SummaryBackgroundInfertility is an important worldwide problem which affects 10–15% of couples globally. Altered NO production has also been implicated in the pathogenesis of the male infertility. The present study was designed to evaluate the changes in the activity of NO-synthase (NOS) and arginase in spermatozoa of patients with infertility.MethodsThe total NOS, Ca2+-dependent constitutive (cNOS) and Ca2+-independent inducible (iNOS) activity and arginase activity were assessed in sperm cells of patients with different forms of pathospermia.ResultsWe found a significant increase in iNOS activity, but significantly decreased cNOS and arginase activity in sperm cells of infertile men vs fertile, normozoospermic men (p<0.001). The arginase/NOS ratio significantly decreased compared to control group. The iNOS/cNOS ratio was drastically increased in patients with decreased fertility potential indicating predominance of iNOS. Men with leuko cytospermia were distinguished to have the most express iNOS activity.ConclusionsThese observations provide evidence for a disturbed balance between the L-arginine metabolic pathways in sperm cells of infertile men. This imbalance includes the considerable activation of the inducible isoform of NO-synthase accompanied by significant inhibition of its constitutive isoform which indicates disturbances in NO production. In patients with decreased fertility potential the arginase/NOS was shifted towards predominance of iNOS-derived NO production.

The present study was carried out with the aim to evaluate the relation of the content of proinflammatory and antiinflammatory cytokines with the sperm quality indicators. The study involved 45 patients with a pathological spermogram and 15 practically healthy men. A positive correlation (r = 0.45) between the content of IL-6 and the sperm concentration in the ejaculate and a negative correlation (r =-0.42) of this cytokine with the number of live sperm were revealed. The concentration of IL-8 was positively correlated with sperm density (r = 0.52) and it was negatively correlated with the number of live sperm (r =-0.55). A positive correlation between the content of IL-10 and the sperm concentration as well as the number of active forms was observed (r = 0.45 and 0.5, respectively), and a negative correlation (r =-0.7) was observed between the ejaculate volume and the concentration of IL-10. In the obtained ejaculates, a close positive correlation between the content of IL-8 and IL-6 (r = 0.74) and between the concentration of IL-10 and IL-6 (r = 0.72) was observed. Based on the completed study, a conclusion was made that the increased level of IL-6 and IL-8 may result in the reduction of the sperm quality, and, possibly, infertility, and that IL-10 plays an important role in improving sperm parameters.

Nowadays the role of NO in the development of male infertility is actively studied. Arginase (EC 3.5.3.1) is a manganese metalloenzyme which converts L-arginine to L-ornithine and urea and reciprocally regulates NO production. Although arginase activity has usually been detected in the reproductive tract, including spermatozoa, no data relating to the kinetic properties of the enzyme in ejaculated spermatozoa has been reported. This study was designed to study the kinetic parameters of arginase of spermatozoa of infertile men. Spermatozoa arginase activity was measured by determining levels of urea production. Kinetic analysis of the enzyme reaction was performed in a standard incubation system with modified physical and chemical characteristics or the respective components (the substrate concentration, Mn2+ concentration, incubation time and protein content). Pathobiochemical and kinetic properties of sperm arginase obtained from human normozoo- and pathospermic samples were compared. The maximum rate of L-arginine hydrolysis (detrermined by L-arginine) for arginase of spermatozoa obtained from men with preserved fertility was 2.0, 1.8 and 1.9 times greater than this value for oligo-, astheno- and oligoasthenozoospermic samples respectively. However, affinity constants for L-arginine was not significantly different between fertile and infertile men. The maximum rate of L-arginine hydrolysis (deretmined by Mn2+) for arginase of spermatozoa obtained from men with preserved fertility was 1.6, 1.7 and 1.7 times greater than this value for oligo-, astheno- and oligoasthenozoospermic samples respectively. However, affinity constants for Mn2+ were not significantly different between fertile and infertile men. In the whole range of time, the urea production by arginase in sperm cells obtained from oligozoospermic samples is much lower compared to value in healthy donors. The results of kinetic analysis indicate that urea production by arginase is much more intense in the control group than in patients with various forms of pathospermia. The initial (instantaneous) reaction rate of arginase reaction was lower for oligozoospermic samples compared to normozoospermic samples. It has been found that inhibition of arginase activity in sperm cells of infertile men occurs by non-competitive type and was related to marked decrease in maximum reaction rate while affinity of arginase to L-arginine and Mn2+ was unaffected.

Context: Obesity and infertility are the major global public health problems. The evidences of adverse impact of adiposity on male fertility are contradictory. Aim: The objective of the study was to determine the effect of overweight and obesity on ejaculate quality, in particular, sperm parameters and biochemical markers. Subject and Design: The study involved 152 men who were distributed into three groups according to the body mass index (BMI, kg/m 2 ): control group with normal values (18.5–24.9), preobese (25.0–29.9), and obese (≥30.0). Materials and Methods: Semen analysis included parameters: volume, sperm concentration and total count, morphology, progressive (PR) and total motility. Levels of fructose, citric acid, and zinc were measured in seminal plasma. Statistic: The results of the studies were analyzed using StatPlus: mac (AnalystSoft Inc., version 6). The Mann–Whitney U-test was used to compare groups. Pearson's correlation coefficient was calculated. P < 0.05 was considered statistically significant. Results: No significant differences of the semen parameters were observed between preobese and control group, except for increasing the number of abnormal spermatozoa. The obese group revealed lower concentration and total number of sperm, PR motility. BMI was negatively correlated with most semen parameters. The overweight group showed a decreasing of fructose levels and increasing of citric acid and zinc concentration, while no significant changes were observed in the obese group, except for a decreasing in fructose. Conclusions: The present study confirms that with the growth of BMI, the sperm quality deteriorates. Based on these results, we can assume that obesity may be an injurious factor of male infertility.

Na+,K+-ATPase plays an essential role in sperm motility, hyperactivation, chemotaxis, acrosome reaction etc. Na+,K+-ATPase is sensitive to ROS insult. Apart from production of highly reactive molecules, H2O2 can exert a number of direct effects on cells, their metabolism and enzymes. In the present study, exposure to exogenous H2O2 was used to characterize the effects of H2O2 on Na+,K+-ATPase activity in spermatozoa of infertile men with different forms of pathospermia. It was shown that Na+,K+-ATPase activities in spermatozoa of infertile men with different forms of pathospermia were inhibited by exposure to H2O2 (50−500 μM). H2O2, one of the most toxic oxygen species, has the ability to depress Na+,K+-ATPase activity in a dose-dependent manner. Severe inhibition of the hydrolytic activity was observed when higher H2O2 were used. The time course of incubation with 100 μM H2O2 showed a sharp decrease in the enzyme activity during the first 5 min of incubation for both normozoospermic and pathozoospermic men. The enzymatic activity of Na+,K+-ATPase in the sperm was completely destroyed at 20 min for asthenozoospermic men and 30 min for normozoospermic men. We show that an administation of H2O2 inhibited Na+,K+-ATPase activity in normozoospermic samples with IC50 of 106.6 ± 7.9 μM. IC50 for patients with asthenozoospermia was two times less than for healthy men with preserved fertility. For other studied groups, the differences in IC50 were not significant. These observations suggest that Na+,K+-ATPase in pathozoospermic samples is more vulnerable to H2O2-induced damage than in normozoospermic men. The Hill coefficient was significantly increased only for patients with asthenozoospermia, indicating increased positively cooperative binding. The decreases in Na+,K+-ATPase hydrolase activity in H2O2-treated sperm cells in men with normozoospermia were largely attenuated by exogenous GSH at 5 mM. This suggests that GSH partially protects the Na+,K+-ATPase from inhibition under experimental oxidative stress. However, treatment of oligo-, astheno- and oligoasthenozoospermic samples with 100 μM H2O2 and 5 mM GSH did not result in protection of Na+,K+-ATPase against induced oxidation, suggesting that the impaired Na+,K+-ATPase in pathozoospermic samples appears to be an irreversible event. In contrast, presence of GSH only after H2O2 treatment does not reverse Na+,K+-ATPase inhibition. This study has provided a deeper insight into the role Na+,K+-ATPase plays in sperm cells,it also could offer clues to the clinical application of antioxidant therapy in male infertility therapy.