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

Mammalian sperm at ejaculation are suspended in the seminal plasma, a heterogeneous mixture deriving from the testicular/epididymal fluid and from secretions of seminal vesicles, prostate and bulbourethral glands. Biochemical characteristics of seminal fluid change along the male reproductive tract when considering its inorganic and organic composition and pH but it is known that in each region of the male genital tract seminal osmolarity is higher than that of serum. It has been previously demonstrated that in invertebrate and vertebrate sperm, seminal plasma osmolarity influences sperm motility and activity, and human sperm have been shown to possess osmosensitive calcium entry pathway that controls important functions such as acrosome reaction and oocyte penetration. In the present study, we have determined seminal plasma osmolarity in a large number of normozoospermic fertile and asthenozoospermic infertile subjects correlating it with sperm motility percentages and kinematic characteristics determined utilizing a computerized motion analysis system. Our results confirm that seminal plasma osmolarity is higher than that of serum (336.1 +/- 20.2 vs. 291.1 +/- 6.9 mOsm/L, respectively). Normozoospermic subjects show seminal osmolarity values that are significantly lower with respect to asthenozoospermic patients (317.8 +/- 12.2 vs. 345.2 +/- 22.6 mOsm/L, p<0.001), irrespective of the cause of asthenozoospermia. Seminal plasma osmolarity negatively correlates with sperm progressive motility percentages and kinetic characteristics (curvilinear velocity, linear velocity, linear coefficient and lateral displacements of sperm head). Furthermore, when sperm from fertile subjects were suspended in medium with an osmolarity increasing from 300 to 600 mOsm, sperm motility percentages and kinetics characteristics were progressively reduced and nearly abolished when medium osmolarity was 600 mOsm. On the contrary, when sperm from asthenozoospermic subjects with high semen osmolarity were resuspended in medium with lower osmolarity, sperm motility parameters improved significantly. Sperm motility parameters did not correlate with seminal plasma concentrations of sodium, potassium, chloride with a weak correlation only with seminal calcium concentration. No correlations are present between seminal plasma osmolarity and ionic composition. In conclusion, the present study confirms and extends the knowledge that, in human, seminal plasma osmolarity is higher than that of serum and demonstrates that seminal osmolarity influences sperm motility characteristics and then it may contribute to the pathogenesis of some forms of asthenozoospermia and male infertility.
 ...
PMID:Role of seminal osmolarity in the reduction of human sperm motility. 1218 Apr 13

Sexually transmitted diseases (STDs) affect the physiology of male/female reproduction. Chronic bacterial infection of semen is uncommon, but may be a cause of male infertility. Antibacterial treatment results in improvement in sperm quality, once the infection is eradicated. Little is known about how infection with Mycoplasma hominis affects semen quality, but treatment with antibiotics improves motility and decreases the percentage of coiled tails. Chlamydia trachomatis is not frequently isolated from the urethral cultures of normal men, but is a major cause of nongonococcal urethritis and epididymitis. Chlamydia is an important cause of epididymal and oviductal obstruction. Trichomonas vaginalis most frequently colonizes the vagina and cervix of women and the anterior urethra of the male sexual partners. The highest prevalence is in sexually active men and women and Trichomoniasis may well be the most common STD. Syphilis may be an important cofactor in facilitating transmission of the human immunodeficiency virus (HIV). A history of syphilis or a positive serologic test for syphilis is associated with HIV seropositivity in men. In South Africa, the seropositivity in pregnant black women ranges from 11-20%. Ga-Rankuwa Hospital is the referral center for 40 peripheral hospitals and over 4 million people. Since the inception of the Andrology Laboratory in June 1985, more than 5300 semen analyses have been performed on 2000 patients.
 ...
PMID:Sexually transmitted diseases (STD) in infertile males attending the andrology clinic at Ga-Rankuwa Hospital. 1228 85

The authors carried out a retrospective study of 162 cases of male infertility explored in a hospital unit in Lyon, France. Assays of 1 -alpha-1,4-glucosidase (epididymal function marker) backed up by clinical findings were used to select 3 types of epididymal malfunction. 1) There was complete obliteration of the epididymal duct, resulting in azoospermia. This diagnosis was based on both testicular biopsy findings, demonstrating unimpaired spermatogenesis and on the dramatically reduced level of assayed activity ( 40 mIU/ejaculation), as well as on clinical findings. 2) There was anamalous epididymal function combined with moderate oligoasthenozoospermia or normospermia. In these cases, low levels of assayed activity do not parallel fairly high sperm counts (between 20-30 million spermatozoal/ml). 3) There were those cases which were difficult to interpret and which involved severe oligoasthenozoospermia ( 5 million/ml) and reduced level of epididymal marker, suggesting partial blockage of the epididymis due to a focus of infection. Varicoceles were found more frequently among the European population, whereas a history of genital infection was more frequent among the North African population. However, when the various types of abnormality in the spermatogram were related to patient history and epididymal abnormality, no differences were found between the 2 populations. (author's modified)
 ...
PMID:[Comparative study of epididymal disorders in two populations of male patients consulting for infertility: one from the Maghreb region of North Africa and the other of European origin]. 1231 60

More and more study on the epididymal function and sperm maturation has shown that epididymis will be one of the best target organs of male contraception, although at present there is not a male contraceptive medicine based on epididymis for clinical practice. The promoting research aspects in epididymal contraception in animal included affecting directly epididymis (such as Sulpasalazine), interfering energy metabolism and sperm mobility (such as Chlorinated Glycerol), altering the internal environment of epididymis (such as copper particles and TW19). The epididymal specific proteins could bring out some new target antigens for immunological contraception, to produce contraceptive vaccine. Some special genes, which expressed distinctively in epididymis such as SC342, bin1, have been cloned and studied on their function. These works would be helpful not only for clinical diagnosis and treatment of epididymitis and male infertility, but also for male contraceptive research and progress.
 ...
PMID:[Study on the male contraceptive based on epididymis]. 1247 33

During epididymal transit, mammalian spermatozoa acquire new surface proteins that are necessary for gamete interaction. P34H, a member of the short-chain dehydrogenase/reductase(SDR) superfamily, is acquired on the acrosomal cap of human spermatozoon during its maturation arising within epididymis. P34H has been shown to be involved in sperm-zona pellucida interaction. Research revealed that the occurrence of low concentration of sperm protein P34H were significant amongst the idiopathic infertile male population and P34H protein could also be considered as a marker of epididymal sperm maturation in human. Therefore the level of sperm protein P34H is proposed to be a auxiliary diagnostic tool for male infertility. This paper reviews the molecular properties and regulation of the expression of P34H and its association with male reproduction.
 ...
PMID:[Epididymal sperm protein P34H and male reproduction]. 1247 27

Infertility affects 13-18% of couples and growing evidence from clinical and epidemiological studies suggests an increasing incidence of male reproductive problems. The pathogenesis of male infertility can be reflected by defective spermatogenesis due to pituitary disorders, testicular cancer, germ cell aplasia, varicocele and environmental factors or to defective sperm transport due to congenital abnormalities or immunological and neurogenic factors. Recent studies suggest an increased incidence of genetic disorders related to male infertility which may affect different levels, interfering with germ cell generation and maturation or leading to the production of non-functional spermatozoa. The identification of genetic causes of male infertility raises the issue of the transmission of defects to the offspring, a situation that is becoming more important given the increasing use of intracytoplasmic sperm injection (ICSI), a procedure in which the natural selection of the spermatozoa is by-passed. Fertilization can occur in vitro using ejaculated, epididymal or testicular spermatozoa, either fresh or frozen-thawed, providing opportunities hitherto not possible for men to be genetic fathers.
 ...
PMID:Male infertility. 1275 96

Spermatozoan maturation, motility, and fertility are, in part, dependent upon the progressive increase in epididymal and spermatozoal carnitine, critical for mitochondrial fatty acid oxidation, as sperm pass from the caput to the cauda of the epididymis. We demonstrate that the organic cation/carnitine transporters, OCTN1, OCTN2, and OCTN3, are expressed in sperm as three distinct proteins with an expected molecular mass of 63 kDa, using Western blot analysis and our transporter-specific antibodies. Carnitine uptake studies in normal control human sperm samples further support the presence of high-affinity (OCTN2) carnitine uptake (K(m) of 3.39+/-1.16 microM; V(max) of 0.23+/-0.14 pmol/min/mg sperm protein; and mean+/-SD; n=12), intermediate-affinity (OCTN3) carnitine uptake (K(m) of 25.9+/-14.7 microM; V(max) of 1.49+/-1.03 pmol/min/mg protein; n=26), and low-affinity (OCTN1) carnitine uptake (K(m) of 412.6+/-191 microM; V(max) of 32.7+/-20.5 pmol/min/mg protein; n=18). Identification of individuals with defective sperm carnitine transport may provide potentially treatable etiologies of male infertility, responsive to L-carnitine supplementation.
 ...
PMID:Characterization of organic cation/carnitine transporter family in human sperm. 1278 76

Cyclosporine A (CsA) is known to have testicular toxicity, leading to male infertility. The occurrence of numerous anomalous spermatids and residual bodies in the epididymal ducts of rats treated with CsA was observed in our previous studies. To examine the fine structural changes of impaired spermiogenesis induced by CsA, rats were treated s.c. with 40 mg/kg/day CsA for 2 weeks. Desquamation of round spermatids still surrounded by a slender Sertoli cell cytoplasm was occasionally observed. A prominent change in the seminiferous tubules was an occurrence of numerous residual bodies containing one or more flagella. They were not phagocytosed by the Sertoli cell, and accumulated in the epididymal ducts. Cellular components in the epididymal lumen included degenerating round spermatids and abnormal spermatozoa and residual bodies. Although separation of the head from the tail of the spermatozoa was rarely seen, various kinds of abnormalities of flagella were frequently encountered; compact aggregation of numerous flagella in a single spermatozoon or residual body, disarrangement of mitochondrial or fibrous sheath with outer dense fibers, and fusion of flagella with a single intervening mitochondrial layer. These findings indicate that CsA gives rise to toxic effects on the spermiogenesis by impairing directly the spermiogenic cell development and by impeding Sertoli cell function including a reduction of its phagocytic activity.
 ...
PMID:Ultrastructural study on cytotoxic effects of cyclosporine A in spermiogenesis in rats. 1450 63

A history of urogenital inflammation occurs in 5-12% of men attending infertility clinics. Usually, infection has a detrimental effect on sperm quality by reducing concentration and motility, and possibly affecting the number of morphological normal spermatozoa. In addition, infection may be the source of auto-antibodies against spermatozoa, found in about 8% of the infertile male population. In contrast to the situation in women, there is no clear evidence that male accessory gland infections can result in epididymal blockage or vassal obstruction, with the exception of genital tuberculosis. Although Chlamydia trachomatis is a well-documented source of chronic prostatitis, the infection does not seem to cause obstruction of the reproductive tract, as it does in women. If male urogenital infection causes obstruction it is most likely located at the level of the ejaculatory ducts. Chronic prostatitis has been proved to cause scarring of the prostatic and ejaculatory ducts, resulting in low seminal volume with low fructose and alpha-glucosidase. Many of these men present with severe oligozoospermia or azoospermia, normal size testis and normal gonadotrophins. We performed an excisional testicular biopsy in all men presenting with <1 million spermatozoa per millilitre and found that 39 of 78 (50%) had a normal spermatogenesis. A history of male accessory genital infection was found in 12% of the men and 10% had abnormalities found on transrectal ultrasound of the prostate (like oedema, dilatation of the seminal vesicles and ejaculatory ducts) intraprostatic calcifications and dilatation of the periprostatic venous plexus. Ejaculatory duct obstruction is a common cause of male infertility and infections are present in at least 22-50% of these men. Transurethral resection of the ejaculatory ducts may result in a significant improvement of the sperm quality and in spontaneous pregnancies in up to 25% of the couples. In case of failure sperm aspiration from the epididymis and intracytoplasmic sperm injection is the treatment of choice.
 ...
PMID:Inflammatory-associated obstructions of the male reproductive tract. 1453 64

Traditional gene knock-out approaches using homologous recombination in embryonic stem cells are routinely used to provide functional information about genes involved in reproduction. In the present study, we examined a novel approach using N-ethyl-N-nitrosourea (ENU) together with a balancer chromosome mating strategy to identify new loci with functional roles in male fertility. Our genetic strategy is a forward-genetic approach; thus, our phenotypic investigation begins with the discovery of an abnormal phenotype without previous knowledge of the mutant locus. We isolated eight recessive mutations on chromosome 11 that resulted in male or female infertility from a screen of 184 founder pedigrees from ENU-treated males. After testing the six male infertile and two female infertile mutations for their ability to complement, we found that three independent recessive male infertile mutations failed to complement each other. The male infertility was associated with reduced epididymal sperm count, a block in late-spermatid differentiation, and increased apoptosis. Furthermore, the three male infertile mutants had severe defects in epididymal sperm morphology associated with incorrect microtubule assembly. Electron microscopy revealed unique defects in sperm head and tail morphology for each of the three alleles. One allele had an abnormal manchette assembly of the sperm head. The other two alleles had different abnormalities in the 9+2 patterning of the microtubules in the sperm tail axoneme, with one containing only five of the microtubule doublets and the other containing an extra doublet. The isolation of this allelic series identifies a new locus on mouse chromosome 11 that is required for spermiogenesis and male fertility.
 ...
PMID:Mutations in a novel locus on mouse chromosome 11 resulting in male infertility associated with defects in microtubule assembly and sperm tail function. 1471 86


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>