Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This review summarizes the introduction of ICSI in the early 1990s as an assisted fertilization procedure in couples with severe male factor infertility, who could not be helped by conventional IVF. As for current practice, the indications for ICSI using fresh or frozen-thawed ejaculated, epididymal or testicular sperm are reviewed as well as some reports on the use of ICSI in non-male infertility. The main steps in an ICSI cycle are well standardized by now; it is rare that ICSI cannot be carried out and the results in terms of fertilization, embryo transfer and clinical pregnancy rate have been consistent for many years, indicating that a substantial number of couples can now have their own genetic child instead of having to use artificial insemination with donor sperm. This review also emphasizes the importance of assessing the risk of ICSI for the children: there is a slight increase in de novo chromosomal abnormalities, the major congenital malformation rate is similar for IVF and ICSI (between 3 and 4%), and at approximately 2 years of age the developmental outcome as assessed by the Bayley scale is similar for IVF and ICSI. Recent publications mention that a few children are affected by diseases caused by imprinting disorders. Future studies are needed to assess the association between assisted reproductive technologies and imprinting disorders. ICSI is frequently used in couples undergoing preimplantation genetic diagnosis. PGD stricto sensu as well as PGD for aneuploidy screening and for Klinefelter patients are reviewed using the ESHRE PGD Consortium data.
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PMID:A review of ten years experience of ICSI. 1500 61

Transgenic mice with male infertility, the c-ros knockout (KO) and GPX5-Tag2 transgenic mouse models, are compared. Both exhibit severely angulated sperm flagella explaining the infertility. As angulated spermatozoa are swollen cells, a failure in volume regulation is indicated. Differences between genotypes were also found: caudal spermatozoa from c-ros KO, but not GPX5-Tag2, could fertilise eggs in vitro; flagellar angulation occurred more within the epididymis of GPX5-Tag2 than c-ros KO mice; the osmotic pressure of cauda epididymidal fluid was lower only in GPX5-Tag2 mice; angulation of caudal sperm from c-ros KO, but not GPX5-Tag2 mice, decreased upon demembranation. These observations indicate that GPX5-Tag2 mice express an earlier, more severe defect. Gene chip analyses of the epididymides revealed decreased expression of the CRES (cystatin-related epididymal-spermatogenic) and MEP17 (murine epididymal protein 17) genes in both genotypes. Further analysis could pinpoint genes essential for epididymal regulation of sperm volume, explain infertility and suggest modes of male contraception.
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PMID:Mouse models of infertility due to swollen spermatozoa. 1510 45

Reactive oxygen species (ROS) play a role in male infertility, where excessive amounts impair spermatozoal motility. Epididymal antioxidant enzymes protect spermatozoa from oxidative damage in the epididymal lumen. Antioxidant secretions from the seminal vesicle protect spermatozoa after ejaculation. As it is known that with age there is increased generation of ROS, the goals of this study were to determine how aging affects the response of antioxidant enzymes in the epididymis, seminal vesicles, and liver to l-buthionine-S,R-sulfoximine (BSO) mediated glutathione (GSH) depletion, and to examine the impact of GSH depletion on motility parameters of spermatozoa from the cauda epididymidis in young (4-mo-old) and old (21-mo-old) rats. Levels of GSH and glutathione disulfide (GSSG), as well as activities of glutathione peroxidase, glutathione reductase, catalase, and superoxide dismutase, were measured in the caput, corpus and cauda epididymidis, seminal vesicles, and liver. Spermatozoal motility was assessed by computer-assisted sperm analysis. Significant age-related changes in antioxidant enzyme activities were found in the liver and cauda epididymidis. Glutathione depletion clearly affected tissues in both young and old. The compounding effect of age was most evident in the cauda epididymidis, seminal vesicles, and liver, where antioxidant enzyme activities changed significantly. Additionally, spermatozoa motility was adversely affected after BSO treatment in both age groups, but significantly more so in older animals. In summary, the male reproductive tissues and liver undergo age-related changes in antioxidant enzyme activities and in their response to GSH depletion.
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PMID:Effect of glutathione depletion on antioxidant enzymes in the epididymis, seminal vesicles, and liver and on spermatozoa motility in the aging brown Norway rat. 1515 30

In mouse, two different isoforms of ADAM1 (fertilin alpha), ADAM1a and ADAM1b, are produced in the testis. ADAM1a is localized within the endoplasmic reticulum of testicular germ cells, whereas epididymal sperm contain only ADAM1b on the plasma membrane. In this study, we show that the loss of ADAM1a results in the male infertility because of the severely impaired ability of sperm to migrate from the uterus into the oviduct through the uterotubal junction. However, epididymal sperm of ADAM1a-deficient mice were capable of fertilizing cumulus-intact, zona pellucida-intact eggs in vitro despite the delayed dispersal of cumulus cells and the reduced adhesion/binding to the zona pellucida. Among testis (sperm)-specific proteins examined, only the level of ADAM3 (cyritestin) was strongly reduced in ADAM1a-deficient mouse sperm. Moreover, the appearance of ADAM3 on the sperm surface was dependent on the formation of a fertilin protein complex between ADAM1a and ADAM2 (fertilin beta) in testicular germ cells, although no direct interaction between the fertilin complex and ADAM3 was found. These results suggest that ADAM1a/ADAM2 fertilin may be implicated in the selective transport of specific sperm proteins including ADAM3 from the endoplasmic reticulum of testicular germ cells onto the cell surface. These proteins then can participate in sperm migration into the oviduct, the dispersal of cumulus cells, and sperm binding to the zona pellucida.
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PMID:Possible function of the ADAM1a/ADAM2 Fertilin complex in the appearance of ADAM3 on the sperm surface. 1519 97

Advantage of using a vaccine based on sperm antigens is that it can be used both in males and females as individuals who have antisperm antibodies are usually infertile but otherwise healthy. Several sperm specific antigens identified as prospective candidates for immunocontraception are of testicular origin. For the purpose of immunocontraception it may be desirable not to disrupt spermatogenesis and testicular function. Concept of post testicular maturation of spermatozoa has been very well established. During post testicular voyage spermatozoa undergo a series of complex and sequential events which transforms the immature immotile spermatozoa into mature sperm. Acquisition of functional maturity is necessary for progressive motility, zona pellucida recognition culminating in sperm egg binding. Importance of epididymal maturation is highlighted by the fact that high percentage of male infertility in human originates from the malfunction of the epididymis. The epididymis has also shown to be involved in sperm storage and provides an adequate environment for final maturation of the sperm. It provides a conducive microenvironment by virtue of which the spermatozoa are protected during the storage. In view of this it is imperative that more attention needs to be focused on epididymal antigens. The information obtained will enable us to identify epididymal antigens relevant to fertility and also help in infertility diagnosis.
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PMID:Epididymis as a target for contraception. 1525 79

In the past 5 to 10 years, very few fields in modern medicine have changed so dramatically as reproductive medicine, especially for the treatment of male infertility. Advances have been made in intracytoplasmic sperm injection (ICSI), refined microsurgical reconstructive techniques (vasovasostomy and vasoepididymostomy), and microsurgical techniques of surgical sperm retrieval from the epididymis and testis. All men with epididymal obstruction (obstructive azoospermia) now have the opportunity to father their own biological children. In this article, the authors reviewed the most updated microsurgical vasovasostomy, vasoepididymostomy techniques and surgical indications as well as the key factors for successful microsurgical treatment. They also predicted the future directions and discussed the advantages of microsurgical techniques, emphasized the significant roles of microsurgical training for urological doctors to treat male infertility.
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PMID:[Microsurgical approaches to the treatment of obstructive azoospermia]. 1549 74

Oxidative stress has been shown to be a major cause of male infertility; a large proportion of infertile men have elevated levels of seminal reactive oxygen species (ROS). High concentrations of ROS cause sperm pathology such as ATP depletion leading to insufficient axonemal phosphorylation, lipid peroxidation and loss of motility and viability. L-carnitine, a naturally occurring enzymatic antioxidant, is a necessary factor in the utilization of long chain fatty acids to produce energy. Furthermore, it plays a pivotal role in the maturation of spermatozoa within the male reproductive tract. Epididymal plasma contains the highest levels of L-carnitine found in the human body, and initiation of sperm motility occurs in parallel to L-carnitine increase in the epididymal lumen. It is known that L-carnitine prevents the formation of ROS, scavenges free radicals and protects cells from peroxidative stress. Moreover, it plays a key role in sperm metabolism by providing readily available energy for use by spermatozoa, which positively affects sperm motility, maturation and the spermatogenic process. L-carnitine and its derivatives have been proposed recently for treatment of male infertility, and a number of controlled and uncontrolled human and animal studies have been conducted to indicate their possible application. As a result, antioxidant therapy with carnitines may represent a new nonhormonal option within a broader therapeutic strategy in men with ROS-mediated infertility.
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PMID:Oxidative stress, male infertility and the role of carnitines. 1615 68

Estrogens play an important role in the male reproductive tract, and this is especially so for the efferent ductules, where alpha-estrogen receptors (ERalpha) have been localized. Mice deficient in ERalpha (alphaERKO mice) are infertile, and the effect appears to be due in part to retention of water at the level of the efferent ductules. In the present study, we examined the consequences of ERalpha deletion on the distribution of certain aquaporins (AQPs), water protein channels, in the efferent ductules and on sperm numbers and motility. In addition, the effects of feeding mice a regular lab chow diet, which contains phytoestrogens, known to affect male reproductive tract functions, and a casein diet, which lacks phytoestrogens, were also assessed. Light microscope immunolocalizations of AQP-1 and AQP-9 revealed dramatic reduction and patchier staining in alphaERKO mice with distal areas of the efferent ductules being more affected than proximal areas. No other changes in immunolocalizations were noted as a consequence of diet. Computer-assisted sperm analyses demonstrated a 62% reduction in cauda epididymal sperm/ml in alphaERKO mice fed lab chow, whereas 87% fewer sperm/ml were observed in alphaERKO mice fed casein, suggesting an enhanced role for sperm production and concentration in a diet containing phytoestrogens. All sperm motility parameters were altered to some degree in alphaERKO mice fed lab chow. Alterations in sperm motility parameters were also detected, but were less dramatic in alphaERKO mice fed casein. These data suggest that the decrease in AQP expression in the efferent ductules of alphaERKO mice contributes in part to water retention in this tissue, eventually leading to backflow of water into the testis, with subsequent decreases in sperm concentration and motility. The data also suggest that phytoestrogens, which are present in regular lab chow, can influence the male reproductive tract with and without the presence of ERalpha, promoting efferent ductule and epididymal functions when ERalpha is expressed, but inhibiting these same functions when ERalpha is missing. Taken together the data underscore the importance of estrogens and ERalpha in maintaining sperm maturation and preventing male infertility.
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PMID:Expression of aquaporins in the efferent ductules, sperm counts, and sperm motility in estrogen receptor-alpha deficient mice fed lab chow versus casein. 1626 9

Epididymal defects in infertile domestic species and transgenic mice demonstrate the role of the epididymis in influencing sperm function. Spermatozoa from these males cannot negotiate the female tract as they fail to regulate their volume. The latter is necessary to counter the osmotic stresses encountered in the female tract. Reduced epididymal provision of osmolytes or their premature loss is discussed as probable causes of failed volume regulation. Measuring cell volume regulation for diagnosis of male infertility and blocking it as a means to male contraception are briefly considered. Unchecked human population growth is destroying habitats supporting vulnerable and endangered species. Genome resource banks have been established to preserve spermatozoa of genetically valuable individuals. As cryopreservation stresses spermatozoa osmotically, this process could jeopardise volume regulation with consequences for fertility. Knowledge of sperm volume regulation and the uptake of organic solutes may permit improvement in sperm storage and prevent osmolyte-related cryodamage.
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PMID:Utility of infertile male models for contraception and conservation. 1649 33

Rats were treated with 0, 8, 16 and 24 mg/kg of lead acetate (LA) (i.p.) for 35 days with or without Maca. Maca was co-administrated orally from day 18 to day 35. The lengths of stages of the seminiferous epithelium were assessed by transillumination. Also, sex organ weights, testicular and epididymal sperm count, sperm motility, daily sperm production, sperm transit rate and serum testosterone levels were measured. Lead acetate treatment resulted in a dose-response reduction of lengths of stages VIII and IX-XI, and serum testosterone levels. However, rats treated with 8 and 16 mg/kg but not 24 mg/kg of lead acetate showed a low number of testicular spermatids, low daily sperm production (DSP) and low epididymal sperm count. Administration of Maca to rats treated with lead acetate resulted in higher lengths of stages VIII and IX-XI with respect to lead acetate-treated rats. Moreover, treatment with Maca to lead acetate-treated rats resulted in lengths of stages VIII and IX-XI similar to the control group. Maca administration also reduced the deleterious effect on DSP caused by lead acetate treatment. Maca prevented LA-induced spermatogenic disruption in rats and it may become in a potential treatment of male infertility associated with lead exposure.
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PMID:Lepidium meyenii (Maca) reversed the lead acetate induced -- damage on reproductive function in male rats. 1651 Feb 28


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