INTRODUCTION: The origin of reactive oxygen species (ROS) in semen remains controversial. Phagocytic leukocytes present in semen are known to produce high levels of ROS that can overwhelm the ROS-scavenging capacity of seminal plasma and eventually lead to oxidative stress. Although immature spermatozoa have also been shown to produce high levels of ROS, the role of leukocytes in stimulating ROS ... Read more