Human sperm superoxide anion generation and correlation with semen quality in patients with male infertility.

OBJECTIVE To measure levels of reactive oxygen species (ROS) including H(2)O(2) and O(2)(.-) generation in infertile men and determine whether sperm quality is correlated with levels of ROS triggered by the exogenous reduced form of beta nicotinamide adenine dinucleotide phosphate (NADPH). DESIGN Prospective study. SETTING Male infertility clinic at a tertiary healthcare center. PATIENT(S) Eleven infertile men and six healthy donors. INTERVENTION(S) Chemiluminescence assay using luminol and lucigenin as probes before and after incubating sperm samples with 5 mM and 10 mM of NADPH. MAIN OUTCOME MEASURE(S) The ROS generation (10(6) counted photons per minute/10(6) sperm). RESULT(S) Baseline levels of O(2)(.-) generation were significantly higher in the infertile patients than in the healthy donors (r = 0.73, 95% confidence interval [median (25th, 75th percentiles): 0.73 (0.5, 5.5) vs. 0.2 (0.0, 0.5)] when lucigenin was used as the probe. Compared with basal levels, O(2)(.-) generation was significantly higher after coincubation with NADPH (5 mM and 10 mM) in the entire combined study population, and patients only but not donors. The O(2)(.-) generation was negatively correlated with sperm concentration (r = -0.75, 95% CI 0.38-1), motility (r = -0.69, 95% CI 0.28-1), and percentage of normal morphology (r = -0.78, 95% CI 0.36-1). CONCLUSION(S) Spermatozoa from infertile men produce higher levels of O(2)(.-) in the presence of exogenous NADPH compared to healthy donors. The ability of spermatozoa to generate O(2)(.-) increases as the semen quality declines.