involved in ovulation, luteolysis, contractility of the tube muscles, contraction of the gravid uterus, dilatation of the cervix. The synthetic analogous of the prostaglandin F2 alpha are utilized in a large area of treatments, for multiple purposes. The study was made on 2 lots with 10 non pregnant female guinea pig: the first lot was the witness lot and didn't receive any substance. The second lot received 100 micrograms/kg/day Isopropyl ester PGF2 alpha. The prostaglandin analogous produces vasodilating effects on the ovary blood vessels and luteolytic effects with the destruction of the ovarian follicles.     

Physiology of the vas deferens

Summary Seminal emission occurs in response to rhythmic contractions of male secondary sex organs, including the vas deferens. Although contraction of the vas is directly due to adrenergic mechanisms, numerous substances modulate the release of norepinephrine from sympathetic pathways. These substances include local endogenous factors and neurotransmitters such as acetylcholine and NPY. Many substances are capable of altering the contractility of the vas deferens by modulating neural transmitter release or the basal tone of this smooth muscle. Because multiple pathways and substrates are capable of affecting its contractility, it is not surprising that drugs and metabolic disorders influence the function of the vas deferens and, ultimately, male fertility.     

Hormonal influence on the neurogenic response of the hamster vas deferens

The effect of castration on in vitro contractility of smooth muscle of the vas deferens and body of the bladder has been studied in the hamster. Castration produced supersensitivity to in vitro electrical stimulation and norepinephrine in the vas deferens, but had no effect on the body of the bladder. Castration also increased the maximum contractile response of the vas deferens to electrical stimulation, norepinephrine, ATP, acetylcholine and histamine. The changes in contractility of smooth muscle of the vas deferens developed slowly and may be explained by specific effects upon adrenergic and purinergic neurotransmission and/or non-specific effects upon smooth muscle cell membranes.     

Age-related changes in contractile force of rabbit detrusor muscle to prostaglandin E1, E2 and F2 alpha

Contractile responses of urinary bladder muscle strips to prostaglandin (PG) E1, E2 and F2 alpha were compared in young and old rabbits. All PGs tested caused an increase in contractile force of urinary bladder muscle strips from young (3 weeks) and old (greater than 2 years) rabbits. The contractile response was most marked with PGE2 at concentrations of 10(-10)-10(-7) M in muscle strips from both young and old rabbits. At a high concentration (10(-5) M), the contractile response was most marked with PGF2 alpha in young rabbit bladder muscle strips, whereas in old rabbit bladder muscle strips the magnitude of the responses to PGE2 and PGF2 alpha were equal at 10(-6) M and both were greater than the response to PGE1. The contractile response to PGE1 was greater in old detrusor than in young detrusor at concentrations greater than or equal to 10(-6) M, whereas the contractile response to PGE2 (10(-7)-10(-5) M) and PGF2 alpha (10(-6)-10(-5) M) were greater in young detrusor than in old detrusor. These data show that rabbit detrusor muscle shows a contractile response to PGE1, E2 and F2 alpha and that the magnitude of these responses vary with age.     

Comparison of the effects of primary prostaglandins on isolated human urinary bladder

The effects of primary prostaglandins (PGs) on the dome and trigone of the human urinary bladder were investigated in vitro. In the dome preparations, PGE1 (10(-9) to 10(-6) gm./ml.) showed a weak contractile effect, while PGE2 (10(-9) to 10(-6) gm./ml.) produced dose-dependent contractions. PGF2 alpha (10(-9) to 10(-6) gm./ml.) induced contractions greater than those induced by PGE1 and PGE2. In the trigone preparations, PGE1 (10(-9) to 10(-6) gm./ml.) had no effect, and PGE2 (10(-9) to 10(-6) gm./ml.) produced only a weak contractile response. PGF2 alpha (10(-9) to 10(-6) gm./ml.) showed a greater contractile potency than PGE2. Contractile responses of both preparations to PGE1, PGE2 and PGF2 alpha were not affected by pretreatments of atropine, hexamethonium and phentolamine. These results suggest that the order of potency of primary PGs to induce contractile responses is PGF2 alpha greater than PGE2 greater than PGE1 in both the dome and the trigone preparations, and that the contractile effects of PGE1, PGE2 and PGF2 alpha may not be mediated by activation of muscarinic, nicotinic or adrenergic alpha-receptors.