ABSTRACT
The objective of this study was to determine the presence of reactive oxygen species (ROS), especially superoxide anion (O2-), in fresh and frozen-thawed canine semen, its effect on other seminal parameters and whether the freezing-thawing process influences the O2- production rate. A total of 56 mature male domestic dogs were used in this study. Their semen was examined before and after freezing-thawing process. Sperm motility, hypo-osmotic swelling, sperm morphology and O2- extracellular production were measured. The dogs were divided in two groups, with the criterion of the absence or presence of O2- in fresh semen (groups A and B, respectively). Values of group A were compared with the respective values of group B. A significant decrease in motility and percentage of swollen spermatozoa and an increase in morphological abnormalities and O2- production in group B were found in comparison with group A after freezing-thawing process (p < 0.05). It seems that the freezing-thawing process leads to an increase of the O2- production. However, it remains to be documented if the increased concentrations of O2- in canine semen are responsible for the alterations in the seminal parameters observed in this study.
