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)

Bilateral vasa aplasia is considered an invariable finding in cystic fibrosis, but such patients are rarely seen in male infertility clinics. The improved survival beyond 20 years of age is likely to change this. In a clinical study of a group of male cystics the vasa were absent in 8 of 11 boys and epididymal abnormalities were palpable in the majority. The main cause of infertility appears to be mechanical obstruction. Whether the absence is due to a primary failure of mesonephric duct development or secondary to luminal obstruction and subsequent atrophy is not known.
 ...
PMID:Vasa aplasia and cystic fibrosis. 224 27

Sulfogalactosylglycerolipid (SGG) is the major mammalian male germ cell glycolipid and has been implicated in sperm/egg binding. Mycoplasma pulmonis, a species of Mollicutes, is associated with male infertility in rodents. Purified SGG incubated in the presence of M. pulmonis was enzymatically degraded by both desulfation and deacylation. Desulfation occurred primarily at alkaline pH, and deacylation also increased with increased pH, indicating that these represent novel enzymatic activities. Digestion was facilitated, but not dependent on, the presence of detergent. Rat spermatozoa exposed to M. pulmonis showed a reduction in SGG content which was particularly marked for cauda (mature) spermatozoa. With the aid of tlc overlay binding procedure, intact M. pulmonis were found to bind specifically to sulfated glycolipids and thus SGG may provide the cell membrane receptor for this organism. The topology of mycoplasma binding to rat sperm was consistent with the known topology of sperm SGG. The reduced binding (and subsequent digestion) of caput spermatozoan SGG correlates with the membrane colocalization of SGG and its endogenous binding protein at this stage. Separation of SGG and its binding protein during epididymal sperm maturation appears to facilitate M. pulmonis binding to and digestion of cauda sperm SGG. The binding and degradation of the sperm SGG by M. pulmonis may play a role in the induction of infertility which follows infection with these organisms by interfering in sperm/egg receptor recognition.
 ...
PMID:Male germ cell specific sulfogalactoglycerolipid is recognized and degraded by mycoplasmas associated with male infertility. 229 20

Pyrimethamine's antifertility effects in the male mouse suggest that this agent has potential as a male contraceptive. This dihydrofolate reductase inhibitor was administered to 72 adult male Swiss-Webster mice over a 50-day period at dosages ranging from 10-200 mg/kg/day. During the last 10 days of drug administration, the study mice were exposed to 3 female mice who underwent 2 reproductive cycles. The female mice were examined for gravidity 19 days after the onset of the breeding cycle. Male infertility was dose-dependent, with no pregnancies occurring among the partners of mice who received the maximum dosage of pyrimethamine. Also inversely proportional to dosage were the number and motility of epididymal sperm in the treated mice and mean seminiferous tubule diameter and testicular and epididymal weights. Time course analysis revealed that the drug begins to exert its antifertility effect 33 days after administration and nearly complete infertility is achieved with 50 days, suggesting that pyrimethamine acts on early-midspermatogenesis. All mice returned to normal fertility status 44 days after treatment ended, and epididymal sperm reserves, sperm motility, and testicular and epididymal weights also returned to baseline values within this time period. Of particular interest was the finding that when pyrimethamine was administered to another group of mice for 80 days, infertility was significantly reduced beyond that achieved in 50 days, yet there were no further effects on testicular epididymal function. It would appear that pyrimethamine's mechanism of action is its antifolate action, with the main effect occurring on the testes rather than the epididymis.
 ...
PMID:Pyrimethamine: an approach to the development of a male contraceptive. 230 8

Male English springer spaniel dogs affected with fucosidosis, a lysosomal storage disorder, were found to be infertile while females with the disease reproduced successfully. Ejaculates of semen collected from affected dogs had reduced total sperm output and morphologically abnormal spermatozoa. A high proportion of ejaculated spermatozoa had midpiece droplets, bent tails and poor motility. Severely vacuolated epididymal epithelial cells were observed by light microscopy. Electron microscopic examination revealed membrane-bound vacuoles of variable size containing scanty amounts of granular to fibrillar material in epididymal epithelial cells, smooth muscle, myoid cells and Sertoli cells. Male infertility is believed to result from lysosomal storage of fucosyl-linked substrates in cells of the reproductive system. The extensive lesions in the epididymis may have interfered with maturation and transport of spermatozoa. Also, deficiency of alpha-L-fucosidase activity could have impaired the shedding of cytoplasmic droplets from spermatozoa and altered the surface glycoprotein composition of the sperm during epididymal transit.
 ...
PMID:Reproductive abnormalities in canine fucosidosis. 276 Feb 71

The most important disturbances of male infertility are described in detail. The varicocele is in 30 to 40% the main cause of subfertility. 106 out of 125 patients are operated because of unability to conceive a child. Postoperatively, the results show a significant improvement of the sperm density, total sperm count, sperm morphology and the initial and late forward progression. 26% of the couples were achieve pregnancies. In obstructive azoospermia microsurgical repair is the preferable method. The obstruction, whether developmental or acquired, is most frequently at the epididymal junction. Vasography is performed intraoperative immediately before the planned reconstruction to demonstrate the block. In only 5 of 12 patients microsurgical repair was possible. The other patients had developmental abnormalities or scarring and long-distant obstruction. The diagnostic and therapeutic procedures in erectile impotence are described, 5 patients are operated by implantation of a penile prosthesis. The most important step in prophylaxis of infertility is the treatment of cryptorchidism. The therapy should be closed at the end of the second year of life. The role of testicular autotransplantation in selected cases is discussed. Because of more recent data suggest that a male factor is present in or contribute to as many as 50 per cent of the infertility problems and the urologist has the best training and expertise to examine and to diagnose disorders of the male reproductive tract, he should be at the forefront of treatment of these problems.
 ...
PMID:[Contribution of urology in the interdisciplinary treatment concept of fertility disordered males]. 285 19

To evaluate the usefulness of phosphorus-31 magnetic resonance spectroscopy (31P-MRS) in assessing male infertility, we compared it with conventional semen analysis. Specimens were obtained from otherwise healthy patient groups as follows: group A, 7 fertile control subjects; group B, 12 azoospermic men after vasectomy; and group C, 11 patients presenting for infertility evaluation. Correlations between established semen analysis parameters and the 31P-MRS-derived ratio of glycerylphosphorylcholine to total phosphate (GPC/TP) were investigated. Group A controls had a mean GPC/TC ratio of 0.10 +/- 0.05, which was the same as that of group C. With the exception of significantly lowered motility and normal morphology in group C (p less than 0.001 and 0.05, respectively) semen analysis parameters in these two groups were similar. In contrast, the GPC/TP ratio in group B (0.05 +/- 0.04) was significantly different from the control (p less than 0.05), which appropriately reflected complete vasal occlusion. The results suggest that a significant portion of seminal GPC is derived from epididymal secretion and that 31P-MRS is useful for monitoring the GPC/TP levels when assessing epididymal function and male infertility.
 ...
PMID:Assessment of male infertility: correlation between results of semen analysis and phosphorus-31 magnetic resonance spectroscopy. 291 84

Testicular spermatozoa are functionally immature in that they cannot fertilize ova. It was first demonstrated by Young that spermatozoa undergo certain changes as they migrate through the epididymis. He proposed that spermatozoa ripen during epididymal transit. It is now known that specific maturational changes occur in spermatozoa during epididymal transit which result in their developing the ability to fertilize ova. Concomitant with this functional maturity are changes in spermatozoal morphology, motility, chemistry, permeability, density and metabolism. It is apparent that in some way not understood these changes are necessary for sperm to achieve the ability to complete the fertilization process. When these mechanisms are understood, we may be able to effectively treat conditions such as necrospermia or abnormally low sperm motility. Furthermore, with the development of the hamster-egg penetration test a "new" type of male infertility has become evident in recent years; the inability of otherwise normal sperm to penetrate an ovum. It is during epididymal transit that this ability is normally acquired. Thus, any insight into how sperm attain the capacity to penetrate an ovum could lead to an effective treatment of patients whose sperm do not have this ability. In addition, the epididymis holds significant promise as the site of action for a male contraceptive. Thus, it is the purpose of this review to describe the structure and function of the mammalian epididymis with particular emphasis on the factors regulating sperm maturation.
 ...
PMID:Structure and function of the epididymis. 302 75

The present report focuses on novel animal models of male infertility: genetically defined mice bearing single-gene mutations that induce infertility. The primary goal of our investigations was to identify the reproductive defects in these mutant mice. The phenotypic effects of the gene mutations were deciphered by comparing the mutant mice to their normal siblings. Initially testicular steroidogenesis and spermatogenesis were investigated. The physiologic markers for testicular steroidogenesis were steroid secretion by testes perifused in vitro, seminal vesicle weight, and Leydig cell histology. Spermatogenesis was evaluated by the enumeration of homogenization-resistant sperm/spermatids in testes and by morphometric analyses of germ cells in the seminiferous epithelium. If testicular function appeared normal, we investigated the sexual behavior of the mice. The parameters of male sexual behavior that were quantified included mount patency, mount frequency, intromission latency, thrusts per intromission, ejaculation latency, and ejaculation duration. Females of pairs breeding under normal circumstances were monitored for the presence of vaginal plugs and pregnancies. The patency of the ejaculatory process was determined by quantifying sperm in the female reproductive tract after sexual behavior tests. Sperm function was studied by quantitatively determining sperm motility during videomicroscopic observation. Also, the ability of epididymal sperm to function within the uterine environment was analyzed by determining sperm capacity to initiate pregnancy after artificial insemination. Together, the experimental results permitted the grouping of the gene mutations into three general categories. We propose that the same biological markers used in the reported studies can be implemented in the assessment of the impact that environmental toxins may have on male reproduction.
 ...
PMID:Animal models of physiologic markers of male reproduction: genetically defined infertile mice. 331 49

Experimental and clinical data reported in the literature emphasize the important role that immune factors may play in the genesis of male infertility even if many problems still remain to be solved. Auto or homo-sensitization in animals (and in male volunteers) can be obtained with testicular homogenate or epididymal spermatozoa and complete Freund's adjuvant. Immune orchitis in spontaneous human pathology has also been reported. Vasectomy for the voluntary control of male fertility may be considered a particular form of experimental autoimmunization; and many vasectomized individuals develop antisperm antibodies in blood serum and/or in seminal plasma. In spontaneous male infertility antisperm antibodies can: (i) be a mere epiphenomenon; (ii) be a factor aggravating a pathologic situation already able to cause infertility; (iii) play a pathogenetic role in some forms of so-called idiopathic infertility and so could be defined as infertility due to antisperm antibodies. If the antisperm autoimmune reaction represents the casual factor of infertility, corticosteroid therapy seems to give the most satisfactory results, administered either in high doses for a very short time period or in low doses over a prolonged period, or even after transient pharmacologically induced azoospermia.
 ...
PMID:Immunobiology of male infertility. 335 Sep 39

Four patients with persistent oligospermia and necrospermia were found to have severely degenerated sperm in the ejaculate. However, in those examined, testicular sperm were ultrastructurally normal, indicating that sperm degeneration and death was occurring during epididymal passage or storage or both or upon mixing with the seminal plasma at ejaculation. Seminal plasma was found to be nontoxic to normal donor sperm. In three patients, frequent ejaculation (two ejaculates per day for 4 or 5 days) was used to deplete epididymal sperm reserves and reduce the period spent in the epididymis. This resulted in a threefold to sevenfold increase in percentage of motile sperm in the ejaculate and a similar increase in sperm motility index. The authors propose the term "epididymal necrospermia" to describe this previously undefined type of male infertility.
 ...
PMID:Human male infertility caused by degeneration and death of sperm in the epididymis. 337 83


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