Evaluation of the role of reactive oxygen species in male infertility.

Reactive oxygen species (ROS) production from spermatozoa has been measured by chemiluminescence in the two fractions of a Percoll gradient column (47 and 90%). Chemiluminescent signals were recorded in each fraction after the addition of luminol and horse-radish peroxidase (basal state), and after stimulation with formyl-methionyl-leucyl-phenylalanine and phorbol ester (PMA). Oligozoospermic samples show a higher rate of ROS production than the normozoospermic samples in both fractions of Percoll. Also, ROS were generated at a higher rate by asthenozoospermic samples in the 90% Percoll fraction than by normal samples after stimulation with PMA. Our data confirm that fact that white blood cells play a major role in the production of ROS, even after purification on a Percoll gradient. Immunological cases were also found to be associated with an increased production of ROS, which may be caused by the same underlying pathological condition responsible for the production of the antibodies. Repeated centrifugation of the samples triggers a burst of ROS in excess of that produced after Percoll preparation. In addition, superoxide dismutase activity was found to be significantly increased in cases with an elevated production of ROS. It is concluded that measuring the ROS generation by semen may yield useful information on the functional capacity of spermatozoa, which may be used to improve the success of male infertility management.