Antioxidant activity in the semen of fertile and infertile men

Objectives. To evaluate catalase- and superoxide dismutase (SOD)-like activ ities in the seminal plasma of fertile and infertile men. Methods. Semen samples were obtained from consecutive men presenting for va sectomy (n = 12) and infertility evaluation (n = 105) at our institution. C atalase-like activity was measured by the decrease in hydrogen peroxide aft er incubation with seminal plasma. SOD-like activity was measured as the in hibition of nitroblue tetrazolium reduction due to superoxide anion generat ion by xanthine plus xanthine oxidase. Results. Mean seminal catalase-like activity (+/-SEM) in fertile men was no t significantly different from that of infertile men (369 +/- 49 versus 326 +/- 17 U/mL, respectively). Mean SOD-like activity in the semen of inferti le men was significantly greater than in the semen of fertile controls (46. 7 +/- 1.5 versus 37.0 +/- 2.8 U/mL, respectively, P <0.05). Conclusions. Our data show that infertile men do not have deficient seminal plasma SOD- and/or catalase-like activity (two key antioxidants). These fi ndings suggest that the high semen ROS levels in some infertile men are lik ely due to excessive generation of ROS rather than deficient ROS scavenging activity in semen. UROLOGY 55: 922-926, 2000. (C) 2000, Elsevier Science I nc.