Abstract

Objectives: Reactive oxygen species (ROS) such as the superoxide anion (.O2-), hydrogen peroxide (H2O2) and the hydroxyl radical (.OH) can be produced by spermatozoa or infiltrating leucocytes in human semen. ROS can lead to deleterious effects on some of the sperm parameters including morphology and motility. To counteract the effects of ROS, spermatozoa and seminal plasma possess systems to scavenge ROS and prevent internal cellular damage. The presence of superoxide dismutase (SOD) and of the glutathione peroxidase/reductase system in human semen is well established. Sperm membranes are particularly susceptible to ROS damage because of their high content of polyunsaturated fatty acıds. Pro-oxidant and antioxidant balance is vital for normal functioning of cells and some studies have shown that spermatozoa possess antioxidant systems to scavange ROS. Superoxide dismutase (SOD), glutathione peroxidase/reductase (GPx/GR) and catalase (CAT) enzymatic antioxidant systems were demonstrated by some researchers in semen. Superoxide dismutase acts as a major intracellular protective enzyme against oxygen toxicity by catalasing the ablation of superoxide anion (.O2-).

The aim of our study is to determine the concentrations of superoxide dismutase and total antioxidant capacity in the seminal plasma of fertil and infertil men and observe whether they have any relevance in infertility.

Material and Methods: 51 individuals who were admitted to Istanbul University, Cerrahpasa Faculty of Medicine, Department of Urology were included in the study. Semen samples were liquefied at room temperature for one hour and used for routine sperm analysis according to World Health Organization’s (WHO) standards. After liquefication semen samples were centrifuged to separate seminal plasma. All samples were classified in 3 groups; group 1 was composed of 20 men with normal semen parameters, and considered as fertile group, group 2 was composed of 21 men with at least 2 years of infertility attributed to male factor and with poor semen quality, group 3 was composed of 10 men with azoospermia. Seminal plasma Cu-Zn SOD activity was measured kinetically (Sun et al, 1988) and total antioxidant status (TAS) was determined by colorimetric kit from Randox Laboratories (Antrim,U.K.).

Results: The mean value of the SOD activities and TAS levels in seminal plasma of three groups were not different but a significant negative correlation was found between SOD activities and sperm motility in infertile group (p=0.048, r=-0.435) and there was no significant correlation observed between TAS levels and sperm parameters.

Conclusion: These data suggest a significant role for SOD in sperm motility. The SOD activity in the seminal plasma may protect sperm motility again a loss induced by lipid peroxidation and may has an essential role in maintaining sperm motility.