STIMULATION OF OXIDANT GENERATION BY HUMAN SPERM SUSPENSIONS USING PHORBOL ESTERS AND FORMYL PEPTIDES - RELATIONSHIPS WITH MOTILITY AND FERTILIZATION IN-VITRO

Objectives: To investigate the influence of reactive oxygen species ge nerated by human spermatozoa and contaminating leukocytes on sperm mov ement and fertilization in vitro. Design: A chemiluminescence techniqu e, using luminol and peroxidase, was used to monitor the generation of reactive oxygen species by human sperm suspensions and the results we re correlated with sperm movement and the fertilization of human ova i n vitro. Setting: Diagnostic Andrology Laboratory and IVF Clinic. Pati ents: Infertile couples undergoing IVF therapy. Results: An N-formyl-m ethionyl-leucyl-phenylalanine (FMLP) provocation test was used to demo nstrate that the presence of leukocytes in 28.5% of the sperm preparat ions was associated with elevated levels of spontaneous reactive oxyge n species production, impaired movement, and a reduced capacity for fe rtilization in vitro. In the absence of leukocytes, exposure to phorbo l ester stimulated a burst of reactive oxygen species generation by hu man spermatozoa, the magnitude of which was correlated highly with a l oss of sperm motility but not with fertilization rates observed in the concurrent IVF cycle. Conclusion: Leukocyte contamination of human sp erm preparations can be detected readily by FMLP-induced, luminol-depe ndent chemiluminescence and the results have an important bearing on t he fertilizing capacity of the spermatozoa in vitro.