Formation of reactive oxygen species in spermatozoa of infertile patients.

OBJECTIVE: To determine the incidence of reactive oxygen species formation in semen of a population of patients consulting for infertility.
DESIGN: The incidence of reactive oxygen species formation in whole semen and in washed spermatozoa was studied. The values obtained were correlated with semen parameters. The effect of the type of sperm washing on reactive oxygen species formation was also investigated.
SETTING: Semen samples from patients consulting for infertility and control subjects were obtained by masturbation after 3 days of sexual abstinence. Reactive oxygen species formation was measured in whole semen, sperm suspension washed by Percoll gradients, or repeated centrifugations. Sperm motility parameters were measured by computer-aided sperm analysis. PATIENTS, PARTICIPANTS: Fertile control men and an unselected population of patients consulting for infertility.
INTERVENTIONS: None. MAIN OUTCOME MEASURE: Reactive oxygen species formation by fresh semen specimen or washed spermatozoa was measured in a computer-driven LKB 1251 Luminometer (LKB-Wallac, Turku, Finland).
RESULTS: Reactive oxygen species formation was detected in 40% of the semen with spermatozoa from infertile patients, whereas none was found in 6 azoospermic men and 10 control men. The level of reactive oxygen species formation was inversely correlated to the semen volume, the percentage of motile spermatozoa, and sperm linearity both in semen and in Percoll-washed spermatozoa. Washing by repeated centrifugation-resuspension increased 20- to 50-fold sperm reactive oxygen species formation. This enhancement was caused by the centrifugation itself and by the removal of seminal plasma. Both morphologically normal and abnormal spermatozoa produced reactive oxygen species.
CONCLUSION: The data suggest that reactive oxygen species formation by spermatozoa may be a significant cause for male infertility.