The role of the intrinsic pathway of apoptosis in human ejaculated sperm damage under a state of scrotal heat stress

PURPOSE

The study aimed to determine the associations among standard sperm characteristics and oxidative/apoptotic markers in ejaculated sperm of men exposed to prolonged scrotal hyperthermia of either environmental or clinical origin.

METHODS

The original study design included four research groups: professional drivers (n = 54), infertile men with varicocele (n = 78), infertile men not exposed to prolonged genital heat stress (n = 37), and fertile individuals serving as the control group (n = 29). Standard semen analysis was performed according to the 5th WHO laboratory manual. The following oxidative and apoptotic parameters of sperm were investigated: mitochondrial superoxide anion generation (MitoSOX Red dye), phosphatidylserine externalization (Annexin V binding assay), mitochondrial membrane potential (JC-1 dye), DNA fragmentation (TUNEL/PI assay), and membrane fluidity (merocyanine 540 dye).

RESULTS

All the studied groups presented a strong deterioration in routine sperm parameters and a strongly apoptotic phenotype in sperm, characterized by both decreased mitochondrial membrane potential and enhanced DNA fragmentation, regardless of the thermal insult. Significant induction of mitochondrial superoxide anion generation was noted only in the groups exposed to genital heat stress. A positive correlation between the production of superoxide anion in the mitochondrial chain and the level of DNA fragmentation in drivers was also noted.

CONCLUSION

Long-term exposure to scrotal hyperthermia in real-life situations is sufficient to reduce sperm quality in humans. The thermal stress directly induces the oxidative stress cascade in ejaculated sperm, affecting the plasma membrane fluidity, mitochondrial homeostasis, and sperm DNA integrity.

Male Infertility Coexists with Decreased Sperm Genomic Integrity and Oxidative Stress in Semen Irrespective of Leukocytospermia

Our research was designed to verify the relationship between male infertility, basic semen characteristics (with respect to detailed sperm morphology), sperm DNA fragmentation (SDF), oxidation-reduction potential in semen (ORP), and leukocytospermia. The obtained results showed that infertile groups (with or without leukocytospermia) had significantly lower basic semen characteristics and higher SDF, raw ORP, and static ORP (sORP) than fertile controls. The thresholds of 13% SDF (AUC = 0.733) and 1.40 sORP (AUC = 0.857) were predictive values for discriminating infertile from fertile men. In infertile groups, a higher prevalence and risk for >13% SDF and >1.40 sORP were revealed. Unexpectedly, leukocytospermic subjects had lower sORP, prevalence, and risk for >1.40 sORP than leukocytospermic-negative men. These groups did not differ in SDF and raw ORP. Both SDF and sORP negatively correlated with basic semen parameters but positively correlated with sperm head and midpiece defects. sORP positively correlated with sperm tail defects, immature sperm cells with excess residual cytoplasm, and SDF. In turn, raw ORP negatively correlated with sperm count but positively correlated with SDF and sORP. These findings indicate that (1) there is a relationship between male infertility, SDF, and OS in semen; (2) in infertile men, there is a clinically significant risk of SDF and OS irrespective of leukocytospermia; and (3) the assessment of SDF and oxidative stress should be independent of leukocytospermia.

Evaluation of selected semen parameters and biomarkers of male infertility - preliminary study

Background: Because the etiopathogenesis of male infertility is multifactorial our study was designed to clarify the relationship between standard semen parameters, testicular volume, levels of reproductive hormones and the fragmentation of sperm nuclear DNA (SDF). Methods: Patients (n = 130) were clustered as subjects: 1) with an abnormal volume (utrasonography) of at least one testis (<12 mL) or with a normal volume of testes and 2) with abnormal levels of at least one of the reproductive hormones (FSH, LH, PRL, TSH, total T - electrochemiluminescence method) or with normal hormonal profiles and 3) with high level of SDF (>30%), moderate (>15-30%) or low (≤15%) (sperm chromatin dispersion test). Results: In subjects with a decreased testicular volume and in subjects with abnormal levels of reproductive hormones, decreased basic semen parameters were found. Participants with abnormal testicular volume had a higher percentage of SDF and a higher level of FSH (Mann-Whitney U test). In turn, men with a high level of SDF had lower testicular volume and conventional sperm parameters than men with a low level of SDF (Kruskal-Wallis test). Conclusions: We showed that spermatogenesis disorders coexisted with decreased testicular volume and increased FSH levels. The disorders of spermatogenesis were manifested by reduced basic sperm characteristics and a high level of sperm nuclear DNA damage.

The Role of Seminal Oxidative Stress Scavenging System in the Pathogenesis of Sperm DNA Damage in Men Exposed and Not Exposed to Genital Heat Stress

Responding to the need for the verification of some experimental animal studies showing the involvement of oxidative stress in germ cell damage in the heat-induced testis, we investigated the possibility of a direct relationship between seminal oxidative stress markers (total antioxidant capacity, catalase activity, superoxide dismutase activity, and malondialdehyde concentration) and ejaculated sperm chromatin/DNA integrity (DNA fragmentation and chromatin condensation abnormalities) in distinct groups of men exposed and not exposed to prolonged scrotal hyperthermia. A statistical increase in the proportion of sperm with DNA fragmentation was observed in all the studied subgroups compared to the fertile men. In turn, the groups subjected to heat stress as professional drivers or infertile men with varicocele presented greater disturbances in the oxidative stress scavenging system than men not exposed to genital heat stress. Based on the comparative analysis of the studied parameters, we can conclude that alterations in the seminal oxidative stress scavenging system are directly engaged in the pathogenesis of ejaculated sperm DNA damage regardless of the intensity of the impact of thermal insult. To the best of our knowledge, this study, for the first time, revealed the co-existence of oxidative stress and sperm DNA damage in the semen of professional drivers.

The Negative Impact of Varicocele on Basic Semen Parameters, Sperm Nuclear DNA Dispersion and Oxidation-Reduction Potential in Semen

Since varicocele is so common in infertile men, this study intends to analyse the relationships between varicocele and conventional semen characteristics, sperm nuclear DNA dispersion and oxidation-reduction potential (ORP) in semen. Varicocele-positive and varicocele-negative infertile men (study groups) showed significantly lower standard sperm parameters and higher sperm DNA fragmentation (SDF) and ORP in semen than healthy volunteers and subjects with proven fertility (control groups). A lower proportion of low SDF levels (0–15% SDF) and higher incidence of high SDF levels (>30% SDF), as well as a higher prevalence of high ORP values (>1.37 mV/10⁶ sperm/mL), were found in the study groups vs. the control groups. Moreover, infertile men had significantly lower odds ratios (ORs) for low SDF levels and significantly higher ORs for high SDF levels and high ORP. SDF and ORP were negatively correlated with sperm number, morphology, motility and vitality. Furthermore, a significant positive correlation was found between SDF and ORP. The obtained results suggest that disorders of spermatogenesis may occur in varicocele-related infertility. These abnormalities are manifested not only by reduced standard semen parameters but also by decreased sperm DNA integrity and simultaneously increased oxidative stress in semen.

Male aging as a causative factor of detrimental changes in human conventional semen parameters and sperm DNA integrity

The effect of male aging on fertility potential is controversial and difficult to predict. The aim of our study was to determine the associations between age, basic semen parameters, and sperm DNA fragmentation (SDF). Comparison of four age-dependent groups (men ≤29 years, 30-35 years, 36-40 years, and >40 years) revealed a significant fall in the basic semen characteristics and sperm genomic integrity with age. Receiver operating characteristic (ROC) analysis confirmed that men >29 years had lower semen quality. In the group of men >29 years, the prevalence of men with abnormal semen parameters was higher, and these men had over a threefold higher odds ratio (OR) for abnormal semen parameters. Next, ROC analysis revealed that a threshold of 18% SDF was optimal for discriminating between men with normal and abnormal standard semen parameters. The prevalence of men with >18% SDF was higher in the group of men >29 years than in men ≤29 years. Older men had an almost twofold higher risk for >18% SDF than younger men. Our results suggest that age >29 years may be a causative factor of detrimental changes in semen quality, which may raise the risk for disorders of male fertility potential.

Seminal Plasma Analysis of Oxidative Stress in Different Genitourinary Topographical Regions Involved in Reproductive Tract Disorders Associated with Genital Heat Stress

The pathophysiological mechanisms responsible for male subfertility/infertility caused by or complicated by genital heat stress remains unclear in many respects. Because seminal plasma creates the environment for the proper functioning of spermatozoa, in this study, we verified the associations among standard spermiograms, seminal biochemical parameters (neutral alpha-glucosidase, fructose, and citric acid) and oxidative stress markers (total antioxidant capacity, catalase activity, superoxide dismutase activity, and malondialdehyde concentration) in distinct entities associated with male infertility with and without long-time exposure to local hyperthermia. We demonstrated that men exposed to prolonged environmental or clinically recognized local heat stress in adulthood may suffer from dysregulation of seminal antioxidant components, which can be directly associated with epididymal and prostate function. The comparative analysis of the studied parameters showed numerous correlations among all biochemical parameters (particularly neutral alpha-glucosidase) with low standard semen quality in almost all the investigated infertile groups. In light of the data obtained in this originally designed study, we conclude that more attention should be paid to the epididymis and accessory gland function in subfertile and infertile men exposed to genital heat stress, especially in the context of novel treatment algorithms (targeted therapies).

Psychiatric and neurocognitive consequences of endogenous hypercortisolism

Psychiatric and neurocognitive symptoms due to hypercortisolism were already described by Harvey Cushing in his original paper on patients with Cushing's syndrome (CS). Nowadays, it is well known that psychiatric and cognitive complaints are two of the most common, and most distressing, symptoms in patients with CS. Psychiatric symptoms are indeed a major clinical manifestation of CS. The most commonly observed psychiatric conditions are depression and anxiety, whilst mania and psychosis are less common. Several domains of cognitive function are impaired at diagnosis, including episodic and working memory, executive function and attention. Following treatment, one-fourth of the patients still experience depressed mood, and the cognitive impairments are only partially restored. Consequently, quality of life in patients with CS is severely and persistently affected. Neuroimaging studies have also illustrated the deleterious effects of hypercortisolism on the brain by demonstrating reduced grey matter volumes and cortical thickness, altered resting-state functional responses and during cognitive tasks, as well as widespread reduced white matter integrity, especially in structures important for cognitive function and emotional processing, both before and after successful abrogation of hypercortisolism. In this paper, we summarize the current knowledge on the psychiatric and neurocognitive consequences of hypercortisolism in patients with CS, both before, and after successful treatment. In addition, we review the structural and functional brain abnormalities associated with hypercortisolism and discuss the influence of these factors on quality of life.

The higher risk for sperm DNA damage in infertile men

OBJECTIVES

Supplementary assays are needed for determination of relationships between sperm biomarkers and fertility potential. Therefore, our research was designed to determine the extent of sperm DNA fragmentation (SDF) and establish a discriminating threshold of SDF for fertility potential.

MATERIAL AND METHODS

Semen characteristics were evaluated according to World Health Organization recommendations, and SDF was assessed by sperm chromatin dispersion test on ejaculated spermatozoa from infertile and healthy normozoospermic men.

RESULTS

A higher proportion of SDF was noted in infertile men (median 23.00%) than normozoospermic (median 14.00%). Significantly less subjects (17.03%) with low SDF level (≤ 15%) and more (35.17%) with high SDF level ( > 30%) were found for the infertile group vs the normooospermic (57.90% and 5.26%, respectively). Infertile group had significantly lower odds ratio (OR) for having a low SDF level (OR: 0.1493) and higher OR for having a high SDF level (OR: 9.7627). Receiver operating characteristic analysis [area under curve (AUC) = 0.785] revealed that 20% SDF is predictive value for discriminating between infertile and normozoospermic subjects. SDF was negatively correlated with the sperm number, morphology, progressive motility and vitality but positively with the teratozoospermia index.

CONCLUSIONS

Our study demonstrates: (1) a significant difference in the extent of SDF and in the risk for having damaged sperm DNA between infertile and normozoospermic men, (2) > 20% SDF has negative predictive value for fertility potential, (3) coexistence of abnormal standard sperm parameters with sperm chromatin damages. Therefore, SDF should be considered as a highly valuable indicator of male fertility potential.

Relationship between sperm morphology and sperm DNA dispersion

Background

The pathogenesis of teratozoospermia (<4% morphologically normal sperm cells) and the relationship between sperm morphological abnormalities and abnormal sperm nuclear DNA fragmentation, which are considered indicators of male fertility, have not been elucidated. Our research was designed to determine the prevalence of different sperm DNA fragmentation (SDF) levels in men with teratozoospermia and to establish a discriminating threshold value for SDF in assessing sperm morphology.

Methods

Basic semen characteristics and detailed sperm morphological analysis (head, neck, midpiece, and tail defects and excess residual cytoplasm) (WHO, 2010), and the nuclear sperm DNA dispersion test were performed on semen samples obtained from 523 men with teratozoospermia (n=296) and those without teratozoospermia (n=227).

Results

Subjects with abnormal sperm morphology had not only lower results for standard sperm characteristics, including detailed sperm morphological abnormalities, but also a higher proportion of sperm cells with SDF vs. men with normal sperm morphology. Moreover, significantly fewer subjects with low SDF levels (≤15%), more subjects with high SDF levels (>30%) and a higher odds ratio (OR) for having high SDF levels were found in the group of men with teratozoospermia vs. men without teratozoospermia. However, the receiving operating characteristic (ROC) curve analysis indicated that a SDF >18% was a significant negative predictive value to distinguish between men with normal sperm morphology or men with abnormal sperm morphology. The optimal area under the ROC curve (AUC) was 0.746. In the group of men with teratozoospermia, a higher incidence of men with >18% SDF and a higher OR for having >18% SDF were observed. SDF negatively correlated with sperm number, morphologically normal sperm cells, sperm motility and sperm vitality but positively correlated with the teratozoospermia index (TZI) and detailed sperm morphological abnormalities.

Conclusions

The obtained findings demonstrated that: (I) detailed sperm structural defects coexist with abnormal nuclear sperm DNA dispersion, (II) men with teratozoospermia may have a higher risk for sperm DNA damage, (III) the calculated optimal SDF value of 18% measured by the DNA sperm dispersion test is the best criterion to predict normal and abnormal sperm morphology.

Age-related changes in human sperm DNA integrity

Abnormal standard semen characteristics and reduced sperm chromatin maturity can appear with increasing male age. However, the influence of paternal age on semen parameters is still controversial. Therefore, this study was designed to estimate the influence of paternal age not only on conventional semen characteristics but also on sperm DNA integrity. This research was carried out on ejaculated sperm cells obtained from men (n = 1124) aged ≥40 y and <40 y. Our data revealed a decreased semen volume and an increased percentage of DFI (sperm DNA fragmentation index) in older men compared to younger men in the entire study cohort, in men with normozoospermia and in men with abnormal semen parameters. Moreover, there was a higher incidence of sperm DNA damage (>10% DFI, low fertility potential) in the groups of men aged ≥40 y than in the groups of men aged <40 y. Older men had over twice the odds ratio for high sperm DNA damage as younger men. Our findings suggest a detrimental effect of advanced paternal age on sperm chromatin integrity. The data show that the evaluation of sperm DNA has greater clinical utility than standard semen analysis in case of male fertility potential assessment.

The impact of sedentary work on sperm nuclear DNA integrity

INTRODUCTION

Contemporary professional jobs that often enforce a sedentary lifestyle and are frequently associated with testicular overheat, deserve special attention with respect to male fertility potential. Interestingly, the harmful effect of testicular heat stress on sperm characteristics including nuclear DNA integrity was well characterized; however, the influence of sedentary work on sperm chromatin has not yet been documented. Therefore, our research was designed to examine the potential effects of sedentary work not only on conventional semen features but also on sperm nuclear DNA status.

MATERIALS AND METHODS

The study was carried out on ejaculated sperm cells obtained from men who spent ≥ 50% of their time at work (≥ 17.5 h per week) in a sedentary position (n = 152) and from men who spent < 50% of their time at work in a sedentary position (n = 102). Standard semen characteristics were assessed according to the WHO 2010 recommendations, while sperm nuclear DNA fragmentation (SDF) was evaluated using the Halosperm test.

RESULTS

There were no significant differences in the standard semen parameters between the study groups. The groups differed only in SDF parameter. The men who spent at least 50% of their work time in a sedentary position had a higher proportion of SDF than the men who spent < 50% of their time at work in a sedentary position (median value 21.00% vs. 16.50%, respectively). The incidence of low SDF levels (related to 0-15% sperm cells with abnormal DNA dispersion) was significantly lower (27.63% vs. 45.10%), the percentage of men with high SDF levels (related to > 30%) was significantly higher (30.92% vs. 16.67%) in group of men who spent at least 50% of their work time in a sedentary positon. Furthermore, these men were more than twice as likely to have not a low SDF level (OR: 0.4648) and had more than twice the risk of having a high SDF level (OR: 2.2381) than the men in less sedentary occupations.

CONCLUSIONS

Despite lack of association between sedentary work and conventional semen characteristics our study revealed detrimental effect of seated work on sperm nuclear DNA integrity. A sedentary job doubled the risk of high levels of sperm DNA damage. The pathomechanism could be related to testicular heat stress resulting in sperm chromatin remodelling failure during spermiogenesis. Therefore, it seems reasonable to simultaneously carry out routine seminological analyses and tests assessing sperm chromatin status while diagnosing male infertility.

The effect of human sperm chromatin maturity on ICSI outcomes

Because sperm chromatin may play a key role in reproductive success, we verify the associations between sperm chromatin abnormalities, embryo development and the ability to achieve pregnancy. The evaluation of sperm chromatin maturity using aniline blue (AB), chromomycin A3 (CMA3) and toluidine blue (TB) staining were carried out in group of males from infertile couples that underwent ICSI. Low levels of sperm chromatin abnormalities (< 16%) were found in most subjects (> 50%). A higher percentage of TB-positive sperm cells were discovered in the men from couples who achieved ≤ 50% fertilized oocytes compared to men who achieved > 50%. No significant differences were discovered by the applied tests between the men from couples who achieved ≤ 50% and those who achieved > 50% high-quality embryos on the 3rd or 5th day after fertilization, nor between the men from couples who achieved pregnancy and those who failed. The sperm chromatin maturity did not correlate with the ICSI results. However, the ROC analysis revealed a significant predictive value of TB-positive spermatozoa only for fertilization. Therefore, the TB assay can be considered as a useful test for the prediction of fertilization. Our findings suggest that the level of sperm chromatin abnormalities of the examined men was not clinically significant. No found associations between sperm chromatin maturity and embryo development and the ability to achieve pregnancy. We could not exclude the effects of the repairing processes in the fertilized oocyte. The use of complementary tests that verify the status of the sperm chromatin seems justified.

Photoswitchable transition metal complexes with azobenzene-functionalized imine-based ligands: structural and kinetic analysis

We report on the characterization of two imine type ligands containing photoresponsive azobenzene units as side groups and their transition metal ions complexes.

Bacterial Contamination of Boar Semen and its Relationship to Sperm Quality Preserved in Commercial Extender Containing Gentamicin Sulfate

This study was designed to determine the degree and type of bacterial contamination in boar semen (79 ejaculates from Large White and Landrace boars) and its consequences for sperm quality during storage (27 extended semen samples, 16°C for five days) under practical conditions of artificial insemination (AI). The results revealed the presence of aerobic bacteria in 99% of the ejaculates (from 80 to 370 ×106 colony-forming units/mL). Most of the ejaculates contained two or three bacterial contaminants, while the Staphylococcus, Streptococcus, and Pseudomonas bacterial genera were most frequently isolated. Also detected were Enterobacter spp., Bacillus spp., Proteus spp., Escherichia coli, P. fluorescens, and P. aeruginosa. In general, the growth of certain bacterial types isolated prior to semen processing (Enterobacter spp., E. coli, P. fluorescens, and P. aeruginosa) was not discovered on different days of storage, but fluctuations (with a tendency towards increases) were found in the frequencies of Bacillus spp., Pseudomonas spp., and Staphylococcus spp. isolates up to the end of storage. Semen preserved for five days exhibited decreases in sperm motility and increases in the average number of total aerobic bacteria; this was associated with sperm agglutination, plasma membrane disruption, and acrosome damage. We inferred that, due to the different degrees and types of bacterial contaminants in the boar ejaculates, the inhibitory activity of some antimicrobial agents used in swine extenders (such as gentamicin sulfate) may be limited. Because such agents can contribute to the overgrowth of certain aerobic bacteria and a reduction in the quality of stored semen, procedures with high standards of hygiene and microbiological control should be used when processing boar semen.

Organic cation/carnitine transporter OCTN2 (SLC22A5) -207C>G (rs2631367) polymorphism is not associated with male infertility

Carnitine is an important factor in the initiation of progressive sperm motility and end stage of sperm maturation. The compound is transported by an organic cation/carnitine transporter (OCTN2), which is expressed in the male reproductive system. OCTN2 is encoded by SLC22A5 gene with proven -207C>G functional polymorphism. The aim of the case-control study was to investigate a potential association between the -207C>G SLC22A5 polymorphism and male infertility. The -207C>G SLC22A5 polymorphism was determined by means of TaqMan assay in 206 infertile Caucasian males and 256 ethnically matched controls. Besides genotyping study, sperm mitochondrial function was assessed using NADH-dependent NBT assay. The distribution of SLC22A5 genotypes in infertile men was as follows: CC - 29.6%, CG - 53.9%, GG - 16.5% and in fertile men: CC - 32.0%, CG - 50.0%, GG - 18.0%, and was comparable in both evaluated groups. Likewise, the studied polymorphism did not affect sperm mitochondrial function. The results of the current study demonstrated that -207C>G polymorphism of the SLC22A5 gene is not associated with male infertility.

Sperm mitochondria diaphorase activity--a gene mapping study of recombinant inbred strains of mice

In order to study the genetic control of semen quality parameters, we derived a set of recombinant inbred (RI) mice from crosses between two inbred strains, KE and CBA/Kw, which differ significantly in gamete quality and fertility parameters. In this work, we used male mice from the two parental strains and from ten RI strains to map genes controlling quantitative traits such as sperm mitochondrial diaphorase activity, and assessed the correlation between this trait, sperm motility and in vivo fertilization efficiency. We analyzed sperm mitochondrial dehydrogenase (diaphorase) activity (NADH-dependent NBT assay) cytochemically by means of computerized image densitometry and obtained values for four parameters: 1) integrated optical density (IOD) for all pixels of the midpiece, 2) mean optical density (MOD) for the midpiece pixels, 3) length of sperm midpiece and 4) area of sperm midpiece. Polymorphic microsatellite marker profiles were prepared for 20 mouse chromosomes in the ten RI strains. We used Map Manager QTX software to correlate the strain distribution patterns (SDPs) of the four measured parameters with the SDPs of the analyzed markers. Hypothetical genes modifying diaphorase activity were mapped to chromosomal region 19q43-19q47, containing, for example, Poll, Sfxn2, Cyp17a1 and Usmg5 genes. Chromosomal regions 18q44 and 18q49-18q80 also showed correlation with the SDPs of diaphorase activity. Katnal2, Me2 and StARD6 candidate genes were proposed from this region. Diaphorase activity in the mouse sperm midpiece did not correlate with in vivo fertilization efficiency, but was negatively correlated with the linearity and straightness of sperm movement.

Flow cytometry application in the assessment of sperm DNA integrity of men with asthenozoospermia

Sperm genomic integrity and ultrastructural features of ejaculated spermatozoa contributing to the assessment of gamete fertility potential in patients with asthenozoospermia are discussed. The proportion of TUNEL-positive cells was significantly higher in the semen of patients with low sperm motility (n=40; p<0.01) as compared to men with normal sperm motility (n=54). Sperm DNA fragmentation negatively correlated (n=94) with sperm motility, sperm concentration, and integrity of the sperm cellular membrane (HOS-test). Two categories of patients were distinguished: (1) patients (23 out of 94 subjects) with < or = 4% of TUNEL-positive cells and (2) patients (71 subjects) with 4% of TUNEL-positive cells. A significant difference was noted in the sperm motility and HOS-test results between patients from both groups. Large numbers of immature spermatozoa with extensive cytoplasmic retention, ultrastructural chromatin and midpiece abnormalities, and conglomerates containing sperm fragments were present more frequently in the semen of asthenozoospermic subjects with >4% of TUNEL-positive sperm cells. Low sperm motility seems to be accompanied by serious defects of gamete chromatin expressed as diminished sperm genomic integrity and abnormal DNA condensation and by defects of sperm midpiece. These abnormalities may reflect developmental failure during the spermatogenic remodeling process. The DNA fragmentation test may be considered as an additional assay for the evaluation of spermatozoa beside standard analysis and taken together with electron microscopy may help to determine the actual number of "healthy" spermatozoa thereby playing an important role during diagnosis and treatment of male infertility.

Evaluation of sperm genomic integrity of normozoospermic men: a prospective study

The objective of our study was to evaluate the incidence of spermatozoa with nuclear DNA strand breaks in patients with normal routine sperm parameters (26 subjects). Sperm DNA fragmentation was measured using TUNEL test assessed in flow cytometer. Variable percentages of sperm with damaged DNA (9.42 +/- 7.68%; range: 2-36) were found. Two categories of patients were distinguished: (1) patients (8 out of 26 subjects) with < or = 4% of TUNEL-positive sperm and (2) patients (18 out of 26 subjects) with > 4% of TUNEL-positive sperm. A significantly lower percentage of normal sperm forms was found in patients with > 4% of TUNEL-positive sperm than in patients with < or = 4% of TUNEL-positive sperm. Moreover, a significant negative correlation (r(s) = -0.50) was noted only between a proportion of normal sperm forms and a proportion of TUNEL-positive spermatozoa. In electron microscope, a large number of spermatozoa with immature chromatin was observed more frequently in subjects with > 4% of TUNEL-positive cells (11 out of 18 subjects). Our results suggest that in some patients with normal routine sperm parameters, DNA fragmentation may be associated with poor sperm morphology. The diminished sperm genomic integrity may result from molecular disturbances in nuclear remodeling process during spermiogenesis. TUNEL assay is a screening tool that may help to discriminate between fertile and infertile men and may help to predict successful in vitro fertilization.

Diagnostic evaluation of oxidoreductive capability of sperm mitochondria

In the present paper, morphological and functional features of human sperm midpiece, contributing to the assessment of sperm fertility potential, have been described. The NADH-dependent NBT screening assay was used to identify and visualise: 1/ morphological defects of sperm midpiece, 2/ immature sperm forms with extensive cytoplasmic retention, reflecting developmental failure in spermatogenic remodelling process, 3/ cytoplasmic sperm conglomerates, related to apoptotic bodies and 4/ sperm NADH-dependent oxidoreductase system at the mitochondrial level, related to the reaction intensity. The used assay is an adequate marker of sperm mitochondrial activity and sperm maturity. It can also help discover sperm defects that result in asthenozoospermia and can be used as an additional indicator in the evaluation of the sperm midpiece, as well as in routine morphological examination of spermatozoa, having a considerable predictive value for in vivo and in vitro fertilization.

Aging process of epithelial cells of the rat prostate lateral lobe in experimental hyperprolactinemia induced by haloperidol

The aim of the study was to examine the influence of hyperprolactinemia, induced by haloperidol (HAL) on age related morphology and function changes of epithelial cells in rat prostate lateral lobe. The study was performed on sexually mature male rats. Serum concentrations of prolactin (PRL) and testosterone (T) were measured. Tissue sections were evaluated with light and electron microscopy. Immunohistochemical reactions for Anti-Proliferating Cell Nuclear Antigen (PCNA) were performed. In rats of the experimental group, the mean concentration of: PRL was more than twice higher, whereas T concentration was almost twice lower than that in the control group. Light microscopy visualized the following: hypertrophy and epithelium hyperplasia of the glandular ducts, associated with increased PCNA expression. Electron microscopy revealed changes in columnar epithelial cells, concerning organelles, engaged in protein synthesis and secretion.

Germ cells with nuclear DNA fragmentation related to apoptotic cells in rat testis in experimental hyperprolactinemia induced by metoclopramide

The cells with nuclear DNA fragmentation related to apoptosis were detected by TUNEL technique in the seminiferous epithelium of control rats and of rats with experimental hyperprolactinemia induced by metoclopramide. The percentage of convoluted tubules with apoptotic cells and the number of apoptotic cells (predominantly spermatogonia and spermatocytes) was increased in the experimental group. The results indicated stage-specific germ cell apoptosis. In the experimental group, apoptotic cells were most evident at early (I-IV), middle (VII-VIII) and late (XII-XIV) stages of the seminiferous epithelium cycle, as revealed by light and electron microscopy. We suggest that a decreased concentration of testosterone and an increased concentration of prolactin could disturb spermatogenesis and contribute to the intensive apoptosis of germ cells in rats with hyperprolactinemia. Sertoli cells which have receptors for testosterone and prolactin and play an important role in spermatogenesis and in the initiation of apoptosis in seminiferous epithelium, could mediate such an influence of both hormones.

Computerized analysis of cytochemical reactions for dehydrogenases and oxygraphic studies as methods to evaluate the function of the mitochondrial sheath in rat spermatozoa

Cytochemical reactions for mitochondrial NADH-dependent dehydrogenases (diaphorase/NADH which is related to flavoprotein), NAD-dependent dehydrogenases (isocitrate, malate) and succinate dehydrogenase were carried out in rat spermatozoa. In addition to a morphological evaluation, the intensity of the reactions was assessed using a computer image analysing system (Quantimet 600 S). The intensity of the reactions was examined in sperm midpieces by measuring integrated optical density (IOD) and mean optical density (MOD). The activity of mitochondrial respiratory chain complexes was also analysed using the polarographic method. In the population of spermatozoa studied, all whole spermatozoa midpieces were completely filled with formazans, the product of the cytochemical reaction. These morphological findings corresponded to the values obtained for IOD and MOD for the given enzymes. In the oxygraphic studies, the spermatozoa demonstrated consumption of oxygen in the presence of substrates for I, II and IV complexes and their mitochondria revealed normal integrity and sensitivity to the substrates and inhibitors. However, the oxygraphic studies revealed differences between the sperm and somatic cells. These differences concerned the stimulation of pyruvate oxidation by malate, the lack of an effect of malonic acid on phenazine methosulphate (an acceptor of electrons) oxidation and the lack of an effect of cytochrome c on ascorbate oxidation. The cytochemical method, together with densitometric measurements, enables: (1) the reaction intensity to be determined objectively; (2) subtle and dramatic differences in reaction intensity to be revealed between spermatozoa that do not differ under morphological evaluation of the intensity; (3) possible defects within the mitochondrial sheath to be located and assessed in a large number of spermatozoa. This method can be used as a screening method alongside the routine morphological examination of spermatozoa. On the other hand, the oxygraphic method in the inner membrane of mitochondria can reveal functional changes which are related to the action of respiratory chain complexes and display characteristic features of mitochondria energy metabolism. The methods used are complementary and allow the complex evaluation of mitochondria in spermatozoa. Both methods can be used in experimental and clinical studies.

Phospholipid content and lamellar structures in the epididymal epithelial cells of rats treated chronically with lead acetate [Pb(II)]

The electron-microscopic observations accomplished covered epididymal epithelial cells of rats receiving lead acetate for five times longer than the duration of one spermatogenesis. These cells were found to possess a large number of vacuoles and conglomerates containing plicated membranes or tightly packed myelin-like lamellar formations. Further observations also revealed the formation of lamellar structures in mitochondria, dilatation of cisternae in the Golgi apparatus, and increased phagocytosis of spermatozoa by epithelial cells. The presence of a large amount of membranous material correlated with the increased content of phospholipids in epididymal epithelial cells. It may be suggested that the presence of such a great quantity of lamellar structures in epididymal epithelial cells of rats treated chronically with lead is the result of several processes, including the augmented synthesis of membranes associated with encircling the deposits of lead, autophagy in the cells, as well as intensified phagocytosis of spermatozoa.

[Internal standardization of sperm morphology evaluated according to strict morphological criteria]

OBJECTIVE

To evaluate sperm morphology and find cut-off values for local andrology lab based on morphological strict criteria. To compare the results to WHO guidelines.

MATERIAL AND METHODS

Strict morphological criteria were applied to 300 sperm smears stained according to the Papanicolaou method. Specific sperm defects were described in details. The results were analyzed statistically.

RESULTS

The normal sperm morphology was found in 18.54% of cases, which is less than the cut-off value suggested in the WHO guidelines. The lab cut-off value aimed by the 25th percentile was 8%.

CONCLUSION

Sperm morphology requires broader multi-center standardization to enable compatible exchange of morphological data and find predictive factors of sperm fertilizing potential.

[Changes in sperm mitochondria in patients with asthenozoospermia]

OBJECTIVE

To evaluate functional and ultrastructural alterations of the spermatozoa midpieces in patients with asthenozoospermia and to find a correlation between the damage of the midpieces and loss of sperm motility.

MATERIAL AND METHODS

Routine, morphological assessment of the midpieces stained according to the Papanicolaou method, cytochemical study of the mitochondrial activity using reaction for the diaphorase/ NADH according to the Piasecka method and electron-microscopic investigation of the midpiece structures were performed.

RESULTS

The cytochemical reaction for diaphorase/NADH revealed disorders of the mitochondrial activity and subtle and drastic malformations in the spermatozoa midpieces. The unusually thickened midpieces contained the supernumerary mitochondria. In patients with severe asthenozoospermia, the damage of the accessory fibres and axonemal complex located in the midpiece, were obtained also.

CONCLUSION

This study indicates that mitochondrial defects are one of the causes that may account for loss of sperm motility in the population of patients.

The ultrastructure of the testis in rats after long-term treatment with lead acetate

Studies were performed to investigate the influence of long-term lead acetate treatment on morphology of rat testis. No marked changes were observed by means of light microscopy. At all stages (I-XIV) of the seminiferous epithelium cycle, all generations and layers of spermatogenic cells were present. Electron-microscopic studies did not reveal any ultrastructural changes neither in seminiferous epithelium nor in Sertoli cells. In Leydig cells also, no ultra-structural abnormalities were visible. Macrophages of testicular interstitial tissue contained electron-dense inclusions, usually located inside phagolisosome-like vacuoles. X-ray micro-analysis revealed that the inclusions contained lead.

[Influence of chronic use of lead ions on rat spermatozoa]

The aim of the paper has been to establish the manner, in which the lead damages spermatozoa, and what role in this process is played by epithelial cells of epididymis, responsible for maturation and survival of spermatozoa in that organ. The studies were carried out on sexually mature male rats, which were given to drink lead acetate (II), for 9 months. Studies in vitro were also performed on isolated, from epididymis, spermatozoa of rats untreated with lead, but incubated in milieu having high concentration of ions of that element. A number of research techniques were employed: morphologic examinations of testes and epididymidis, with stages of spermic epithelium and epididymal zones being taken into consideration; microscopic-electron studies of cells in epididymal duct wall and spermatozoa from duct lumen; X-ray microanalysis determining the presence and the types of elements on ultrathin specimens of epididymal cells and in spermatozoa; histochemical examinations for oxidoreductase of spermatozoa. Lead deposits were found in cells of the epididymal duct and lumen. The most of such deposits were revealed in epithelial cells, through which substances from the blood vessels are transported to the duct lumen-to spermatozoa. That gives rise to the possibility of damaging spermatozoa, which had been verified by microscopic-electron and histochemical examinations of spermatozoa. The vitro studies disclosed the ability of lead to penetrate spermatozoa, particularly the midpiece. Very important is the conclusion highlighting that the presence of lead deposits in epithelial cells and in the lumen of epididymal duct supports the possibility of excreting this element from the organism of mammals with the semen.

Evaluation of spermatozoa of the rat in hyperprolactinaemia induced by metoclopramide

Metoclopramide (MCP) in doses of 2.2 mg kg-1 body weight, being administered intraperitoneally to rats for 14 d, provokes a premature release of germ cells in the testes. The number of spermatozoa is reduced. In addition the spermatozoa exhibit defects of head and tail structures. After the administration of MCP for 14 d, followed by a 14-d break in applying the drug, the number of spermatozoa in the lumen of the epididymal duct continues to be low. Many spermatozoa are damaged. Only after a 66-d-break in MCP administration is the morphology of the seminiferous epithelium restored, and a large number of spermatozoa appear in the lumen of the epididymal duct.