Native specific activity of glutathione peroxidase (GPx-1), phospholipid hydroperoxide glutathione peroxidase (PHGPx) and glutathione reductase (GR) does not differ between normo- and hypomotile human sperm samples

Glutathione-dependent selenoenzymes in human spermatozoa are responsible for a generalized protection against reactive oxygen species (ROS) as well as some other metabolic and structural regulation during spermiogenesis and sperm cell maturation. Glutathione peroxidase (GPx-1), phospholipid hydroperoxide glutathione peroxidase (GPx-4 or PHGPx) and glutathione reductase (GR) native specific activities have been studied in human Percoll-purified spermatozoa from healthy fertile subjects and asthenozoospermic patients. The mean values obtained for the three enzymes in normal specimens are 1.52 +/- 0.90 mU/10(6) sperm cells (PHGPx), 4.26 +/- 1.73 mU/10(6) sperm cells (GPx-1) and 1.95 mU/10(6) sperm cells (GR). No statistically significant differences for any of the three enzymes were encountered between these values and those of asthenozoospermic patients. These results are discussed and compared with recent literature data on both rescued and native PHGPx specific activity in human spermatozoa, as well as with data obtained for GPx in human seminal plasma.