Reactive oxygen species released by activated neutrophils, but not by deficient spermatozoa, are sufficient to affect normal sperm motility.

OBJECTIVES

To determine whether reactive oxygen species (ROS) produced by abnormal or deficient spermatozoa and polymorphonuclear leukocytes (PMN, activated or not) can affect normal sperm motility. To determine what level of ROS is detrimental to spermatozoa.

SUBJECTS

Patients consulting the Infertility Clinic at the Royal Victoria Hospital and healthy volunteers.

METHODS

Normal spermatozoa (not producing ROS) were incubated with ROS-producing spermatozoa or PMN (activated or not), and motility was analyzed using a computer-aided sperm analysis system. The proportion of ROS produced by spermatozoa and released extracellularly was estimated by the decrease in the chemiluminescence observed in the presence of catalase and superoxide dismutase.

RESULTS

There was no consistent effect on motility when ROS-producing and non-ROS-producing spermatozoa were mixed. This lack of effect could be due to the relatively low level of ROS produced by spermatozoa as well as the fact that only a third of these ROS are released outside spermatozoa. To cause a low but significant decrease (15 +/- 4%) in sperm motility after a 5-hour incubation, the level of ROS imposed on spermatozoa must be equivalent to ROS released by 1 x 10(6) activated PMN/mL.

CONCLUSIONS

The production of ROS by deficient spermatozoa is low and of no consequence to the motility of normal spermatozoa present in the same sperm preparation. However, 1 x 10(6) activated PMN/mL, with a 1,000-fold higher ROS production, have detrimental effects on the motility of normal washed spermatozoa.