Characterization of oxidative stress status by evaluation of reactive oxygen species levels in whole semen and isolated spermatozoa

Mechanisms of Male Reproductive Toxicity of Polybrominated Diphenyl Ethers

Polybrominated diphenyl ethers (PBDE) are a group of flame retardants used in a variety of artificial materials. Despite being phased out in most industrial countries, they remain in the environment and human tissues due to their persistence, lipophilicity, and bioaccumulation. Populational and experimental studies demonstrate the male reproductive toxicity of PBDEs including increased incidence of genital malformations (hypospadias and cryptorchidism), altered weight of testes and other reproductive tissues, altered testes histology and transcriptome, decreased sperm production and sperm quality, altered epigenetic regulation of developmental genes in spermatozoa, and altered secretion of reproductive hormones. A broad range of mechanistic hypotheses of PBDE reproductive toxicity has been suggested. Among these hypotheses, oxidative stress, the disruption of estrogenic signaling, and mitochondria disruption are affected by PBDE concentrations much higher than concentrations found in human tissues, making them unlikely links between exposures and adverse reproductive outcomes in the general population. Robust evidence suggests that at environmentally relevant doses, PBDEs and their metabolites may affect male reproductive health via mechanisms including AR antagonism and the disruption of a complex network of metabolic signaling.

Scientific landscape of oxidative stress in male reproductive research: A scientometric study

Unraveling the role of reactive oxygen species and associated oxidative stress (OS) in male reproduction is one of the key areas of male reproductive research. This article illustrates the scientific landscape of OS in male reproductive research over the past several decades (1941-2018) using a scientometric approach. Scientometric data (articles per year, authors, affiliations, journals, and countries) on OS related to male reproduction were retrieved from the Scopus database and analyzed for each decade. Our analysis revealed an increasing trend in OS-based male reproductive research from 1941 to 2018 with a steep raise in publications and research collaborations starting from the period 1991-2000 (R² = 0.81). Semen abnormalities and varicocele were the major areas investigated in relation to OS with the highest positive trend in publications from the time interval 1981-1990 to 2011-2018. Analysis of publications based on OS assessment techniques revealed chemiluminescence (n = 180) and evaluation of antioxidants (n = 300) as the most widely used direct and indirect tests, respectively. Furthermore, prognostic/diagnostic studies on OS evaluation increased significantly over the time. Our analysis highlights the evolution of OS in male reproductive research and its emergence as an important prognostic and diagnostic tool in the evaluation of male infertility.

Which agent should be used to reduce ischemia-reperfusion injury after testicular torsion: a comparative animal experiment

INTRODUCTION

Testicular torsion is an acute urological emergency that causes severe damage of testis. In order to prevent testicular damage, early diagnosis and surgical intervention is essential. Also pain management in both pre-operative and postoperative periods remains a challenging entity.

OBJECTIVE

In this study, we aimed to determine the possible positive effects of three different analgesics (ibuprofen, metamizole, and paracetamol), which are widely used in clinical practice on testicular tissue, in addition to pain control.

STUDY DESIGN

Forty prepubertal rats (180-210 g) were divided into five experimental groups. Group 1 was sham group in which the left testis was brought out through a scrotal incision and then replaced in the scrotum without torsion. Group 2 was control group (only 0.9% NaCl was applied). Also in group 3, paracetamol, in group 4, ibuprofen, and in group 5, metamizole sodium was applied 1 h after the torsion. Torsion duration was planned as 4 h for all groups.

RESULTS

In the biochemical evaluation, malondialdehyde (MDA), myeloperoxidase (MPO), and total nitrate (NO) levels were measured in the testicular tissue. All groups were compared with group 2 (control group). In group 3, although the MDA level was lower and the MPO level was found to be higher, these were not statistically significant. In group 4, the NO level was low but statistically significant. Histological findings were evaluated due to Cosentino's classification, and the scores of group 4 were better than all groups.

DISCUSSION

In this study, severe damage was observed at the end of torsion period of 4 h. This is in line with previous published data. The beneficial effects of all three drugs have been observed.

CONCLUSIONS

Biochemical results did not clearly highlight any agents. According to pathology results, metamizole was better than paracetamol and the most ideal analgesic preparation was observed as ibuprofen.

Antioxidants: Terminology, Methods, and Future Considerations

Unreliable terminology and incompatible units of antioxidant activity/concentration expression lead to the failure of antioxidant clinical trials, ambiguity of conclusions about the effect of a chosen therapy in medicine and evaluation of food quality, diet, difficulties using information in monitoring the training process in sports, etc. Many different terms (antiradical activity, antioxidant activity, antioxidant capacity, antioxidant power, antioxidant ability) and methods: Trolox equivalent capacity assay (TEAC), Ferric Reducing Antioxidant Power assay (FRAP), Cupric Reducing Antioxidant Capacity assay (CUPRAC), antioxidative activity assay (ABTS), the oxygen radical absorbance capacity (ORAC), and different options of electrochemical ones) proposed for the determination of antioxidants are described. Possible approaches to the development of this field of science and practice are considered.

Curcumin Inhibits The Adverse Effects of Sodium Arsenite in Mouse Epididymal Sperm

Background

The aim of this study was to investigate the effects of curcumin on epididy- mal sperm parameters in adult male Navel Medical Research Institute (NMRI) mice ex- posed to sodium arsenite.

Materials and Methods

In this experimental study, we divided the animals into four groups: control, sodium arsenite (5 mg/kg), curcumin (100 mg/kg) and curcumin+sodium arsenite. Exposures were performed by intraperitoneal injections for a 5-week period. After the exposure period, we recorded the animals’ body and left testes weights. The left caudal epididymis was used to count the sperm number and analyze motility, viability, morphological abnormalities, acrosome reaction, DNA integrity, and histone-protamine replacement in the spermatozoa. One-way analysis of variance (ANOVA) followed by the Tukey’s test was used to assess the statistical significance of the data with SPSS 16.0. P<0.05 was considered significant.

Results

Mice exposed to sodium arsenite showed a significant decrease in the num- ber, motility, viability, normal sperm morphology and acrosome integrity of spermato- zoa compared to the control group. In the curcumin+sodium arsenite group, curcumin significantly reversed these adverse effects to the point where they approximated the control. In addition, the application of curcumin alone had no significant difference in these parameters compared to the control and curcumin+sodium arsenite groups. However, we observed no significant differences in the body and the testis weight as well as the DNA integrity and histone-protamine replacement in the spermatozoa of the four groups.

Conclusion

Curcumin compensated for the toxic effects of sodium arsenite on a number of sperm parameters in adult mice.

Reactive Oxygen Species (ROS) in human semen: determination of a reference range

PURPOSE

High levels of reactive oxygen species (ROS) are a leading cause of male factor infertility. Measurement of ROS has been hampered by a lack of standardisation and confounding variables including choice of controls and sample selection. This study aimed to determine a reference range for ROS in human semen.

METHODS

Semen samples were obtained from men attending for routine semen analysis who gave informed consent for the study. Samples were assigned groups: Group 1 (N = 94) normal semen parameters, no leucocytospermia; Group 2 (N = 100) abnormal semen parameters, no leucocytospermia; Group 3 (N = 41) any semen parameters with leucocytospermia. ROS levels were assayed in fresh neat semen using a chemiluminescence assay measured in a single tube luminometer. Data are reported in relative light units (RLU)/sec/10(6) sperm

RESULTS

ROS levels were significantly different between Groups 1, 2 and 3 (19.75 ± 8.12, 95.03 ± 33.63, 890.17 ± 310.23 RLU/sec/10(6) sperm respectively; p < 0.001). Group 3 gave the highest value confirming this group as the optimum choice for positive controls. The reference range < 24.1 RLU/sec/10(6) sperm was determined by ROC analysis that differentiates a reference population (Group 1) from a positive control group (Group 3), optimising the sensitivity and specificity (80.5 and 87.2% respectively) of the test.

CONCLUSIONS

We have determined a reference range for ROS in human semen and identified a patient population that falls outside the normal range. This simple, cost effective assay can be incorporated into routine diagnostic testing to aid in the diagnosis of male infertility, especially with regard to unexplained infertility.

Low amounts of mitochondrial reactive oxygen species define human sperm quality

We have applied the mitochondria-specific superoxide fluorescent probe MitoSOX Red (MitoSOX) to detect mitochondria-specific reactive oxygen species (mROS) production in human sperm samples using flow cytometry. We show that human ejaculates are heterogeneous in terms of mROS production, with three subpopulations clearly detectable, comprising sperm that produce increasing amounts of mROS (MitoSOX−, MitoSOX+, and MitoSOX++). The sperm subpopulation producing the lowest amount of mROS represented the most functional subset of male gametes within the ejaculate, as it was correlated with the highest amount of live and non-apoptotic sperm and increased both in samples with better semen parameters and in samples processed by both density-gradient centrifugation and swim-up, both known to select for higher quality sperm. Importantly, the MitoSOX− subpopulation was clearly more prevalent in samples that gave rise to pregnancies following assisted reproduction. Our work, therefore, not only describe discreet human sperm heterogeneity at the mROS level but also suggests that mROS may represent a strategy to both evaluate sperm samples and isolate the most functional gametes for assisted reproduction.

Free Portuguese abstract

A Portuguese translation of this abstract is freely available athttp://www.reproduction-online.org/content/147/6/817/suppl/DC1

Relationship amongst teratozoospermia, seminal oxidative stress and male infertility

BACKGROUND

Spermatozoa morphology is an important and complex characteristic of the fertilization capacity of male germ cells. Morphological abnormalities have been observed to be accompanied by reactive oxygen species (ROS) overproduction and further damage to spermatozoa, ultimately leading to infertility. Therefore, this study aimed to examine the relationship between seminal ROS production and sperm morphology in infertile teratozoospermic patients as well as in healthy men of proven and unproven fertility.

METHODS

Semen samples were collected from 79 patients classified as teratozoospermic and 56 healthy donors (control). Standard semen analysis was performed and spermatozoa morphology was assessed according to the WHO 2010 guidelines. Seminal ROS was measured by chemiluminescence assay. Receiver operating characteristic (ROC) curves were generated, and sensitivity, specificity, cutoff value and area under curve (AUC) were determined.

RESULTS

Sperm morphology was significantly poor in the Teratozoospermic Group compared with the 3 Donor Groups (P < 0.05). Significantly higher levels of ROS (RLU/sec/10⁶ sperm) were seen in the Teratozoospermic group (145.4 (41.5; 555.4) compared to the Donor Groups: All Donors (64.8 (21.1; 198.2), Proven Donors (58.8 (14.2; 79.2) and Proven Donors < 2 years (58.8 (14.2; 79.2) (P < 0.05). ROS correlated negatively with sperm concentration in the All Donor group (r = -0.354; P = 0.021) as well as in the Teratozospermic group (r -0.356; P = 0.002). Using ROC analysis, we established the cutoff values for concentration, morphology and ROS.

CONCLUSIONS

The incidence of teratozoospermia may be directly related to the overproduction of seminal ROS. Therefore, besides sperm concentration and motility, spermatozoa morphology should receive an equally important consideration in the overall assessment of male fertility.

Assessment of oxidative stress in sperm and semen

The chemiluminescence method is the most commonly employed technique as a direct measurement of reactive oxygen species (ROS) generation by spermatozoa. This assay is capable of quantifying both intracellular and extracellular ROS. Moreover, the use of various probes allows for differentiation between superoxide and hydrogen peroxide production by spermatozoa. When the total antioxidant reserves are overwhelmed by excessive production of ROS, it results in oxidative stress. Therefore correct measurement of both ROS and total antioxidant capacity (TAC) is essential in the assessment of oxidative stress in sperm and semen. This chapter describes the methodological approach for measuring seminal oxidative stress through the use of chemiluminescence assay for accurate measurement of ROS and the colorimetric assay for measurement of TAC.

Does high load of oxidants in human semen contribute to male factor infertility?

Basal generation of reactive oxygen species (ROS) was essential for male reproductive function, whereas high ROS levels may be linked to low quality of sperm and male infertility. We examined the associations between ROS levels in whole ejaculates and sperm quality among 1092 male factor infertility (MFI) patients and 50 donors with normal semen characteristics. ROS levels were significantly positively correlated with abnormal morphology rate, head defect, and sperm deformity index. Further, we investigated whether seminal plasma from MFI patients with high ROS levels affects sperm motility from donors with normal semen characteristics. After cross-culturing fresh human sperm from donors possessing normal semen characteristics with seminal plasma from infertitle men, sperm motility was measured at different ROS levels. Seminal plasma from MFI patients significantly reduced motility of sperm and the reduction rate increased with increasing ROS levels in seminal plasma. On the other hand, we found MFI patients with the ROS levels in the lowest 25th percentile had similar ROS levels to donors with normal semen characteristics. Collectively, our observations lead to the hypothesis that oxidative stress plays a critical role in the development of MFI among those with high ROS levels, but not those with low ROS levels.

Impact of oxidative stress on male fertility - a review

Oxidative stress is a state related to increased cellular damage caused by oxygen and oxygen-derived free radicals known as reactive oxygen species (ROS). It is a serious condition, as ROS and their metabolites attack DNA, lipids and proteins, alter enzymatic systems and cell signalling pathways, producing irreparable alterations, cell death and necrosis. While small amounts of ROS have been shown to be required for several functions of spermatozoa, their excessive levels can negatively impact the quality of spermatozoa and impair their overall fertilising capacity. These questions have recently attracted the attention of the scientific community; however, research aimed at exploring the role of oxidative stress and antioxidants associated with male fertility is still at its initial stages. This review summarises the current facts available in this field and intends to stimulate interest in basic and clinical research, especially in the development of effective methods for the diagnosis and therapy of semen damage caused by oxidative stress.

N-acetylcysteine counteracts oxidative stress and prevents hCG-induced apoptosis in rat Leydig cells through down regulation of caspase-8 and JNK

We have earlier reported that following persistent stimulation with hCG, oxidative stress-induced apoptosis in rat Leydig cells was mainly achieved through the extrinsic pathway. In the present study, the role of N-acetylcysteine (NAC) in counteracting the oxidative stress and the mechanisms of inhibition of apoptosis under such conditions were investigated. NAC (1 mM) intervention with repeated hCG stimulation (50 ng/ml, four times, each with 30 min challenge) prevented the decline in Leydig cell viability and the rise in lipid peroxidation and reactive oxygen species. Simultaneously, the activities of the enzymes glutathione-S-transferase, catalase, superoxide dismutase and the intracellular glutathione and antioxidant capacity of the treated cells improved significantly. Apoptotic markers Fas, FasL, and caspase-8, up-regulated following repeated hCG exposure, were significantly down-regulated following NAC co-incubation. While Bcl-2 expression was fully restored, Bax and caspase-9 remained unchanged. NAC treatment induced down-regulation of upstream JNK/pJNK and down-stream caspase-3 in the target cells. Taken together, the above findings indicate that NAC counteracted the oxidative stress in Leydig cells induced as a result of repeated hCG stimulation, and inhibited apoptosis by mainly regulating the extrinsic and JNK pathways of metazoan apoptosis.

Adverse effects associated with persistent stimulation of Leydig cells with hCG in vitro

The detrimental effects of persistent stimulation with hCG were investigated in rat Leydig cells in vitro. Significant rise in lipid peroxidation and reactive oxygen species (ROS) with concomitant attenuation in the activities of antioxidant enzymes: superoxide dismutase, catalase, and glutathione-S-transferase was observed. Transcripts for catalase and superoxide dismutase were also depleted. Subsequent to each hCG challenge, the total antioxidant capacity in the target cells also declined significantly (P < 0.05). There was an increase in cell apoptosis (23%), which was associated with a rise in caspase-3 activity, PARP cleavage, and Fas, FasL, caspase-8 expression. While Bax and Caspase-9 expression remained unchanged, Bcl-2 demonstrated a marked decline. Taken together, the above data indicate that persistent hCG stimulation of Leydig cells induced adverse effects leading to oxidative stress and apoptosis which was channeled primarily through the extrinsic pathway.

Flow-sorted ram spermatozoa are highly susceptible to hydrogen peroxide damage but are protected by seminal plasma and catalase

To determine whether flow sorting increased the susceptibility of spermatozoa to reactive oxygen species (ROS), ram semen was either diluted with Tris medium (100 × 106 spermatozoa mL–1; D) or highly diluted (106 spermatozoa mL–1) before being centrifuged (DC) at 750g for 7.5 min at 21°C or flow-sorted (S) before cryopreservation. Thawed spermatozoa were resuspended in graded concentrations of hydrogen peroxide to induce oxidative stress. In Experiment 1, following exposure to 30 or 45 μM hydrogen peroxide (H2O2), the total motility (%) of DC (41.0 ± 7.3 or 25.7 ± 6.7, respectively) and S spermatozoa (33.8 ± 6.3 or 20.1 ± 6.3, respectively) was lower (P < 0.001) than that of D spermatozoa (58.7 ± 5.6 or 44.5 ± 6.7, respectively). In Experiment 2, supplementation of samples containing H2O2 with catalase (150 IU mL–1) or seminal plasma proteins (4 mg protein per 108 spermatozoa) negated oxidative stress, resulting in comparable values to samples receiving no H2O2in terms of the proportion of spermatozoa with stable plasmalemma (as determined using merocyanine-540 and Yo-Pro-1) in the D and S groups, the proportion of viable, acrosome-intact spermatozoa (as determined by fluorescein isothiocyanate and propidium iodide staining) in the D group and the motility of control (undiluted) and S spermatozoa. Neither H2O2 nor sperm type (i.e. D, DC or S) had any effect on intracellular concentrations of ROS. These results show that flow sorting increases the susceptibility of spermatozoa to ROS, but the inclusion of anti-oxidants or seminal plasma as part of the sorting protocol improves resistance to oxidative stress.

The measurement of reactive oxygen species in human neat semen and in suspended spermatozoa: a comparison

BACKGROUND

It is generally accepted that oxidative stress is an important factor in male infertility because it may impair the physiological function of spermatozoa at the molecular level. Nevertheless, although several approaches have been reported, the imbalance between production of reactive oxygen species (ROS) and activity of the antioxidant defense system in semen is difficult to investigate and remains poorly understood.

METHODS

This study compares measurement of ROS production in neat semen and in washed spermatozoa obtained from the same ejaculate, and suspended in phosphate buffered saline using exactly the same luminol-mediated chemiluminescence method. Ninety one samples were obtained from males of infertile couples and 34 from volunteers with proven fertility.

RESULTS

As expected, ROS levels were markedly lower in neat semen than in washed spermatozoa suspensions where seminal plasma with its potent antioxidant capacity was removed. In the cases of both neat semen and washed spermatozoa, ROS production was lowest in samples from normozoospermic males and highest in samples containing more than half million peroxidase-positive leukocytes per milliliter. For all samples, there was a significant positive correlation between ROS production by neat semen and that by washed spermatozoa suspension.

CONCLUSION

Measurement of ROS production in neat semen better reflects actual oxidative status because it detects only the overproduction of ROS which are not effectively scavenged by antioxidant capacity of seminal fluid. The results of our study show a good commutability of both measurements for identification of semen samples with high ROS production. The measurement in neat semen is even less time consuming and therefore easier to implement into laboratory routine.

Washing increases the susceptibility to exogenous oxidative stress in red deer spermatozoa

The effects of routine sperm work are often overlooked. We assessed the effect of washing cryopreserved epididymal spermatozoa from red deer (Cervus elaphus hispanicus, Helzheimer 1909). After thawing, epididymal samples (four stags) were diluted in TALP-HEPES. A split was left untouched, another was centrifuged (300 x g, 5 min) and resuspended, and a third was centrifuged and the supernatant substituted by fresh TALP-HEPES (washing). Each split was supplemented either with nothing, 1mM of the antioxidant Trolox, 100 microM of the oxidant Fe (with ascorbate), or both. The 3x4 treatments were incubated at 37 degrees C and assessed each hour up to 3h for motility (computer-aided sperm assessment) and viability/apoptosis plus mitochondrial status (YO-PRO-1, propidium iodide, Mitotracker Deep Red; flow cytometry). DNA damage at 4h was assessed using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay. Centrifugation alone affected neither sperm quality nor DNA, and the oxidant had no effect in control or centrifuged samples. Washed samples were not different than control, but oxidant decreased motility, mitochondrial status and viability, and altered the motility subpopulation pattern, being partially suppressed by Trolox. Spermatozoa with damaged DNA dramatically increased in the washed-oxidized sample (from 22.30+/-3.52% to 67.94+/-5.07%), but not when antioxidant was present. Although samples from different males behaved similarly, male-to-male variability was detected regarding susceptibility to oxidative damage after washing. We concluded that, although red deer thawed spermatozoa seemed resilient to centrifugation, the vulnerability to oxidative stress after washing makes it advisable to supplement manipulation media with antioxidants, especially taking into account male-to-male variability.

Markers of oxidative stress and sperm chromatin integrity

Oxidative stress (OS) is an imbalance between the amount of reactive oxygen species (ROS) produced and the ability of the antioxidants to scavenge these. OS has been established as a major etiological cause of male infertility. High levels of ROS are harmful and cause damage to sperm nuclear DNA. Evaluation of OS-related damage to spermatozoa is therefore highly relevant in assisted reproductive techniques (ART) such as intracytoplasmic sperm injection (ICSI). ICSI is an effective therapy for severe male factor infertility that bypasses the majority of reproductive tract deficiencies. Despite the controversial findings in the existing literature, there is now enough evidence to show that sperm DNA damage is detrimental to reproductive outcomes. In addition to impairment of fertility, such damage might increase the transmission of genetic diseases to the offspring. Standardization of protocols to assess ROS, antioxidant status, and DNA damage is very important for implementation of these tests in clinical practice. Estimation of seminal ROS levels and extent of sperm DNA damage, especially in an infertile male, may help develop new therapeutic strategies and improve the success of ART.

Physiologic and pathologic levels of reactive oxygen species in neat semen of infertile men

OBJECTIVE

To define physiologic levels of reactive oxygen species in infertile men and establish a cutoff value of reactive oxygen species level in neat semen with a high sensitivity and specificity to differentiate infertile men from fertile donors (controls).

DESIGN

Reactive oxygen species levels were measured in the neat semen samples (n = 51) from fertile donors and infertile patients (n = 54).

SETTING

Reproductive research laboratory at a tertiary care hospital.

PATIENT(S)

Infertile patients from male infertility clinic.

INTERVENTION(S)

Reactive oxygen species measurement in neat semen sample using luminol-based chemiluminescence method, receiver operating characteristic curves.

MAIN OUTCOME MEASURE(S)

Seminal reactive oxygen species levels, cutoff value, sensitivity and specificity, positive and negative predictive values.

RESULT(S)

The best cutoff value to distinguish between healthy fertile donors and infertile men was 0.0185 x 10(6) counted photons per minute/20 x 10(6) sperm. At this threshold, the specificity was 82% and the sensitivity was 78%. This value can be defined as basal reactive oxygen species level in infertile men.

CONCLUSION(S)

Reactive oxygen species levels in neat semen samples as measured by luminol-based chemiluminescence are a highly specific and sensitive test in the diagnosis of infertility. This test also may help clinicians treat patients with seminal oxidative stress.

Antioxidant therapy in male infertility

Although reports have suggested the benefit of antioxidant treatment of infertile men, many studies also show no effect. Most studies in the literature are not randomized, placebo controlled, or double blinded in design, which makes it difficult to differentiate regression toward the mean from true positive treatment effects. The small patient sample sizes and varying male populations also add to the difficulty in comparing studies. Pregnancy, the most relevant outcome parameter, is rarely reported. Ideally, patients would be selected based on oxidative stress levels, and improvement in these levels would be correlated to improvement in pregnancy rates. Until those studies are performed, the use of antioxidants for the treatment of male infertility remains empiric.

Efficiency assessment of a swift method to enhance substandard viability ram ejaculates

Semen availability in ram semen processing facilities is of great importance for the genetic improvement of sheep. Accordingly, any method that would increase sperm viability in low viability ejaculates could be useful. In this study, the possibility of a glass beads filtration method by estimating the beads total surface provided (TSP) for adhesion of spermatozoa, was evaluated. Initially, two different TSP (102 and 154 cm(2)) achieved by various sizes of beads (1500, 2000 and 3000 microm) were tested and no significant difference in sperm viability improvement was noticed for the same TSP by different beads (p > 0.05). Next optimization tests were performed in which three different funnels were used for filtration at a standard TSP (154 cm(2)). The pear-shaped funnel was found to be the most appropriate for filtration, as semen volume recovery and sperm viability improvement were more pronounced (p < 0.05). Finally, filtration tests were conducted with pear-shaped funnels with different TSP (102 and 154 cm(2)) obtained by the aforementioned beads sizes (1500, 2000 and 3000 microm) in equal aliquots. Total surface provided of 102 cm(2) proved to be the more appropriate for filtration than 154 cm(2), as shown by the significant improvement of sperm viability (p < 0.01) and the significantly higher filtrate semen volume (p < 0.05). In conclusion, ram sperm viability improvement by more than 20% of its initial value and semen volume recovery by more than 60%, along with the fact that the total filtration time did not exceed 6 min in any case, suggest that through further development this method could be successfully used during ram semen processing.

Protective effect of L-carnitine on testicular ischaemia-reperfusion injury in rats

Testicular torsion is a urological emergency referred to as 'acute scrotum', because inappropriate treatment can lead to male subfertility and infertility. A possible cause of testicular damage is the ischaemia-reperfusion (I/R) injury attributed to oxygen free radicals. L-carnitine, a vitamin-like antioxidant, plays a pivotal role in the maturation of spermatozoa within the reproductive tract. The aim of the present paper was to determine the protective effect of L-carnitine on testicular I/R-induced injury. Thirty-two male rats were divided into 4 groups (n = 8). Testicular torsion was created by rotating the right testis 720 degrees in a clockwise direction. Group 1: sham-operated control; group 2: ischaemia; group 3: I/R; group 4: ischaemia-L-carnitine treatment-reperfusion group. L-carnitine (500 mg kg(-1), intraperitoneally) was administered before 30 min of detorsion in Group 4. After torsion (5 h) and detorsion (5 h), bilateral orchidectomy was performed. The malondialdehyde (MDA) level was evaluated in testes. Histopathologically, Johnsen's spermatogenesis criteria and mean seminiferous tubule diameter (MSTD) measurements were used. Testicular MDA levels were higher in the torsion group compared to the sham-control group (p < 0.05). Detorsion (reperfusion) caused a further increase in MDA levels (p < 0.05). Pretreatment with L-carnitine prevented a further increase in MDA levels (p < 0.05). Histologically, torsion caused some separation among germinal cells in the seminiferous tubules, which became much more prominent in the I/R group but was attenuated with L-carnitine pretreatment. In conclusion, L-carnitine pretreatment may have a protective effect in experimental testicular torsion-detorsion model in rats by its well-known antioxidant potential.

Protective effects of ibuprofen on testicular torsion/detorsion-induced ischemia/reperfusion injury in rats

The aim of this study was to investigate the protective effect of ibuprofen on testicular torsion/detorsion-induced ischemia/reperfusion (I/R) injury. A total of 48 prepubertal male Wistar albino rats were divided into two models: early and late orchiectomy. Testicular torsion was created by rotating the right testis 720 degrees in a clockwise direction. The ischemia period was 5 h and orchiectomy was performed after 5 h of detorsion in the early orchiectomy model (EOM). In the late orchiectomy model (LOM), the ischemia period was 5 h and orchiectomy was performed after 7 days of detorsion. In the EOM, ibuprofen (70 mg/kg, po) was administrated only once, 40 min prior to detorsion. In the LOM, ibuprofen (70 mg/kg, po) was administered 40 min before detorsion, once daily for 7 days. Bilateral orchiectomy was performed in all groups to measure the tissue levels of malondialdehyde (MDA) and to microscopically investigate light and electrons. The presence of endothelial nitric oxide synthase (eNOS) activity was shown with immunohistochemical studies. Spermatogenesis and mean seminiferous tubule diameter (MSTD) were significantly decreased in ipsilateral and contralateral testis when both early and late I/R groups were compared to the sham groups. Furthermore, ibuprofen-treated animals showed an improved histological appearance in both models of testicular torsion. Ibuprofen treatment prevented lipid peroxidation resulting in decreased MDA accumulation in the testes of both models. After I/R, eNOS immunoreactivity was increased in the testicular tissues. Ibuprofen treatment decreased eNOS immunoreactivity in the germ cells of the tubules in the contralateral testes, but intense eNOS immunoreactivity was shown in the ipsilateral testes of the LOM. Electron microscopy of the testes of rats demonstrated that ibuprofen pretreatment was particularly effective in preventing the mitochondrial degeneration in both Sertoli and spermatid cells in the LOM. Because of its anti-inflammatory and antioxidant effects, ibuprofen pretreatment may have protective effects in the experimental testicular torsion/detorsion model in rats.

Reactive oxygen species as an independent marker of male factor infertility

OBJECTIVE

To determine the abnormal patterns of reactive oxygen species (ROS) production in male factor infertility (MFI) patients and to define the ROS reference values in such patients.

DESIGN

A retrospective study.

SETTING

Male infertility clinic at a tertiary healthcare center.

PATIENT(S)

We examined 132 MFI patients (all normal sperm parameters, n = 24, and all abnormal sperm parameters, n = 38) and 34 healthy donors.

INTERVENTION(S)

Routine semen analysis, measurement of ROS.

MAIN OUTCOME MEASURE(S)

Sperm parameters, ROS levels (10(4) cpm/20 x 10(6) sperm).

RESULT(S)

Normal, healthy donors had significantly higher (P<.0001) sperm concentration, motility, and morphology compared with all MFI patients. Univariate analysis indicated a significant association between MFI and log (ROS + 1) (odds ratio [OR] = 3.84), besides sperm parameters and age. A multivariate model using logistic regression analysis also indicated an independent association of log ROS with MFI (OR = 4.25). The ROS cutoff values of 1.2-1.4 had a sensitivity of 0.70-0.78 with a corresponding specificity of 0.82. However, at a cutoff point of 1.2, the OR was 68.6, which increased with an increase in the cutoff.

CONCLUSION(S)

High ROS is an independent marker of MFI, irrespective of whether these patients have normal or abnormal semen parameters. We suggest the inclusion of ROS measurement as part of idiopathic infertility evaluation. Treatment with antioxidants may be beneficial in such patients.

Oleoylethanolamide protects human sperm cells from oxidation stress: studies on cases of idiopathic infertility

N-acylethanolamides are naturally occurring hydrophobic molecules usually present in a very small amount in many mammalian tissues and cells. The presence of N-acylethanolamides has also been demonstrated in human reproductive tracts and fluids, although their biological effects and molecular mechanisms of action are not yet completely elucidated. It is known that some N-acylethanolamides, such as oleoylethanolamide, have antioxidative properties. The aim of this study was to test whether oleoylethanolamide could protect sperm cells from reactive oxygen species-induced oxidative damage in cases of idiopathic infertility, because the excessive generation of these radicals was associated with this pathology. Our results show that 2.5 nM oleoylethanolamide in vitro supplementation significantly reduces DNA strand breaks both in fertile and infertile subjects. Moreover, oleoylethanolamide increases kinematic parameters, such as curvilinear velocity and amplitude of lateral head displacement and hyperactivation, both in the presence and in the absence of oxidative stress. Results of this study support the hypothesis of a possible protective action of oleoylethanolamide against reactive oxygen species, which could explain its beneficial effects on in vitro capacitated spermatozoa.