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Sperm Function (sperm + function)
Selected AbstractsRole of sperm ,v,3 integrin in mouse fertilizationDEVELOPMENTAL DYNAMICS, Issue 3 2010Céline Chalas Boissonnas Abstract Oocyte integrins have been described as essential for fertilization. But this concept has been challenged by deletion experiments. Recently, we have shown that sperm integrin ,6,1 plays a determinant role in mouse gamete interaction. In this study, we demonstrate the presence of ,v,3 integrin by Western blot and immunofluorescence on the sperm membrane. Oocytes and/or sperm preincubations with anti-,v or anti-,3 antibodies were performed before in vitro fertilization on cumulus-intact and zona-free egg assays. We observed inhibitory effects on the fusion process mostly by means of sperm function. An antibody directed against vitronectin inhibited gametes fusion, whereas the presence of exogenous vitronectin increased its efficiency. We suggest that vitronectin (on multimeric forms) can play a first nonspecific link corresponding to loosely bound spermatozoa to oocyte and that this link could be mediated by means of oocyte proteoglycans or integrins, and sperm ,v,3 integrin. Developmental Dynamics 239:773,783, 2010. © 2010 Wiley-Liss, Inc. [source] Advanced glycation end products accumulate in the reproductive tract of men with diabetesINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 4 2009C. Mallidis Summary Light microscopic studies comparing sperm parameters show little association between diabetes and male fertility. However, with the introduction of new analytical techniques, evidence is now emerging of previously undetectable effects of diabetes on sperm function. Specifically, a recent study has found a significantly higher sperm nuclear DNA fragmentation in diabetic men. As advanced glycation end products (AGEs) are important instigators of oxidative stress and cell dysfunction in numerous diabetic complications, we hypothesized that these compounds could also be present in the male reproductive tract. The presence and localization of the most prominent AGE, carboxymethyl-lysine (CML), in the human testis, epididymis and sperm was determined by immunohistochemistry. Parallel ELISA and Western blot analyses were performed to ascertain the amount of CML in seminal plasma and sperm from 13 diabetic and nine non-diabetic subjects. CML immunoreactivity was found throughout the seminiferous epithelium, the nuclei of spermatogonia and spermatocytes, in the basal and principle cells cytoplasm and nuclei of the caput epididymis and on most sperm tails, mid pieces and all cytoplasmic droplets. The acrosomal cap, especially the equatorial band, was prominently stained in diabetic samples only. The amount of CML was significantly higher (p = 0.004) in sperm from non-diabetic men. Considering the known detrimental actions of AGEs in other organs, the presence, location and quantity of CML, particularly the increased expression found in diabetic men, suggest that these compounds may play a hitherto unrecognized role in male infertility. [source] Sperm function tests and fertilityINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 1 2006R. J. Aitken Summary Traditionally, the diagnosis of male infertility has depended upon a descriptive evaluation of human semen with emphasis on the number of spermatozoa that are present in the ejaculate, their motility and their morphology. The fundamental tenet underlying this approach is that male fertility can be defined by reference to a threshold concentration of motile, morphologically normal spermatozoa that must be exceeded in order to achieve conception. Many independent studies have demonstrated that this fundamental concept is flawed and, in reality, it is not so much the absolute number of spermatozoa that determines fertility, but their functional competence. In the light of this conclusion, a range of in vitro tests have been developed to monitor various aspects of sperm function including their potential for movement, cervical mucus penetration, capacitation, zona recognition, the acrosome reaction and sperm,oocyte fusion. Such functional assays have been found to predict the fertilizing capacity of human spermatozoa in vitro and in vivo with some accuracy. Recent developments in this field include the introduction of tests to assess the degree to which human spermatozoa have suffered oxidative stress as well as the integrity of their nuclear and mitochondrial DNA. Such assessments not only yield information on the fertilizing capacity of human spermatozoa but also their ability to support normal embryonic development. [source] Asthenozoospermia: Possible association with long-term exposure to an anti-epileptic drug of carbamazepineINTERNATIONAL JOURNAL OF UROLOGY, Issue 1 2005TETSUO HAYASHI Abstract Little attention has been paid to infertility in men with epilepsy and little information exists about the mechanisms by which anti-epileptic drugs affect spermatogenesis or sperm function. We report a case of a male infertility patient with asthenozoospermia during long-term treatment with anti-epileptic drugs. A 29-year-old man had continued treatment with anti-epileptic drugs under the diagnosis of epilepsy for 13 years. He and his wife had been examined and treated as an infertile couple for 3 years. The patient was found to have no motile sperm with a normal sperm count, while taking a dose of 400 mg/day of carbamazepine. On suspicion of an adverse effect of carbamazepine, he was switched to phenytoin monotherapy. One month after that, sperm motility was vastly improved (65%) and they conceived a child 5 months after that. One must be cautious in extrapolating from a case report, but these findings strongly suggest a direct effect of carbamazepine on spermatic function. [source] The significance of platelet-activating factor and fertility in the male primate: a reviewJOURNAL OF MEDICAL PRIMATOLOGY, Issue 1 2005William E. Roudebush Abstract:, Since its discovery nearly 30 years ago platelet-activating factor (PAF) has emerged as one of the more important lipid mediators known. PAF (1- O -alkyl-2- O -acetyl- sn -glycero-3-phosphorylcholine) exists endogenously as a mixture of molecular species with structural variants of the alkyl moiety. PAF is a novel potent signaling phospholipid that has unique pleiotropic biological properties in addition to platelet activation. PAF also plays a significant role in reproduction and is present in the sperm of a number of primate species. PAF content in squirrel monkey sperm is significantly higher during the breeding season than the non-breeding season. PAF content in rhesus sperm has a significant relationship with sperm motility. PAF content in human sperm has a positive correlation with seminal parameters and pregnancy outcomes. The enzymes (lyso-PAF-acetyltransferase and PAF-acetylhydrolase) necessary for PAF activation and deactivation are present in primate sperm. PAF-acetylhydrolase may act as a ,decapacitation factor'. Removal of this enzyme during capacitation promotes PAF synthesis increasing primate motility and fertilization. PAF also plays a significant role in the fertilization process, enhancing the fertilization rates of oocytes. Enhanced embryo development has also been reported in oocytes fertilized with PAF-treated sperm. Exogenous PAF will also significantly improve primate artificial insemination pregnancy outcomes. PAF antagonists inhibit sperm motility, acrosome reaction, and fertilization thus suggesting the presence of receptors for PAF. The PAF-receptor is present on primate sperm, with altered transcript levels and distribution patterns on abnormal cells. Whereas, the exact mechanism of PAF in sperm function and reproduction is uncertain, its importance in normal primate fertility is substantial. [source] Synthesis and structure,activity relationship of ,-defensins, multi-functional peptides of the immune systemJOURNAL OF PEPTIDE SCIENCE, Issue 4 2006Enno Klüver Abstract ,-defensins are a large family of multiple disulfide-bonded peptides occurring in mammals and birds. They play an important role in the innate immune system, directly killing microbial organisms. Recent research has demonstrated that ,-defensins are important for other biological functions beyond antimicrobial effects, including inhibition of viral infection, interaction with Toll-like receptors, chemotactic effects, and sperm function. The corresponding broad spectrum of activities makes this peptide class an important subject and tool in immunologic research. In this review, we summarize the current status of the routes to obtain synthetic ,-defensins, their major structural properties and structure,activity relationship. Copyright © 2006 European Peptide Society and John Wiley & Sons, Ltd. [source] Consistent significant variation between individual males in spermatozoal morphometryJOURNAL OF ZOOLOGY, Issue 2 2001Edward H. Morrow Abstract Comparative studies show that variation in sperm morphometry across taxa is associated with the environment in which sperm function, and the species' mating pattern dictating the risk of sperm competition. Accordingly, sperm have evolved to function in a non-self environment (in contrast to somatic cells) and sperm morphometry is predicted to be optimized independently of the individual male producing them, but is the result of selective forces arising directly from the fertilization and competitive environment in which sperm will operate. Males within a population are therefore under stabilizing selection to produce an optimal distribution of sperm sizes. The nature of this distribution was explored using consistent techniques to measure detailed sperm morphometry for 10 species in a range of taxa from insects to humans. Although we expected variance in sperm morphometry to be optimized by every individual male through stabilizing selection at a population or species level, we found the exact opposite; for every species examined there was significant variation between individual males in the total lengths of the sperm they produced. A significant variation is reported between individual males for every species in the sizes of each sperm head, mid-piece and flagellum component. The between-male variation exists consistently in wild, domestic and human populations, subject to a wide range of levels of inbreeding. In gryllid crickets sperm length is shown to be male-specific and is repeatable between successive ejaculates. Between-female variation in ova size (data are presented for trout) is explainable by individual female fecundity optimization strategies; however, the adaptive significance of widespread between-individual variance in male gamete size is counter-intuitive and difficult to interpret, particularly as the limited evidence available shows that sperm morphometry is not condition-dependent or resource-constrained. The differences, however, do suggest negligible influences from haploid expression in the development of sperm morphometry , if haplotypic expression were manifested we would expect more profound variation within a male's sperm population (to reflect the inherent within-male variance in haplotypes derived from recombination) rather than the significant between-male differences we found that suggests the diploid control of spermatozoal phenotype [source] Effect of exogenous DNA on bovine sperm functionality using the sperm mediated gene transfer (SMGT) techniqueMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 8 2010Sebastian Canovas Sperm mediated gene transfer (SMGT) could provide the opportunity to carry out transgenesis on a mass scale using spermatozoa as vectors for exogenous DNA. However, the efficiency of sperm-mediated DNA transfer is still questionable, and the mode of transmission to the egg has not yet been well understood. Our aim was to investigate the capacity of bovine spermatozoa to carry exogenous DNA and its relationship to sperm functionality. We studied these parameters using flow cytometry to measure viability (necrosis and apoptosis) and capacitation status, computer-assisted semen analysis (CASA) to measure motility parameters and in vitro fertilization (IVF) to assess fertilizing capacity. Furthermore, we studied the effect of capacitation status on interaction with exogenous DNA, and the role of heparin supplementation in this process. Bull spermatozoa showed a high capacity to bind DNA quickly and reached a maximum after 30,min, with approximately half of the DNA-bound spermatozoa being viable. Incubation with exogenous DNA induced a decrease in sperm viability and motility and increased the proportion of apoptotic cells, but did not affect the cleavage rate in IVF assay. Heparin increased high-lipid disorder and the number of sperm with DNA bound (viable and dead). In conclusion, this study shows that live spermatozoa can bind exogenous DNA with a slight negative effect in some parameters of sperm function that in our opinion, would not drastically compromise fertility. Mol. Reprod. Dev. 77: 687,698, 2010. © 2010 Wiley-Liss, Inc. [source] Detection and characterization of gamete-specific molecules in Mytilus edulis using selective antibody productionMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 1 2009Heiko Stuckas Abstract The mussel Mytilus edulis can be used as model to study the molecular basis of reproductive isolation because this species maintains its species integrity, despite of hybridizing in zones of contact with the closely related species M. trossulus or M. galloprovincialis. This study uses selective antibody production by means of hybridoma technology to identify molecules which are involved in sperm function of M. edulis. Fragmented sperm were injected into mice and 25 hybridoma cell clones were established to obtain monoclonal antibodies (mAb). Five clones were identified producing mAb targeting molecules putatively involved in sperm function based on enzyme immunoassays, dot and Western blotting as well as immunostaining of tissue sections. Specific localization of these mAb targets on sperm and partly also in somatic tissue suggests that all five antibodies bind to different molecules. The targets of the mAb obtained from clone G26-AG8 were identified using mass spectrometry (nano-LC-ESI-MS/MS) as M6 and M7 lysin. These acrosomal proteins have egg vitelline lyses function and are highly similar (76%) which explains the cross reactivity of mAb G26-AG8. Furthermore, M7 lysin was recently shown to be under strong positive selection suggesting a role in interspecific reproductive isolation. This study shows that M6 and M7 lysin are not only found in the sperm acrosome but also in male somatic tissue of the mantle and the posterior adductor muscle, while being completely absent in females. The monoclonal antibody G26-AG8 described here will allow elucidating M7/M6 lysin function in somatic and gonad tissue of adult and developing animals. Mol. Reprod. Dev. 76: 4,10, 2009. © 2008 Wiley-Liss, Inc. [source] The transcription factor CREM, and cAMP regulate promoter activity of the Na,K-ATPase ,4 isoformMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 11 2006Marianna Rodova Abstract The Na,K-ATPase is an essential enzyme of the plasma membrane that plays a key role in numerous cell processes that depend on the transcellular gradients of Na+ and K+. Among the various isoforms of the catalytic subunit of the Na,K-ATPase, ,4 exhibits the most limited pattern of expression, being restricted to male germ cells. Activity of ,4 is essential for sperm function, and ,4 is upregulated during spermatogenesis. The present study addressed the transcriptional control of the human Na,K-ATPase ,4 gene, ATP1A4. We describe that a 5, untranslated region of the ATP1A4 gene (designated ,339/+480 based on the ATP1A4 transcription initiation site) has promoter activity in luciferase reporter assays. Computer analysis of this promoter region revealed consensus sites (CRE) for the cyclic AMP (cAMP) response element modulator (CREM). Accordingly, dibutyryl cAMP (db-cAMP) and ectopic expression of CREM,, a testis specific splice variant of CREM were able to activate the ATP1A4 promoter driven expression of luciferase in HEK 293 T, JEG-3 and GC-1 cells. Further characterization of the effect of db-cAMP and CREM, on deleted constructs of the ATP1A4 promoter (,339/+80, and +25/+480), and on the ,339/+480 region carrying mutations in the CRE sites showed that db-cAMP and CREM, effect required the CRE motif located 263 bp upstream the transcription initiation site. EMSA experiments confirmed the CRE sequence as a bonafide CREM, binding site. These results constitute the first demonstration of the transcriptional control of ATP1A4 gene expression by cAMP and by CREM,, a transcription factor essential for male germ cell gene expression. Mol. Reprod. Dev. 73: 1435,1447, 2006. © 2006 Wiley-Liss, Inc. [source] Superoxide dismutase content and fatty acid composition in subsets of human spermatozoa from normozoospermic, asthenozoospermic, and polyzoospermic semen samplesMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 4 2003J. Calamera Abstract Human ejaculated sperm comprised discrete subsets of spermatozoa, with different degrees of maturation. These subpopulations can be isolated through density gradient centrifugation. Sperm from the lowest density layer show the highest content of docosahexaenoic acid and sterols, and produce the highest levels of reactive oxygen species. The main objective of this study was to determine the superoxide dismutase (SOD) content and fatty acid composition of subsets of spermatozoa isolated from normozoospermic, asthenozoospermic, and polyzoospermic semen samples. Four sperm fractions (1,4) were obtained using ISolate gradient centrifugation. Morphology, motion parameters, SOD content, and fatty acid composition were assessed in the original samples and their fractions. Overall, sperm from normozoospermic samples had higher SOD content than those of asthenozoospermic or polyzoospermic samples. Once fractionated in subsets, the sperm SOD content decreased significantly (P,<,0.0001) from fraction 1 (top) to 4 (bottom) in all three groups of samples. Fatty acid content as well as the oxidation coefficient followed the same pattern, decreasing from fraction 1 to 4 (F1,F4). Normo- and polyzoospermic samples showed similar amounts of fatty acids, while asthenozoospermic samples mostly revealed increased levels. Normozoospermic samples displayed the lowest unsaturated fatty acid (UFA)/SOD ratio. Spermatozoa from astheno- and polyzoospermic samples, two common seminal pathologies, showed higher UFA and lower SOD content than normal sperm, therefore exhibiting a higher susceptibility to peroxidative damage. F4 from all groups, containing the most mature spermatozoa, displayed the lowest polyunsaturated fatty acid and SOD content of all subsets, suggesting that excessive SOD activity as well as abundant peroxidative targets may both be deleterious to sperm function. Mol. Reprod. Dev. 66: 422,430, 2003. © 2003 Wiley-Liss, Inc. [source] Novel human testis-specific cDNA: Molecular cloning, expression and immunobiological effects of the recombinant proteinMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 1 2001Ramasamy Santhanam Abstract A differential display-polymerase chain reaction was employed to obtain a testis-specific cDNA fragment. On screening the human testis-,gt10-cDNA library with testis-specific cDNA fragment, a novel cDNA encoding for a sperm antigen, designated TSA-1, was obtained. It has a novel open reading frame (ORF) of 471 base pairs encoding for 156 amino acids. The computer generated translated protein has a calculated molecular mass of 17.4 kDa and contains a potential N-glycosylation site at amino acids 122,124. The hydrophilicity analysis of the amino acid sequence suggested that this protein is a membrane-anchored peptide. Extensive analysis for tissue-specificity by Northern blots and RT-PCR-Southern blot procedures using various human tissues indicated that TSA-1 was specifically expressed only in the human testis. Based on the results of in vitro transcription and translation experiments, the TSA-1 (ORF) was subcloned into pGEX-6P-3 vector and expressed using the glutathione S -transferase gene fusion system. Antibodies (Ab) against the purified recombinant protein specifically recognized the ,17 kDa recombinant TSA-1, and a ,24 kDa band in human sperm extract in the Western blot procedure. The recombinant TSA-1 Ab recognized the acrosomal, equatorial, mid-piece, and tail regions of human sperm cell in indirect immunofluorescence, bound to live human sperm in the immunobeads binding technique (IBT) and caused a significant concentration-dependent inhibition of human sperm acrosome reaction. These findings indicate that the novel sperm-specific recombinant TSA-1 has a role in sperm function and may have applications in the development of a contraceptive vaccine, and in the specific diagnosis and treatment of male infertility. Mol. Reprod. Dev. 60: 1,12, 2001. © 2001 Wiley-Liss, Inc. [source] Mammalian Sperm Energy Resources Management and Survival during Conservation in RefrigerationREPRODUCTION IN DOMESTIC ANIMALS, Issue 2006JE Rodriguez-Gil Contents The present review has as its main aim to present an overview regarding the mechanisms utilized by mammalian sperm to manage its intracellular energy levels. This management will strongly influence the sperm's ability to maintain its overall function during its entire life span. Thus, the precise knowledge of these mechanisms will be of the utmost interest to optimize the systems utilized to conserve mammalian sperm for a medium-to-long time-lapse. Briefly, utilization of hexoses as energy substrates by mammalian sperm is very finely regulated from the very first step of its metabolization. Furthermore, the equilibrium among the separate, monosaccharide metabolization pathways in mammalian sperm depends on many factors. This prevents the possibility to draw a general vision of sperm energy utilization, which explains the results of all mammalian species in all points of the sperm life-cycle. To complicate the matter further, there are separate energy phenotypes among mammalian spermatozoa. The precise knowledge of these phenotypes is of the greatest importance in order to optimize the design of new extenders for sperm conservation in refrigerated conditions. Moreover, sugars can act on sperm not only as passive metabolic substrates, but also as direct function activators through mechanisms like specific changes in the tyrosine phosphorylation status of distinct proteins. Finally, mammalian sperm utilizes non-glucidic substrates like citrate and lactate to obtain energy in a regular form. This utilization is also finely regulated and of importance to maintain overall sperm function. This implies that the exact proportion of glucidic and non-glucidic energy substrates could be very important to optimize the survival ability of these cells in conservation. [source] ORIGINAL ARTICLE: The Role of Cytokine Expression in Different Subgroups of Subfertile MenAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 5 2009Srividya Seshadri Problem, The aim of this study was to evaluate the levels of seminal plasma cytokines interleukin 6 (IL-6), interleukin 8 (IL-8), interleukin 10 (IL-10), interleukin 11 (IL-11), interleukin 12 (IL-12), tumour necrosis factor alpha (TNF-,) and interferon gamma (IFN-,) in male subfertility. Method of study, A total of 73 male partners of an infertile couple attending a regional andrology unit were recruited into this prospective study and subdivided into the various groups based on semen analysis. Concentrations of cytokines such as IL-6, IL-8, IL-10, IL-11, IL-12, TNF-, and IFN-, in the seminal plasma were determined using enzyme linked immunosorbent assay (ELISA). Results, Significant higher concentrations (P < 0.05) of IL-6 in the mild and severe oligospermic group, IL-8 and IL-10 in the asthenospermic group and IL-6, IL-10, TNF-, and IFN-, in the obstructed azoospermic group were determined. IL-10 concentrations correlated significantly with other cytokines in the obstructed azoospermic group and the asthenospermic group. Conclusion, Our study confirms that cytokines rarely act in isolation, but rather in a network of other cytokines and may affect sperm function directly or indirectly. The presence of increased levels of cytokines in the obstructed azoospermic group suggests that the cytokines may not originate from the testis. [source] REVIEW ARTICLE: Status of Contraceptive VaccinesAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 1 2009Rajesh K. Naz Problem, This is a review of anti-sperm contraceptive vaccines (CV), and synthesis of human scFv antibodies that can be used as immunocontraceptives. Method of study, Various methods of proteomics and genomics, peptide synthesis, phage display technology, and antibody engineering were used to obtain multi-epitope vaccines and human scFv antibodies from immunoinfertile and vasectomized men. The present review primarily focuses on the effect of multi-epitope vaccines and Izumo on fertility, and synthesis and characterization of sperm specific human scFv antibodies. Results, The immunization with Izumo peptides causes a contraceptive effect in female mice. The efficacy is enhanced by combination vaccination, including peptides based on other sperm antigens. Using phage display technology, we were able to synthesize at least four novel scFv antibodies with unique complementarity determining regions (CDRs) that reacted with specific fertility-related sperm antigens. These antibodies inhibited human sperm function in vitro, and their immunocontraceptive effect in vivo by these antibodies is currently being investigated. Conclusion, The multi-epitope vaccines may provide an efficacious and viable approach to contraception. The human scFv antibodies, if they block fertility in vivo, may provide unique and novel immunocontraceptives, the first of its kind for human use. The multi-epitope CV and preformed engineered antibodies of defined specificity may obliterate the concern related to inter-individual variability of the immune response. [source] Effects of H2O2 exposure on human sperm motility parameters, reactive oxygen species levels and nitric oxide levelsANDROLOGIA, Issue 3 2010S. S. Du Plessis Summary Research has revealed that reactive oxygen species (ROS) negatively affect sperm function, both in vivo and in vitro. Sperm preparation techniques for assisted reproductive technologies (ART) are potential causes for additional ROS production. This study aimed to correlate the concentration of exogenous H2O2 with sperm motility parameters and intracellular ROS and nitric oxide (NO) levels to reiterate the importance of minimising ROS levels in ART. Human spermatozoa from 10 donors were incubated and exposed to different exogenous H2O2 concentrations (0, 2.5, 7.5 and 15 ,m). Subsequently, motility was determined using computer-aided semen analysis, while ROS (2,7-dichlorofluorescin diacetate) and NO (diaminofluorescein-2/diacetate) were analysed using fluorescence-activated cell sorting. Results showed that H2O2 did affect the sperm parameters. Exogenous H2O2 was detrimental to motility and resulted in a significant increase in overall ROS and NO levels. A significant increase in static cells was seen as well. It is important to elucidate the mechanisms between intracellular ROS levels with sperm motility parameters. While this experiment demonstrated a need to reduce exogenous ROS levels during ART, it did not illustrate the cause and effect relationship of intracellular ROS and NO levels with sperm motility. Further research needs to be conducted to define a pathological level of ROS. [source] The in vitro effects of melatonin on human sperm function and its scavenging activities on NO and ROSANDROLOGIA, Issue 2 2010S. S. Du Plessis Summary Various systems of antioxidants exist endogenously in the body to help protect it against free radical damage by scavenging excessive ROS and RNS. Melatonin, a hormone secreted by the pineal gland, and responsible for controlling the circadian rhythm, is one such endogenous antioxidant. Melatonin has been reported to be present in human seminal fluid, but its antioxidant activities in semen are rather contradictory. This study aimed at establishing the effects of melatonin treatment on human spermatozoa. Spermatozoa were incubated with 2 mm melatonin (120 min, 37 °C, 5% CO2) after which motility parameters were measured by computer aided motility analysis, while cell viability (PI), intracellular NO (DAF-2/DA) and ROS (DCFH-DA) were assessed using flow cytometry. In vitro melatonin treated samples (n = 12) showed a significantly higher percentage of motile, progressive motile and rapid cells, while simultaneously reducing the number of nonviable spermatozoa when compared with the control. Endogenous NO was significantly decreased, but no effect was observed on ROS levels. From these results, it can be concluded that melatonin was able to directly or indirectly scavenge NO, as indicated by the reduction in 4,5-diaminofluorescein-2/diacetate fluorescence. Future studies will indicate whether melatonin treatment during sperm preparation techniques could protect spermatozoa from excessive NO production. [source] Mast cells in the seminal plasma of infertile men as detected by flow cytometryANDROLOGIA, Issue 1 2009J.-P. Allam Summary Increased numbers of mast cells (MCs) in the testis have been associated with testicular dysfunction, where accumulation of MCs occurs. Furthermore, it has been reported that MCs might affect sperm function as it has been demonstrated that MC-derived tryptase in the seminal fluid might reduce sperm motility. Although MCs have been detected in rat epididymis, only little is known about the presence of MCs in human seminal plasma. Thus, we analysed MC numbers in the ejaculate of men during routine semen analysis of male patients suspected for infertility (n = 100). MCs were detected by c-kit (CD117) expression using flow cytometry. Thereby, we detected significant numbers of MCs in the ejaculate of most patients (559 ± 525 MCs ml,1, mean ± SD). However, we could neither detect a correlation with respect to MCs and sperm count, motility or morphology nor to the seminal inflammatory markers like polymorphonuclear elastase. Nevertheless, a significant correlation of MCs to spermatozoa-bound IgA (r = 0.5; P = 0.03; n = 21) was observed. It is concluded that significant numbers of MCs can be detected in the human ejaculate without necessarily influencing sperm function. A potential role of MCs in seminal plasma as well as the association between MCs and IgA on spermatozoa remains to be elucidated. [source] Influence of sexual stimulation on sperm parameters in semen samples collected via masturbation from normozoospermic men or cryptozoospermic men participating in an assisted reproduction programmeANDROLOGIA, Issue 3 2000Y. Yamamoto Summary. To evaluate the influence of sexual stimulation via sexually stimulating videotaped visual images (VIM) on sperm function, two semen samples were collected from each of 19 normozoospermic men via masturbation with VIM. Two additional samples were collected from each man via masturbation without VIM. The volume of seminal plasma, total sperm count, sperm motility, percentage of morphologically normal spermatozoa, outcome of hypo-osmotic swelling test and zona-free hamster oocyte sperm penetration assay, and markers of the secretory function of prostate were significantly larger in semen samples collected via masturbation with VIM than masturbation without VIM. The improved sperm parameters in the samples collected via masturbation with VIM may reflect an enhanced prostatic secretory function and increased loading of the vas deferens at that time. In a similar protocol, two semen samples were collected via masturbation with VIM from each of 22 non-obstructed azoospermic men. Semen samples from these men had been occasionally positive in the past for a very small number of spermatozoa (cryptozoospermic men). Two additional samples were collected from each cryptozoospermic man via masturbation without VIM. The volume of seminal plasma, total sperm count, sperm motility, and a marker of the secretory function of prostate were significantly larger in semen samples collected via masturbation with VIM. Fourteen out of the 22 men were negative for spermatozoa in both samples collected via masturbation without VIM. These men demonstrated spermatozoa in both samples collected via masturbation with VIM. Six men with immotile spermatozoa in both samples collected via masturbation without VIM exposed motile spermatozoa in both samples collected via masturbation with VIM. High sexual stimulation during masturbation with VIM results in recovery of spermatozoa of greater fertilizing potential both in normozoospermic and cryptozoospermic men. The appearance of spermatozoa after masturbation with VIM in the vast majority of cryptozoospermic men is of clinical significance in programmes applying intracytoplasmic sperm injections for the management of severe male infertility and obviates the need for testicular biopsy. [source] Effect of leptin on motility, capacitation and acrosome reaction of human spermatozoaINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 6 2009H. W. R. Li Summary Leptin is a polypeptide hormone with important roles in reproduction. It has been detected in human seminal plasma as well as on human ejaculated spermatozoa. This study aimed at studying the possible role of leptin in regulating human sperm functions. Immunofluorescent staining was used to study the expression of leptin and its receptor. The correlation between the concentration of leptin and soluble leptin receptor (ObRs) in seminal plasma as measured by enzyme-linked immunosorbant assay and sperm motility parameters measured by computer-assisted sperm analyais (CASA) was determined. The effects of recombinant leptin on human sperm motility, capacitation and acrosome reaction as measured by chlortetracycline staing were also studied. Leptin immunoreactivity was demonstrated at the equatorial and neck regions of human spermatozoa, whereas that of ObRs was shown up on the tail. After Percoll separation, spermatozoa with high density had more intense leptin immunoreactivity compared with those with low density. No significant correlation was found between seminal plasma concentration of leptin/ObRs and sperm motility parameters. After incubation with recombinant human leptin for either 3 h or overnight, there was no change in all the CASA motility parameters determined and percentages of capacitated and acrosome-reacted spermatozoa. We concluded that leptin does not have a significant effect on motility and capacitation/acrosome reaction in human ejaculated mature spermatozoa. Its role in male reproduction is yet to be determined. [source] Localization of Hyaluronic Acid in the Seminal Vesicles of the Miniature PigANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2007A. Sakairi Summary We studied the detailed localization of hyaluronic acid in the seminal vesicles of the miniature pig, using hyaluronic acid-binding protein as a specific histochemical probe at the ultrastructural level. According to the results, the basolateral surface of the plasma membrane of the glandular epithelial cells, was found to contain hyaluronan. However, abundantly present was hyaluronan in the subepithelial connective tissue, in particular, in the extracellular matrix surrounding the fibroblasts, smooth muscle cells, small blood vessels and capillaries. The substance was also observed in the surface coat of the plasma membrane of the fibroblasts, but not in that of the smooth muscle cells. The findings suggest that hyaluronan in the seminal vesicles of the miniature pig is synthesized onto the surface coat of the plasma membrane of the fibroblasts, is contributed to the extracellular matrix, and consequently concentrates in the subepithelial connective tissue. The substance may particularly be involved in a variety of cellular functions to maintain morphological organization as well as to regulate physiological homeostasis in the reproductive organ of this species, rather than participate in sperm functions. [source] Acrosome reaction in Chlamydia-positive and negative patientsANDROLOGIA, Issue 5 2003A. Jungwirth Summary. Chlamydia trachomatis infections might have a detrimental effect on various sperm functions. Data concerning the effect of C. trachomatis on the capacitation activity of sperms are lacking. The study was undertaken to evaluate whether chlamydial infection influences acromsome reaction (AR). Three groups of men were investigated for ARs - Chlamydia negative (n = 46) and positive (n = 30) patients, and healthy men (n = 53) undergoing vasectomy. The fluorescence technique for the evaluation of AR was applied. The normal range for the induction of AR was assumed ,AR > 12.5% for this technique. Seminal plasma was examined for IgA antibodies against C. trachomatis. There was a significant difference in AR between healthy volunteers, Chlamydia-negative and Chlamydia- positive patients. ,ARs were 15.8 ± 1.6% in healthy volunteers versus 12.15 ± 2.4% in Chlamydia- negative and 9.08 ± 1.8% in Chlamydia- positive patients, respectively (P <0.05). Significant elevated titres of C. trachomatis- specific IgA in seminal plasma showed a negative correlation with the AR of spermatozoa. AR seems to be a valuable marker, especially in couples with idiopathic infertility. [source] | |||||||||||||