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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Secretion of electrolytes and water by the epididymal epithelium is important in the formation of an optimal fluid environment for sperm maturation and storage. Recently, evidence has been obtained that anion/fluid secretion by the epididymis is subject to control by local humoral factors, among which the angiotensins play a significant role. This assertion is based on the morphological localization of various components of a local renin-angiotensin system (RAS) in the rat epididymis and the functional studies of angiotensins and their antagonists on anion secretion in cultured rat epididymal epithelia. More recent study has indicated that the effects of angiotensin II and other vasoactive peptides on anion secretion are mediated through an increase in prostaglandin formation. The pathway of synthesis involves the PLA2-coupled receptor mediated breakdown of membrane phospholipids to arachidonic acid followed by conversion of arachidonic acid into the prostanoids by cyclooxygenases and other enzymes. The newly formed PGE2 then diffuses out of the cells and acts on the EP2/4 receptors on the same or adjacent cells to increase intracellular cAMP. Accordingly, the pathways of activation by the paracrine factors all converge on the cystic fibrosis transmembrane conductance regulator (CFTR) as the final common effector in secretion. Studies on the biochemical pathways of paracrine control of fluid secretion may provide insight into the causes of epididymal irregularities in some forms of male infertility.
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PMID:The role of local angiotensins and prostaglandins in the control of anion secretion by the rat epididymis. 1064 62

Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are a relatively frequent cause of male infertility. Depending on their molecular consequences, CFTR mutations may either result in typical cystic fibrosis (CF), one of the most common autosomal recessive disorders, which is characterized by chronic lung disease, pancreatic exocrine insufficiency, an increase in the concentration of sweat electrolytes and male infertility, due to obstructive azoospermia, or in atypical (often monosymptomatic) forms of CF such as congenital absence of the vas deferens (bi- or unilateral), bilateral ejaculatory duct obstruction or bilateral obstructions within the epididymides. All males with idiopathic obstructive azoospermia bear an increased risk for CF offspring. Couples requesting microsurgical epididymal sperm aspiration and in vitro fertilization, e.g. intracytoplasmic sperm injection, should be offered genetic counselling and molecular genetic analysis of the CFTR gene, if male infertility due to obstructive azoospermia is the underlying cause.
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PMID:CFTR gene mutations and male infertility. 1075 89

The widespread application of intracytoplasmic sperm injection (ICSI) has raised concern about the efficacy and safety of this novel technique. The European Society of Human Reproduction and Embryology (ESHRE) has established an ICSI Task Force to collect annually the clinical results, the outcome of pregnancy, and the follow-up of children after ICSI using ejaculated, epididymal, and testicular sperm in order to address these important issues in a relatively short time. Over a 3-year span (1993-1995), the number of centers for ICSI increased from 35 to 101, and the total number of ICSI cycles per year rose from 3,157 to 23,932. The incidence of oocytes damaged by the procedure remained low (< 10%), whereas the fertilization rates obtained with ejaculated, epididymal, and testicular spermatozoa for 1995 were 64%, 62%, and 52%, respectively. Thus, 86-90% of the couples had embryo transfer, and the viable pregnancy rate was 21% for ejaculated, 22% for epididymal, and 19% for testicular sperm, while the incidence of multiple gestations was 29%, 30%, and 38%, respectively. It is noteworthy that no difference was found in ICSI results concerning the etiology of azoospermia, for example, obstructive (congenital or acquired) or nonobstructive. Furthermore, 3,149 transfers of frozen-thawed embryos after ICSI with ejaculated, epididymal, or testicular sperm were performed, and in 11%, 9%, and 7% of them, respectively, a viable pregnancy was achieved. The ICSI results were similar during this 3-year period, irrespective of the origin of the sperm. The perinatal outcome of children born after ICSI was not different from that after in vitro fertilization or natural conception and was only affected by multiplicity. Moreover, the incidence of major or minor malformations was not increased, but the chromosomal, especially the sex chromosomal, aberration rate was slightly elevated (approximately 2%). Therefore, ICSI has opened new horizons in the treatment of male infertility. The achievement of pregnancy after ICSI using ejaculated, epididymal, or testicular sperm is very satisfactory. The procedure seems to be safe, but further follow-up of the children is necessary to more accurately assess its safety.
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PMID:Intracytoplasmic sperm injection. Survey of world results. 1081 22

Complete bilateral ejaculatory duct obstruction has long been recognized as an uncommon, treatable form of male infertility. Partial ejaculatory duct obstruction reflects a disturbance of ejaculation where sperm quality is impaired during transit through the distal vas deferens and ejaculatory ducts. With the advent and increased use of high-resolution transrectal ultrasonography, abnormalities of the distal ejaculatory ducts related to infertility have been well documented. Although there are no pathognomonic findings associated with ejaculatory duct obstruction, several clinical findings are highly suggestive. In an infertile man with oligospermia or azoospermia with low ejaculate volume, normal secondary sexual characteristics, testes and hormonal profile and dilated seminal vesicles, midline cyst, or calcification on transrectal ultrasonography, ejaculatory duct obstruction is suggested. Of course, other causes of infertility may be concomitantly present and need to be searched for and treated as well. In selected cases, transurethral resection has resulted in marked improvement in semen parameters and pregnancies have been achieved. As is the case with all surgical procedures, proper patient selection and surgical experience are necessary to obtain optimal results. However, it appears that the treatments currently available for relief of ejaculatory obstruction are not optimally effective. Only approximately one half of treated patients will have an improvement in semen parameters and only about one quarter of treated patients will contribute to a pregnancy. What remains to be determined is how to manage the additional nearly 50% of patients who do not benefit from transurethral resection of ejaculatory obstruction. Based on my experience, I suggest that transrectal ultrasonography should be the first diagnostic procedure used when infertile men are suspected of having ejaculatory duct obstruction; however, vasography should still be considered for a more comprehensive diagnosis of ejaculatory duct obstruction. In patients showing atrophic seminal vesicles on transrectal ultrasonography and having a history of pulmonary tuberculosis, further study is not necessary and microscopic epididymal sperm aspiration is recommended for in vitro fertilization. Qualitative measurement of semen fructose may be helpful in the diagnosis of partial ejaculatory duct obstruction. Patients having midline cyst and being treated by transurethral resection are expected to have the best outcome.
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PMID:Transurethral resection of the ejaculatory duct. 1083 Aug 18

It has been over two decades since the birth of the first child conceived by in vitro fertilization (IVF). During the intervening years, technology has evolved; however, IVF has not solved the problems concerning sperm. The first successful pregnancies after the intracytoplasmic injection of a single spermatozoon into an oocyte (ICSI) were rapidly followed by the widespread use of this novel technique for the treatment of male factor infertility. Injection of motile (living) spermatozoa into the oocyte is the most important factor in obtaining good results and other sperm parameters, anti-sperm antibodies and sperm origin, i.e., ejaculated, epididymal and testicular, do not have a strong influence on the outcome of ICSI. ICSI has revolutionized the treatment of male infertility and the application of ICSI is rapidly expanding around the world. However, this technique avoids the natural process of sperm selection and fertilization. Therefore, it is of utmost importance to monitor carefully the development, throughout childhood and into adulthood, of individuals born as a result of ICSI in order to assess its safety. ICSI should only be used for specific indications until its safety has been established. In this paper, the current status of two new approaches, ICSI with spermatid and donor oocyte cytoplasm transfusion, is also reviewed.
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PMID:[The current status of assisted reproductive technology]. 1101 79

Recent advances in human cryobiology have been substantially greater than the first slow step from freezing spermatozoa in animals in Italy, published in 1776 to observing motility in frozen-thawed human sperm in 1938(1). Reports on cryopreservation of rabbit oocytes (1947)(1) and births from fertilised frozen-thawed mice oocytes in 1977(1) were soon followed by the first human pregnancy (1983)(1) and birth (1984)1 following transfer of frozen-thawed embryos after in-vitro fertilisation (IVF). Whereas cryopreservation of human sperm and embryos in tertiary level fertility centres is now commonplace, the full clinical, scientific and sociological consequences of progress in this rapidly moving field are to be determined. These include pregnancy with frozen-thawed human mature, oocytes after conventional IVF (1986)4, intracytoplasmic sperm injection (ICSI)(5) (1996), pregnancies following use of frozen-thawed mature (1995)(5,6) and immature oocytes (1999)(7), ovarian tissue banking (8) and possible autografting (1999)(9) as well as repeated freeze-thawing of male gametes and of embryos (10,11). Cryopreservation of female and male gametes instead of embryos offer solutions of obvious religious, ethical, legal and clinical problems. In addition, there may be benefits in reducing the cost of infertility treatment, improving the safety of fertility treatment with respect to ovarian hyperstimulation syndrome and repeated treatment with controlled ovarian hyperstimulation, prevention of diseases such as sexually transmitted diseases and hereditary disorders and preventing infertility by possible long-term storage of gametes, gonadal tissue and even embryos. The benefits of cryopreservation of sperm, oocytes and embryos in the management of subfertile couples, many being self-evident to some, bear emphasis. Cryopreservation of sperm offers substantial organisational, cost and social advantages in IVF/ICSI treatment, in that it is no longer necessary for both partners to be present at the time of oocyte retrieval, or to have the sperm retrieval done simultaneously, as frozen-thawed sperm (ejaculatory, epididymal or testicular) can be used. This strategy permits men in the latter two categories to be able to support their partners at the time of oocyte retrieval, with the knowledge that their sperm surgically obtained some time previously, is available. It is now clear that, in men with obstructive azoospermia, the use of fresh or frozen-thawed sperm will yield equivalent fertilisation rates following ICSI. In men with non-obstructive azoospermia, with a 60% chance only of obtaining sperm from the testicular aspiration or biopsy, the option could be cryopreservation of the sperm harvested first and later controlled ovarian hyperstimulation of the female partner, to use thawed sperm which will lead to equivalent fertilisation rates using fresh sperm. Thus, one may avoid cost of treatment of the female in those couples who do not wish to use donor sperm as a back-up in the 40% of men from whom sperm is not obtained. Important consequences of cryopreservation of gametes and gonadal tissue are likely to be in the area of prevention of hereditary and familial diseases, as cryopreservation of oocytes, sperm, embryos and blastocysts is exploited fully in pre-implantation genetic diagnosis (PGD) strategies12. Embryo biopsy now permits screening to identify normal embryos from couples who are carriers of known single gene defects and hereditary disorders and the list of these conditions is expanding rapidly. PGD is feasible on frozen-thawed blastomeres even if cells have lysed after thawing, providing information relevant for surviving blastomeres or blastocysts. But what of the gene probes which will soon deluge us on the completion of the Human Genome Project? Can we anticipate benefits and consider proposing that couples with familial disorders, whether degenerative e.g. Type 2 Diabetes, or malignant conditions such as cancer of the ovary, breast and colon? Should we cryopreserve oocytes/sperm/embryos for the purposes of PGD once the markers are available? Cryobiology indeed provides hope now for women and men with neoplastic diseases, who are about to receive oncotherapy for malignancies which inevitably will render them sterile. Men may now freeze epididymal, testicular as well as ejaculatory sperm as ICSI has revolutionalised the treatment of male infertility. It might be likely that testicular tissue from prepubertal boys can be cryopreserved with a reasonable expectation that techniques will soon be developed to effect maturation of spermatogonia in-vivo or in-vitro13. The greatest advance is likely to be for women suffering from reproductive cancer, who may now consider mature and immature oocytes being frozen or vitrified with a reasonable chance of fertilisation by ICSI later, as well as the cryopreservation and storage of ovarian cortex tissue biopsies. Work is proceeding still to refine techniques of in-vitro maturation of frozen-thawed immature oocytes, and the frozen-thawed ovarian cortex tissue slices. The potential benefits will not only be to female fertility for the latter conditions but endocrine disorders as well as by autotransplantation (1999)9. Currently, ovarian tissue banking8 is being considered by women undergoing procedures or treatment which could destroy ovarian function with quite realistic but cautious expectations of preserving ovarian function, but tomorrow women may consider banking ovarian tissue as insurance against childlessness because of the risk of disorders in the reproductive tract (endometriosis, simple recurrent ovarian cysts) and even advancing years. For those who have conceived with surplus oocytes cryopreserved, anonymous oocyte donation is a possibility for the solution of ethical and legal problems. All over Europe, the age of women having their first child is dramatically increasing now being in their late twenties, with likely significant implications in the need to fertility treatment in the Millennium. Society has always been excited but understandably cautious about the prospect of whole body cryopreservation. Hippocrates would have argued that Society could separate medicine and its advances from religious views, dogma and prejudice and, on the present evidence, would probably have looked upon human cryobiology favourably. Human cryobiology is here to stay and society as well as the profession is addressing its relevance. There are clear signs that this technology can and will alleviate suffering by preventing genetic and familial diseases, infections and infertility as well as lowering the cost and social consequences of the treatment. For these reasons, further research in this field should be welcomed and supported.
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PMID:Cryobiology in human assisted reproductive technology. Would Hippocrates approve? 1175 34

There have not been many studies concerning CFTR gene alterations in nonobstructive causes of male infertility and subfertility, and in those that have been published, the results reported are not concordant. Therefore, we proposed to determine, in a representative unselected sample of men who were sent for microsurgical epididymal sperm aspiration, if different types of male infertility and impaired fertility were associated with CFTR gene alterations. We screened 80 men with idiopathic azoospermia, 50 men with severe oligozoospermia, 70 men with oligoasthenoteratozoospermia, and 7 men with congenital bilateral absence of the vas deferens (CBAVD), as well as 95 controls from Slovenia, for mutations in 10 CFTR exons that include the majority of the most common cystic fibrosis (CF) disease causing mutations. We also wanted to evaluate the risk for CF in children born after the intracytoplasmic sperm injection (ICSI) method of in vitro fertilization (IVF). No tested individual had mutations in both CFTR alleles. Altogether 13 different nucleotide alterations were identified. The frequencies of both CFTR gene alterations and polymorphisms did not differ significantly between the control group and men with idiopathic nonobstructive azoospermia and subfertility, but were significantly increased in men with CBAVD (DeltaF508, p = 0.039; IVS8-5T, p = 0.006). Our results suggest that CFTR mutations are not associated with errors in spermatogenesis and nonobstructive pathology of urogenital tract in men with any frequency. However, genetic counseling and CFTR mutation screening continue to be recommended for men with obstructive azoospermic conditions and their female partners.
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PMID:Involvement of CFTR gene alterations in obstructive and nonobstructive infertility in men. 1178 91

It is well established that congenital hypothyroidism leads to male infertility. However, there is a dearth of information on foetal-onset hypothyroidism-induced changes in the epididymis. With regard to transient hypothyroidism, the existing literature deals mainly with the testis. However, it is not known whether there is any corresponding alteration in epididymal morphology and physiology under such a condition. The present study is therefore aimed at understanding the impact of persistent and transient hypothyroidism on the concentration of epididymal sex steroids, as they play a vital role in maintaining the normal structure and function of the epididymis. Normal rats of 90 days of age served as controls (Group I). Hypothyroidism was induced by using pregnant/lactating mothers and post-weaning rats to 0.05% (w/v) methimazole (MMI) in the drinking water. Group II were subjected to persistent hypothyroidism from day 9 of post-coitum (pc) to 90 days. Group III rats were subjected to transient hypothyroidism from day 9 day pc to day 1 post-partum (pp), 21 pp or 35 pp (IIIa, b and c, respectively) and group IV rats were given simultaneous T3 supplementation (3 microg/100 g body wt./day i.m.) with MMI from day 9 pc to day 1 pp; 21 pp and 35 pp (Group IVa, b and c). Animals from all groups were killed on day 90 pp. Serum thyroid stimulating hormone (TSH) and thyroid hormones confirmed euthyroidism in group I, IIIa, b and c and IVa, b and c rats and hypothyroidism in group II rats. Caput and cauda epididymal concentration of testosterone, dihydrotestosterone (DHT), estradiol (E2) and androgen binding protein (ABP) markedly decreased in group II rats. While the concentration of testosterone, E2 and ABP increased in group III rats, that of DHT remained unaltered. However, group IV rats maintained normal concentration of the sex steroid and ABP. The activity of 5-alpha-reductase in the epididymis of all the groups followed the same trend as that of the concentration of epididymal DHT. From the present data it is evident that persistent hypothyroidism diminishes the bioavailability of androgens and oestrogens, while transient hypothyroidism enhances the same, indicating the importance of euthyroidism during foetal and neonatal period towards the maintenance of optimal hormonal status in the epididymis required for its maturation.
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PMID:Impact of foetal-onset hypothyroidism on the epididymis of mature rats. 1203 Oct 41

Approaches to study human epididymal functions are limited. Therefore, suitable animal models are highly desirable, yet difficult to find among the few species studied on a molecular level to date. This review summarizes our progress in the development of the canine epididymis as an alternative model. Dogs are biomedically a key species because they are subject to many of the same diseases as humans and already serve as a model for a number of human pathologies, including genetic diseases. It is thus consistent that an appraisal of epididymal specific gene expression has been started in the dog, including the molecular cloning and characterization of canine epididymal proteins. These proteins, in addition to a high overall sequence similarity to the human, show a similar tissue distribution, relative abundance and spatial pattern within the epididymis. Moreover, the dog epididymis offers an excellent source for cell culture studies, and immortalization of the canine epididymal duct epithelium has been achieved, encouraging regulatory studies of epididymal gene expression in vitro. Thus, the dog already fulfils many of the criteria of a good model of the human epididymis on a molecular level. Further progress may be expected with the advance of the canine genome project. If there is a genetic basis for male infertility, then the dog provides the advantage of the exploitation of a species that combines a maximum of genetic variation within a species with the capacity to minimize that variation within a defined pedigree.
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PMID:The dog as a model to study human epididymal function at a molecular level. 1214 99

Results of clinical observations of male infertility cases seen in S eoul, Korea, National University's Department of Urology between January 1955 and December 1969 are presented. 920 infertile men were seen, repr esenting 3.2% of 36,071 urological outpatients, and 3.9% of 30,125 male outpatients seen during this 15-year period. The number of male inferti lity cases has increased from 10 (1.09%) cases in 1955 to 166 (18.04%) cases in 1969. Primary sterility was found in 78% of the 920 infertile cases in 1969. Primary sterility was found in 22%. The ages of the infertile men ranged from 24 to 61 years (mean=35); the ages of their sp ouses ranged from 24 to 49 years (mean=32). Infertile marital life ranged from 1 to 40 years (mean=7). The duration of infertility cases seen between 1955 and 1959 was 10 years, between 1960 and 1964, 8 years; and between 1965 and 1969, 6 years. There was no close correlation between incidence of infertility and occupation (290 cases were white-collar workers and 414 were physical laborers). Etiological classifications indicate that 40% of the male infertility cases were due to faulty spermatogenesis, 21% due to faulty transportation, 14% due to faulty seminal composition, .5% due to faulty ejaculation, and 24% from unknown causes. In 840 cases where semen was analyzed, 51% had azoospermia, 34% had oligospermia, and 7% had normospermia. In 41 cases analysis revealed normal semen, however, no children have been conceived in 3 years. Testicular biopsies of azoospermias revealed 30% hypospermatogenesis, 27% germinal aplasia, 20% germinal cell arrest, 11% efferent duct occlusion, 9% peritubular fibrosis, and 3% normospermatogenesis. There was no significant difference in average frequency of sexual intercourse between fertile and infertile couples. Medical treatment combined with various drugs (e.g., testosterone, vitamedine) for 3-12 months was most effective in oligospermia (52 out of 101 cases) and azoospermia (13 out of 126 cases). In 22 cases of bilateral epididymal obstruction treated by epidiymovasostomy, viable sperm appeared in the ejaculates of 9. Vasovasostomy performed on 85 previously vasectomized men yielded successful results in 62 of 71 azoospermia cases in which the semen could be repeatedly examined.
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PMID:[Studies on male infertility: 6. Clinical observation on male infertility]. 1217 11


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