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

Epididymal sperm reserve was determined in 6 sexually mature fertile buffalo-bulls having normal process of spermatogenesis. The relative distribution of spermatozoa in the caput, corpus and cauda epididymidis averaged 5.42, 0.75 and 11.45 billion respectively. Total epididymal sperm reserve per bull averaged 36.2 billion. In terms of percentage the caput, corpus and cauda epididymidis contained 30.76, 4.25 and 64.99 per cent sperm respectively.
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PMID:Epididymal sperm reserve in Buffalo-bulls (Bubalus bubalis). 73 80

Infertile spermatozoa from the proximal corpus epididymidis will become fertile when this epididymal segment is cultured 24 h in vitro with 5alpha-dihydrotestosterone (5alpha-DHT). The effect of antiandrogens and inhibitors of RNA and protein synthesis upon this 5alpha-DHT-induced sperm maturation was investigated. The response to 5alpha-DHT was abolished by cyproterone acetate, SKF 7690, actinomycin D, cycloheximide, puromycin, and the aminonucleoside analog of puromycin. Addition of cyproterone acetate or actinomycin D to a suspension of distal corpus spermatozoa did not change their fertilizing ability. Culture of segments of the distal corpus for 24 h with the same antiandrogens and RNA and protein synthesis inhibitors did not change the fertilizing ability of spermatozoa. These results indicate that the development of the sperm-fertilizing ability observed in the proximal corpus epididymidis in vitro in response to 5alpha-DHT is dependent upon binding of 5alpha-DHT and synthesis of new RNA and protein molecules by the target cell. They also indicate that antiandrogen and inhibitors of RNA and protein synthesis do not have a nonspecific toxic effect on spermatozoa during the time period studied. It is likely that the target cells are the epididymal epithelial cells rather than the spermatozoa themselves.
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PMID:The maturation of rabbit epididymal spermatozoa in organ culture: inhibition by antiandrogens and inhibitors of ribonucleic acid and protein synthesis. 74 83

Agglomeration of spermatozoa (pseudo-autagglutination, clumping of spermatozoa) is distinguished from agglutination in immunological processes by the coarse meshwork of the spermatozoa clumps and the central inclusion of epithelia, leukocytes, residual bodies, spermatozoa with persisting cytoplasmatic droplets, as well as parts of viscous seminal plasma. In 658 semen samples of out-patients with barried marriage, spermatozoa agglomerations were seen in 13.4% of the samples immediately after liquefaction while in additional 6.7%, they were found up to three hours later. The agglomeration phenomenon is typical but not specific of the so-called vegetative congestion syndrome, appearing concomitant with high spermatozoa counts, normal rate of spermatozoa motility and morphology, as well as an increase in residual bodies and spermatozoa with persisting cytoplasmatic droplets. Next to congestion syndrome, spermatozoa agglomerations may also result from post-inflammatory disturbances of epididymal or accessory gland function whereas in florid stages of inflammation, they are rarely observed. As the congestion syndrome may give rise to male infertility in some cases, andrologists should be acquainted with its clinical and spermatological symptoms with special regard to therapy.
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PMID:[Findings and significance of spermatozoa agglomeration in the semen]. 77

Protein changes in epididymal and ejaculated spermatozoa were studied in bulls treated orally on alternate days with a total of 10 doses (each of 4 mg/kg body weight) of ethylene dibromide. No significant changes were found in the total nitrogen, amino acid or lipoprotein contents of the spermatozoa collected either from the epididymis 1 day after the last dose, or from ejaculates 9-13 days after the end of the treatment. Significant changes were found in the percentage composition of amino acids of the sperm proteins and lipoproteins but the changes differed in the caput, cauda and ejaculated spermatozoa.
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PMID:Changes in total nitrogen, lipoproteins and amino acids in epididymal and ejaculated spermatozoa of bulls treated orally with ethylene dibromide. 77 80

Bovine epididymal spermatozoa incubated aerobically in vitro in the presence of 0.1 to 0.2 mM CaCl2 accumulate 25 to 50 nmol of calcium/10(8) cells. The addition of low concentrations of the ionophore A23187 (0.01 to 0.5 nmol/mg of sperm protein) induces efflux of this accumulated calcium. At high ionophore concentrations (0.5 to 5.0 nmol/mg of sperm protein), calcium release is followed by an influx of up to 25 nmol of calcium/10(8) cells that is not dependent on mitochondrial energization. A selective increase in the permeability of the sperm plasma membrane produced by treatment with the polyene antibiotic, filipin, results in the release of that calcium which is accumulated in the presence of high concentrations of A23187. Sperm first treated with filipin possess the ability to accumulate and retain calcium (in the presence of an oxidizable substrate) but release Ca2+ without subsequent reaccumulation after the addition of 3 nmol of A23187/mg of protein. These observations are explained by the existence of competing calcium pumps operating within the mitochondrial and plasma membranes of the spermatozoan. Treatment with high concentrations of A23187 allows calcium influx into a non-mitochondrial compartment of the sperm cell as a consequence of the equilibration of this cation across both mitochondrial and plasma membranes. The amount of calcium uptake and its sensitivity to filipin indicate that calcium binding to soluble, intracellular components is also involved. The ability of low concentrations of A23187 to induce calcium efflux is explained as a result of the continued operation of the plasma membrane pump coincident with ionophore-induced decay of the concentration gradient across the mitochondrial membrane. This hypothetical action of low levels of the ionophore on the mitochondria is supported by the observation of net movements of calcium with filipin-treated cells and the respiratory responses and movements of phosphate and membrane-associated calcium with intact sperm. It is suggested that the basis of this apparent selectivity of ionophore action lies in the relative activities and kinetic properties of the competing calcium pumps in the plasma and mitochondrial membranes of these cells. Ionophore-induced influx of calcium into the extramitochondrial space results in a stimulation of respiration and kinetic activity of the sperm. This activation of motility is observed also with cells made entirely dependent upon glycolysis (by treatment with respiratory inhibitors) and suggests a direct involvement of calcium in the regulation of flagellar function.
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PMID:Action of ionophore A23187 at the cellular level. Separation of effects at the plasma and mitochondrial membranes. 77 78

The present status and perspectives in the control of fertility in the male have been reviewed. There are two potential sites in the male reproductive processes that can be used as targets for regulation of fertility in the male: (1) inhibition of spermatogenesis, and (2) interference with sperm maturation in the epididymis. A variety of compounds tested for their antispermatogenic action in laboratory animals have no future for the control of fertility in the human male because of a number of undesirable side effects (cf. Prasad, 1973). Progestational compounds inhibit spermatogenesis by affecting the hypothalamo-hypophysial system and result in impairment of libido. The possibility of adjustment of the minimal dose of progestational compounds required to induce suppression of spermatogenesis and reduction of plasma testosterone to a level compatible with the maintenance of normalcy of libido and potency needs to be studied. A new approach to contraception in the male involves the use of a combination of progestational compounds for suppression of spermatogenesis along with testosterone (administered through silastic capsule implants or as intramuscular injections) for maintenance of libido and accessory sex gland function. A number of such combinations have been tested clinically with some success. However, the limitations of side effects, such as weight gain, gynecomastia, and psychological complications preclude their long-term use for contraception in man. Short-term use of these combination regimens by the male for 1 year followed by use of a contraceptive method by the female may be desirable to encourage partnership in family planning. Although testosterone and other androgens suppress spermatogenesis in man, the feasibility of their use for contraception depends on the establishment of a dosage and mode of adminstration that provide antispermatogenic action without causing more general metabolic alterations. Inhibition of spermatogenesis by selective interference with the action of FSH on the Sertoli cells by active or passive immunization or by selective suppression of synthesis and release of FSH by administration of "Inhibin" offers exciting possibilities in the control of fertility in the male. Studies on the physiology of the rete testis highlight its importance as a post-tubular site of action of antifertility agents in conveying (to the epididymis) compounds interfering with epididymal functions and/or viability of spermatozoa. A new approach to the induction of functional sterility in the male by selective alteration of epididymal function by a local androgen deprivation effect has been successfully tested in clinical trials. Small doses of cyproterone acetate, administered orally, result in maintenance of libido and accessory sex gland function accompanied by a decrease in the motility of ejaculated spermatozoa and incomplete inhibition of spermatogenesis...
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PMID:Target sites for suppressing fertility in the male. 79 48

Spermiation and epididymal maturation of spermatozoa were studied in the bonnet monkey (Macaca radiata) by light and scanning electron microscopy. The morphology, location, and release of residual body were observed during spermiation. Along the epididymal duct, the shape of spermatozoa changed, the constriction at the anulus disappeared, the marginal thickening diminished in length, and the cytoplasmic droplet regressed and moved toward the posterior end of the middle piece. Mature spermatozoa were very similar to those of other Cercopithecidae, and they showed a forward motility and a drop in eosin stainability.
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PMID:Spermiation and epididymal maturation of spermatozoa in the bonnet macaque (Macaca radiata) as viewed by scanning electron microscopy. 80 37

The effects of norepinephrine, phentalamine, oxytocin, vasopressin, several prostaglandins, and indomethacin on the spontaneous motility of isolated guinea pig cauda epididymidis were explored. Phentolamine and indomethacin reduced the isometric peak tension of spontaneous epididymal contractions. Phentolamine also depressed the frequency. Both findings suggest that catecholamines and endogenous prostaglandins are in some way regulators of the spontaneous motility of the cauda epididymidis. Norepinephrine resulted in the development of a distinct, sustained, tonic contraction without phasic activity, whereas prostaglandins E1, E2, and F2 alpha elicited a tonic increase accompanied by frequent, superimposed, phasic contractions. Both oxytocin and vasopressin comparably enhanced epididymal motility, producing contractile responses similar to those observed with prostaglandins. Since the epididymal contractions can influence the time spent by spermatozoa in passing through the ductus epididymidis, the above-mentioned compounds could play an important role in spermatozoal transport via modulation of epididymal contractile activity. In addition, such naturally occurring substances might regulate the release of sperm from the last portion of the epididymis into the ductus deferens.
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PMID:Physiologic and pharmacologic studies on the motility of isolated guinea pig cauda epididymidis. 80 41

The motility of spermatozoa from successive segments of human and animal epididymides was examined under the phase-contrast microscope. The segments were taken from laboratory rodents unilaterally vas ligated for three to five months and from human orchiectomy specimens. Evidence for testicular alteration, caused by epididymal stasis proven by the phase-contrast motility profile, was sought by weight, gross observation, and histologic examination. Two observations were made on the animals: (1) the ligature about the vas seldom resulted in epididymal stasis because the ligature cut through the muscular wall of the vas (permitting a leak);and, (2) when stasis was achieved, gross and microscopic alterations of the testis from the normal were inevitable. The observations of the human material showed that a progressive loss of sperm motility during passage through the epididymis occurred in more than one half the specimens. The motility profile of these epididymides closely resembled that seen in the unilaterally vas-ligated animals. The suggestion is made that senescence of a testicle may be caused by occlusion of its excurrent ducts. These observations seemed to support the hypothesis that faulty sperm transport and faulty maturation, becuase of epididymal rupture and fibrosis (rather than the presence of autoantibodies to sperm) probably cause the unreliability of vasovasostomy. Storage of frozen semen offers more certainty than the possibility of successful vasovasostomy.
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PMID:When and why does occlusion of the vas deferens affect the testis? 80 7

Experiments were performed to establish the daily level of testicular production of spermatozoa, the distribution of spermatozoa within the epididymis, and the time required for transport of spermatozoa through the epididymis in 8 sexually rested rhesus monkeys (Macaca mulatta) of at least 6 years of age. The daily production of spermatozoa was similar among all animals, averaging a production rate of 23 times 10 (6) sperm/gm of testicular parenchyma per day. However, the weight of testicular parenchyma ranged from 15 to 32 gm. Per testis , the average daily spermatozoal production was found to be 547 plus or minus 69 tomes 10(6). Consequently, the normal average production of spermatozda for the rhesus monkey per day during the breeding seasson is about 1.1 times 10(9). The number of sperm in the caput, corpus, and cauda epididymis was found to be .6 plus or minus .1, 2.1 plus or minus .3, and 2.9 plus or minus .3 times 10(9), respectively. 1 plus or minus .1 times 10(9) sperm were found in the proximal 49-70 mm of the ductus deferens. The mean transport times of sperm through the caput, corpus, and cauda epididymis were approximately 1.1, 3.8, and 5.6 days, respectively. The rate of transport of sperm through the epididymis was virtually the same between 2-5.5 days, even though a 265-fold difference in epididymal reserves was found. The results indicate that sperm matures within the epididymis of this species within 5 days.
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PMID:Daily spermatozoal production, epididymal spermatozoal reserves and transit time of spermatozoa through the epididymis of the rhesus monkey. 82 87


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