少弱精症

… It is defined as a condition in which spermatozoa in the ejaculated semen are dead. … In a cohort of patients with extensive and persistent disorder of motility, subclinical seminal infections …

… a person with no ciliary disorder and with oriented basal feet (… of the semen to differentiate between dead spermatozoa and … be classified as necrospermia, meaning dead spermatozoa; …

During routine evaluation of trypan blue-Giemsa stained semen smears, sperm cells can be found with unstained heads and with stained tails. It was hypothesized that these cells were immotile and should not be considered as live. Sperm motility was determined in isoosmotic, and presumably isotonic trypan blue-stained wet preparations. Bull, ram and boar semen smears were stained with hypoosmotic trypan blue-Giemsa to compare the relationship between the percentage of stained sperm tails and the percentage of sperm tails remaining straight under hypoosmotic conditions. Actively moving spermatozoa with unstained heads, but with stained tails were never observed in wet preparations. The correlation coefficient found between the percentage of sperm with stained tails and the percentage with straight tails was 0.81, 0.94 and 0.85 for bull, ram and boar spermatozoa, respectively. Results of this study show that sperm cells with an intact head membrane, but a stained and presumably membrane-damaged tail are not motile. Therefore these cells should be included in the dead category rather than alive in the usual live-dead studies with vital stains.

… examined in this study technically can be used for differentiation between live and dead spermatozoa in canine semen samples, but the relatively high CVs have to be kept in mind. It is …

… treatments using spermatozoa stained with CAL and PI. Population 1 was quantified as membrane damaged or dead spermatozoa stained with PI; Population 2 was the living cells that …

… only by SYBR-14 and exhibit green fluorescence, while the dead cells with damaged membranes are stained in both dyes and fluoresce red light caused by propidium iodine [11, 12]. …

An acrosomal staining technique that can differentiate between living and dead sperm was developed for equine sperm. The fluoresceinated lectin Pisum sativum agglutinin (FITC-PSA) was used to identify the presence or absence of acrosomal contents, while the supravital nuclear dye Hoechst 33258 (H258) was used to assess viability. The accuracy of the FITC-PSA acrosomal stain was tested by comparing the percentage of sperm that had lost their acrosomal contents, detected by the staining method, with that detected by transmission electron microscopy (TEM). Following capacitation in vitro, the acrosomal status of sperm induced to acrosome react with A23187 and of control sperm were very similar with the staining technique and TEM, confirming the accuracy of the FITC-PSA acrosomal stain. We investigated the relationship between viability as measured by exclusion of H258 and motility as measured by three methods: one subjective and two objective. Although there was a good correlation between viability and motility as measured by all three methods (r = 0.88, 0.85, 0.75), there was always a proportion of viable sperm that were nonmotile. The physiology of the viable, nonmotile sperm was further investigated by comparing for individual sperm the viability as measured by exclusion of H258 with the mitochondrial function as measured by rhodamine 123. A good correlation (r = 0.99) was found to exist between viability and mitochondrial function, indicating that viable, nonmotile sperm possess functional mitochondria and confirming the ability of supravital staining to distinguish between living and dead sperm. We determined that 29-81% of the sperm in semen that had lost their acrosomal contents were in fact dead. Thus, this acrosomal staining technique can provide more relevant endpoints for future investigations of capacitation, the acrosome reaction, and sperm handling techniques in the horse.

… of stained (dead) cells in sperm samples by microscopic analysis using eosin/nigrosin-stained … We classified such cells as dead (stained), since they probably …

… transient and lead to cell death. In conclusion, the … sperm plasma membrane at an earlier point than PI staining, thus representing a novel approach to investigating membrane integrity …

The aim of this study was to determine sperm membrane integrity and mitochondrial activity, to quantify possible apoptosis, and to investigate relationship between these parameters. Apoptotic-like changes were evaluated using a combination of YO-PRO-1/PI staining, and changes in mitochondrial membrane potential were evaluated using JC-1. Gel-free ejaculates collected from fi ve boars were extended in BTS diluent and stored for six days at 15-17°C. The fl uorescence analysis was repeated on the fi rst, third and sixth day of semen storage. Motility was also assessed on each day of the experiment. The percentage of apoptotic sperm detected by YO-PRO-1/PI staining inconsiderable decreased, while number of necrotic sperm increased during six days storage. The percentage of spermatozoa with mitochondrial membrane potential (∆Ψm) dysfunction increased and reached the highest level at day six of semen storage. The ∆Ψm analysis by JC-1 revealed that mitochondrial function was highly correlated with both sperm motility (r=0.936) and apoptosis/necrosis evaluated by the YO-PRO-1/PI assay (r=0.960).

Simple Summary The cell membrane of spermatozoa is the main structural element of these gametes. In boars, due to its structure, it is most susceptible to various types of damage induced by various factors. Artificial insemination in pigs mainly involves the use of liquid semen preserved at 17 °C. Thus, it is important to monitor this semen during its storage. In practice, the changes that can take place in sperm during the preservation and storage of boar semen are not analysed. Furthermore, considerable variation is observed in the characteristics of boar semen, which may depend on the breed or crossbreeding variant of the boar. Crossbred boars are often used in artificial insemination, because they not only easily produce ejaculates with good parameters, but also have good libido characteristics. However, despite the benefits of artificial insemination with semen of crossbred boars, there is insufficient knowledge of the sensitivity of cell structures to conditions associated with semen storage in comparison with boars of the parent breeds. For this reason, a study was conducted to analyse changes in the integrity of sperm cell membranes taking place during the storage of semen collected from Duroc × Pietrain crossbred boars and purebred boars of the parent breeds. The sperm of Duroc × Pietrain crossbred boars were found to be less sensitive to the conditions of semen storage and to better retain cell membrane integrity than the sperm of purebred males, which was confirmed by calculating the heterosis effects for semen assessed at different hours of storage at 17 °C. Abstract The aim of the study was to assess changes in the integrity of sperm cell membranes during the storage of semen collected from Duroc × Pietrain crossbred boars and purebred boars of the component breeds. To compare the cell membrane integrity of sperm heads in crossbred and purebred boars, heterosis effects were estimated. The study was conducted on 48 ejaculates collected from Duroc × Pietrain crossbred boars and from purebred Duroc and Pietrain boars used for artificial insemination. Microscope slides were prepared from each ejaculate for the evaluation of the cell membrane integrity of the sperm, at 1, 24, 48, 72, and 96 h after collection of the ejaculate. Diluted ejaculates were stored at 17 °C. Sperm membrane integrity was analysed by two methods: SYBR-14/PI and eosin–nigrosin. Our results showed that the cell membrane integrity of sperm heads changed with storage time, but the extent of the changes varied depending on the genetic group of boars. The semen of Duroc × Pietrain crossbreds was clearly seen to be less sensitive to storage conditions than that of boars of the parent breeds, which was confirmed by the calculated heterosis effects. The percentage of sperm with an intact cell membrane was higher in crossbred boars than in purebred boars (p ≤ 0.05). In addition, significantly fewer moribund sperm spermatozoa and spermatozoa with a damaged cell membrane were observed in crossbred boars (p ≤ 0.05). In the semen of purebred Duroc and Pietrain boars, the cell membrane integrity of the sperm should be assessed more often during storage than in the semen of Duroc × Pietrain crossbred boars. This study provides valuable information for the development and implementation of semen quality monitoring in crossbred boars and boars of the parent breeds during storage at 17 °C with respect to the cell membrane structure of sperm heads. The evaluation methods used effectively identify damage to the cell membranes of the sperm during semen storage.

Summary. Carboxyfluorescein diacetate and propidium iodide were used as fluorescent stains to assess membrane integrity in sperm populations from ram and boar. The living spermatozoa were immobilized with low concentrations of formaldehyde so that individual stained cells could be observed in a suspension with the aid of a fluorescence microscope. Intracellular esterases liberated impermeant-free carboxyfluorescein from the permeant carboxyfluorescein diacetate and caused the product to accumulate and fluoresce green within the acrosome and the mitochondria as well as within the cytoplasm. Most of the spermatozoa (the intact ones) accumulated carboxyfluorescein in all compartments; however, a few cells (those with damaged plasma membranes) accumulated the stain only in the acrosome and/or the mitochondria, while others (all of whose membranes were damaged) remained entirely unstained. The impermeant propidium iodide did not stain any of the (intact) spermatozoa that accumulated carboxyfluorescein throughout their length, but stained all the others (the heads fluoresced red). The technique appeared to provide more reliable estimations of the percentage of functional cells than did motility estimations or assessments of acrosomal integrity (presence of normal apical ridge). The technique also demonstrated the sensitivity of the sperm plasma membrane to cold shock: virtually all cells rapidly became permeable to the stains after such stress. Assessments of boar sperm samples during preparative incubation for in-vitro fertilization indicated a considerable increase in the percentage of cells with damaged plasma membranes as incubation proceeded, in advance of the increase in the percentage of cells with discharged acrosomes. Keywords: spermatozoa; fluorescent probes; membranes

… Sperm membrane integrity (SMI) is thought to be an important measure of stallion … [3] further suggested that using two stains that react only with ‘live’ and ‘dead’ (membrane intact or …

Boar, bull and ram spermatozoa were examined after staining with the DNA-permeant Hoechst 33342 fluorochrome and flow cytometric sorting in the presence or absence of seminal plasma. Spermatozoa were assessed for viability with flow cytometry using the live cell nucleic acid stain SYBR-14 and propidium iodide (PI), and for membrane integrity using fluorescein isothiocyanate-conjugated Pisum sativum (FITC-PSA) and PI; motility and acrosome integrity were estimated by microscopy. Flow cytometric sorting was compared with pipette dilution of boar and bull spermatozoa into: (1) medium [boar: Test buffer containing 2% yolk (TY) or Beltsville thawing solution (BTS); bull: TY or HEPES buffer containing 0.1% bovine serum albumin (HEPES-BSA)] with or without 10% (v/v) seminal plasma; or (2) an empty tube containing no medium. Sorted spermatozoa were either not centrifuged or centrifuged before assessment during a 4-h holding period. The viability, motility and membrane integrity of boar, bull and ram spermatozoa centrifuged after sorting were also examined when seminal plasma was present or absent from the staining extender and/or the TY collection medium. The results indicate that the viability and membrane integrity of spermatozoa in vitro would be improved if: (1) seminal plasma (10%) was routinely included in the BTS and HEPES-BSA staining extenders for boar spermatozoa and ram spermatozoa, respectively, when used in preparation for flow cytometric sorting; and (2) 10% and 50% seminal plasma were included in the TY collection medium for boar or bull spermatozoa and ram spermatozoa respectively.

… Dead spermatozoa stained dark blue while live spermatozoa appeared pink. Intact acrosomes were purple, loose and damaged acrosomes were lavender, and the anterior part of …

… membranes from 87% of all sperm cells as determined by electron microscopy. Live/dead staining … samples in order to compare dye exclusion, and hence membrane integrity data with …

… The dye exclusion tests such as eosin–nigrosin are based on … Purple MTT formazan products called dye grains or spikes can be … a new diagnostic test using MTT for sperm viability test. …

… carrying out dye exclusion tests or by … dye and various fluorescent dyes such as Hoechst 33342, DAPI, PI and SYBR-14 including their combination for determining spermatozoa viability…

Turkey sperm viability was evaluated using several fluorescent stains both singularly and in combination. Dilution curves and several extenders were used to determine optimal stain concentrations. Semen was collected from eight toms, pooled, diluted, stained, and evaluated microscopically within 2 h of collection. Replicates were assessed for both viable and nonviable sperm (green and red fluorescence, respectively) using flow cytometry. SYBR-14, which likely requires membrane potential for optimal fluorescence, or Calcein AM (CAL), which assesses the membrane integrity of cells (both green fluorescence), in combination with propidium iodide (PI) to stain the dead or degenerating cells (red fluorescence) provided optimal results. Sperm were killed by unprotected freeze-thawing to provide mixed aliquots containing known amounts of fresh:killed sperm. The percentage of viable sperm, as determined by SYBR-14 with PI or CAL with PI staining, were 76.6, 58.8, 39.3, 20.1, 8, and 73.5, 55.8, 36.0, 17.1, .4, respectively, for ratios of 100:0, 75: 25, 50:50, 25:75, and 0:100 of fresh:killed mixtures. Semen from 30 individual toms was collected on 2 d and examined in replicate using these staining combinations. The proportion of viable sperm, as indicated by uptake of SYBR-14 or CAL stain, ranged from 55.8 to 86.7 and 38.0 to 86.1, respectively. Staining combinations were effective in estimating the viability of turkey sperm and could be useful for monitoring sperm viability before and after storage.

… plasma membrane integrity with the four dye combinations and sperm motility by CASA. Three … actual values of sperm viability in experiment 2 was evaluated by linear regression test. In …

… Finally sperm viability was assessed as cells excluding … is the most efficient test to evaluate sperm quality during the … Sperm cells were labelled either with the ΔΨm-sensitive dye 3,3…

… of sperm quality, which pursue the integration of different tests … the viability dye TO-PROÒ-3, after incubating spermatozoa … bull semen in relation with sperm viability, chromatin structure, …

Standard spermiograms describing sperm quality are mostly based on the physiological and visual parameters, such as ejaculate volume and concentration, motility and progressive motility, and sperm morphology and viability. However, none of these assessments is good enough to predict the semen quality. Given that maintenance of sperm viability and fertilization potential depends on membrane integrity and intracellular functionality, evaluation of these parameters might enable a better prediction of sperm fertilization competence. Here, we describe three feasible methods to evaluate sperm quality using specific fluorescent probes combined with fluorescence microscopy or flow cytometry analyses. Analyses assessed plasma membrane integrity using 4',6-diamidino-2-phenylindole (DAPI) and propidium iodide (PI), acrosomal membrane integrity using fluorescein isothiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA) and mitochondrial membrane integrity using 5,5',6,6'-tetra-chloro-1,1',3,3'-tetraethylbenzimidazolyl carbocyanine iodide (JC-1). Combinations of these methods are also presented. For instance, use of annexin V combined with PI fluorochromes enables assessing apoptosis and calculating the proportion of apoptotic sperm (apoptotic index). We believe that these methodologies, which are based on examining spermatozoon membranes, are very useful for the evaluation of sperm quality.

… morphology and sperm viability without interference by sperm activity was needed. … However, as only a limited number of media components were tested, it would be appropriate to …

… test for sperm viability is questionable because these methods rely on a relatively small population of spermatozoa (up to … have been proposed to determine sperm viability in a variety of …

… Sperm viability at each point was compared with the sperm viability at 10 min after addi— … These samples were subjected to the sperm test by FCM and microscopic observation. The …

… dye and Rhodamine-conjugated secondary antibodies were used to score sperm simultaneously for viability and … and sperm immobilization tests erroneously equate sperm motility with …

The season may affect the values of fresh semen variables and therefore influence the success of cryopreservation. The aim of this study was to improve the evaluation of seasonal changes in semen quality in Spanish Black Castellana roosters maintained under natural environmental conditions. Semen was collected from 11 Black Castellana roosters (housed under natural photoperiod and temperature conditions) by massage twice every month for 12 mo. In addition to determining ejaculate volume, sperm concentration, and sperm motility (the classic sperm variables), we used the hypo-osmotic swelling test to examine the membrane integrity of the spermatozoa. Further, morphological abnormalities and acrosome integrity were assessed via aniline blue staining. Semen volume (P < 0.05), sperm concentration (P < 0.01), and the percentage of spermatozoa with an intact acrosome (P < 0.01) were significantly affected by the season of the year. The annual profile of the percentage of spermatozoa showing acrosome integrity followed a trend roughly parallel to annual variations in temperature (Spearman rank correlation = 0.77, P < 0.01). According to the hypo-osmotic swelling test, membrane integrity fell in July (P < 0.05 compared with all other months), the month of highest temperatures. Aniline blue staining and the hypo-osmotic swelling test provide an easy and useful means of evaluating sperm abnormalities, including acrosome morphology and membrane integrity, and could be easily introduced into routine avian semen quality assessments. The results show that high semen quality is associated with long day photoperiods. Extreme heat or cold appear to exert a negative influence on sperm quality.

… sperm viability. The information obtained would be useful for designing novel clinical tests to identify normal sperm … to PI (a DNA intercalating dye), turning the sperm cell from blue to red-…

SummaryThe resazurin reduction test (RRT) is a useful technique to assess the metabolic rate of sperm cells. RRT depends on the ability of metabolically active cells to reduce the non-fluorescent dye resazurin to the fluorescent resorufin. The aim of this study was to develop a vital fluorometric method to evaluate metabolic activity of rabbit sperm cells. Twenty-five rabbit males were included in the study. Viability and morphology, motility and metabolic activity were evaluated using an eosin-nigrosin staining, a computer-assisted semen analysis (CASA) and the RRT, respectively. Spearman rank correlation analysis was used to determine the correlation between RRT and semen parameters. After evaluation, a concentration of 10 × 106 sperm cells/ml was selected for further experiments with RRT. No significant correlation was found between the RRT results and the motility parameters. However, after RRT a significant positive correlation between relative fluorescence units and the percentage of alive spermatozoa (r = 0.62; P = 0.001) and a negative one with the percentage of sperm cells with acrosomic abnormalities (r = −0.45; P &lt; 0.05) were detected.The vital assessment of metabolic rate of sperm cells by RRT could provide more information about semen quality than other routine semen analysis, correlating with sperm viability and acrosome status information.

… between live and dead sperm, because most of the sperm are immotile. The … with spermatozoa extracted from the testis because of low sperm count. In this report, immotile spermatozoa …

… Therefore, the special emphasis should go how to select immotile but living sperm from the ejaculate. This is offered by the use of the HOS test, a method which does not adversely …

… immotile sperm with gross structural defects who nonetheless achieved a normal offspring using testicular sperm … Therefore, one must differentiate live and dead immotile spermatozoa …

This study investigated the interrelationships between sperm plasma membrane integrity, motility, and DNA fragmentation (SDF) to provide a more holistic understanding of male fertility. A total of 1159 ejaculates were analyzed for sperm membrane integrity (% dead spermatozoa), motility (% immotile spermatozoa), and SDF (% sperm with fragmented DNA). The statistical methods included non-parametric correlation analysis and artificial intelligence (AI)-generated cluster analysis to identify patterns based on these three parameters. The results showed a moderate correlation (ρ = 0.65; p < 0.000) between sperm membrane integrity and motility, indicating that immotile sperm were more likely to exhibit membrane damage. A weak correlation (ρ = 0.21; p < 0.000) suggested that DNA damage was largely independent of the other sperm parameters. Cluster analysis identified three main clusters: Cluster 0: high levels of low membrane integrity, immotile sperm, and moderate DNA fragmentation. Cluster 1: moderate membrane integrity and motility but extremely high DNA fragmentation. Cluster 2: the lowest levels of membrane damage, immotile sperm, and DNA fragmentation, indicating overall better sperm quality. The clustering techniques demonstrated their ability to integrate multiple sperm parameters, enabling a more individualized fertility diagnosis and potentially enhancing male infertility assessments.

… characterized by poor sperm motility and a high proportion of dead sperm in the ejaculate. … : Deficiency of protein carboxyl methylase in immotile spermatozoa of infertile men. N Engl J …

This review briefly summarises the cellular and physiological aspects of sperm motility (SM) and viability from the point of view of male fertility/infertility. We discuss the SM patterns and maturation processes during the epididymal transit, including the effects of seminal plasma proteins, and while moving through the female reproductive tract. In connection with SM and viability, the oxidative stress, the mitochondrial markers of SM and related predictive value of the proportion of motile sperm, and the effect of male age on sperm function are reviewed within the current literature. Furthermore, some of the potential techniques to determine molecules involved in sperm motion are presented. Other key points are sperm maturation and the markers of sperm maturity, including sperm-hyaluronic acid binding and DNA integrity, as well as the proportion of hyaluronic acid-bound sperm with respect to sperm morphology and tyrosine phosphorylation. Finally, proteins regulating SM and assessment approaches of sperm viability are pointed out in this review.

The aim of this study was to analyze human sperm motility, viability, and morphology before and after cryopreservation. This true laboratory experimental study had pre and post randomized one group design. The study was conducted at the Embryology, Andrology, and Genetics Laboratory, Department of Medical Biology, Faculty of Medicine, Universitas Airlangga from August to November 2017. The eighteen samples of fresh semen were collected from male volunteers who agreed and signed the informed consent of the study. Samples were analyzed their motility, viability, and morphology before and after cryopreservation. Results of this study indicated differentiation between motility before and after cryopreservation. Cryopreservation process decreased progressive motility (42.22 + 9.46%; 17.83 + 6.24%; p< 0.0001) and increased the number of immotile spermatozoa (35.44 + 10.15%; 60.11 + 12.53%; p< 0.0001). Cryopreservation also decreased human sperm viability (73.78 + 8.91%; 40.83 + 12.89%; p< 0.0001) and morphology (10.94 + 4.96%; 7.39 + 3.90%; p< 0.0001). Cryopreservation of human spermatozoa caused the decreased of motility, viability, and morphology.

… Viability assessed by HOS-test and total sperm motility evaluated automatically were determined in each sample. The purpose of this study was to establish a relationship …

… Apoptosis is a process of programmed cell death that occurs in many cells throughout the body. In the testes, apoptosis normally occurs to prevent the overproduction of germ cells and …

Despite the high prevalence of male infertility, very little is known about its etiology. In recent years however, advances in gene sequencing technology have enabled us to identify a large number of rare single point mutations responsible for impeding all aspects of male reproduction from its embryonic origins, through the endocrine regulation of spermatogenesis to germ cell differentiation and sperm function. Such monogenic mutations aside, the most common genetic causes of male infertility are aneuploidies such as Klinefelter syndrome and Y-chromosome mutations which together account for around 20–25% of all cases of non-obstructive azoospermia. Oxidative stress has also emerged as a major cause of male fertility with at least 40% of patients exhibiting some evidence of redox attack, resulting in high levels of lipid peroxidation and oxidative DNA damage in the form of 8-hydroxy-2'-deoxyguanosine (8OHdG). The latter is highly mutagenic and may contribute to de novo mutations in our species, 75% of which are known to occur in the male germ line. An examination of 8OHdG lesions in the human sperm genome has revealed ~9,000 genomic regions vulnerable to oxidative attack in spermatozoa. While these oxidized bases are generally spread widely across the genome, a particular region on chromosome 15 appears to be a hot spot for oxidative attack. This locus maps to a genetic location which has linkages to male infertility, cancer, imprinting disorders and a variety of behavioral conditions (autism, bipolar disease, spontaneous schizophrenia) which have been linked to the age of the father at the moment of conception. We present a hypothesis whereby a number of environmental, lifestyle and clinical factors conspire to induce oxidative DNA damage in the male germ line which then triggers the formation de novo mutations which can have a major impact on the health of the offspring including their subsequent fertility.

Reactive oxygen species (ROS) play a critical role in defining the functional competence of human spermatozoa. When generated in moderate amounts, ROS promote sperm capacitation by facilitating cholesterol efflux from the plasma membrane, enhancing cAMP generation, inducing cytoplasmic alkalinization, increasing intracellular calcium levels, and stimulating the protein phosphorylation events that drive the attainment of a capacitated state. However, when ROS generation is excessive and/or the antioxidant defences of the reproductive system are compromised, a state of oxidative stress may be induced that disrupts the fertilizing capacity of the spermatozoa and the structural integrity of their DNA. This article focusses on the sources of ROS within this system and examines the circumstances under which the adequacy of antioxidant protection might become a limiting factor. Seminal leukocyte contamination can contribute to oxidative stress in the ejaculate while, in the germ line, the dysregulation of electron transport in the sperm mitochondria, elevated NADPH oxidase activity, or the excessive stimulation of amino acid oxidase action are all potential contributors to oxidative stress. A knowledge of the mechanisms responsible for creating such stress within the human ejaculate is essential in order to develop better antioxidant strategies that avoid the unintentional creation of its reductive counterpart.

… of sperm DNA fragmentation (sDF) found in sub-/infertile men threat … in dead ejaculated spermatozoa, whereas oxidative stress is likely inducing sDF during the transit through the male …

The spermatozoon is a highly specialized cell, whose main function is the transport of the intact male genetic material into the oocyte. During its formation and transit throughout male and female reproductive tracts, sperm cells are internally and externally surrounded by reactive oxygen species (ROS), which are produced from both endogenous and exogenous sources. While low amounts of ROS are known to be necessary for crucial physiological sperm processes, such as acrosome reaction and sperm–oocyte interaction, high levels of those species underlie misbalanced antioxidant-oxidant molecules, generating oxidative stress (OS), which is one of the most damaging factors that affect sperm function and lower male fertility potential. The present work starts by reviewing the different sources of oxidative stress that affect sperm cells, continues by summarizing the detrimental effects of OS on the male germline, and discusses previous studies addressing the consequences of these detrimental effects on natural pregnancy and assisted reproductive techniques effectiveness. The last section is focused on how antioxidants can counteract the effects of ROS and how sperm fertilizing ability may benefit from these agents.

… enzymes in bovine spermatozoa, which are active only in dead spermatozoa and actively … capacitation to the etiology of infertility and DNA damage in the germ line. Antioxid. Redox …

… spermatozoa; such cells were only stained following sperm demembranation with 1% Triton X-… Key words: immunogold electron microscopy/infertility/monoclonal antibody/necrospermia/…

Abstract A major factor affecting male fertility is excessive death of germ cells, both immature germ cells and mature spermatozoa. It can be due to various factors causing testicular and/or post-testicular damage, such as infections, obstructive conditions, toxins, oxidative stress, hormonal imbalance, hyperthermia, and anti-sperm antibodies. Massive death of spermatozoa leads to a high proportion of dead sperm cells in the ejaculate (necrozoospermia or necrospermia) while death of immature germ cells can lead to low sperm count (oligozoospermia or oligospermia). Cell death can occur both by necrosis and by apoptosis; in recent decades, it has been found that apoptosis of mature spermatozoa is not only possible but quite common, and can contribute to infertility. Treatment approaches are primarily directed to the underlying condition, i.e. removing the cause(s) of sperm cell death whenever possible, but include also attempts to bypass the cell death event by intracytoplasmic sperm injection with testicular spermatozoa.