The assessment of oxidative stress in infertile patients with varicocele.

To assess oxidative stress markers, antioxidant capacity and cytokines in seminal plasma from infertile patients with varicocele, and to investigate seminal oxidative status and sperm DNA damage after varicocelectomy. The records were retrospectively evaluated for 28 azoospermic, 30 oligospermic (15 with varicocele and 15 without) and 30 patients with normal semen characteristics (15 with varicocele and 15 without). The mean (sd) age of the men was 32.4 (5.6) years; all men with varicocele had a unilateral or bilateral microsurgical subinguinal varicocelectomy. The level of nitric oxide (NO), 8-hydroxy-2'-deoxyguanosine (8-OHdG), hexanoyl-lysine (HEL), superoxide dismutase (SOD) activity, interleukin (IL)-6, IL-8 and tumour necrosis factor-alpha in seminal plasma were measured. In addition, sperm DNA fragmentation was analysed before and 6 months after varicocelectomy. Azoospermic and oligospermic patients had a significantly higher HEL concentration and SOD activity in seminal plasma; those with varicocele had a significantly higher NO, HEL, and SOD activity in seminal plasma. There was a significant increase in sperm concentration and reduction in NO, HEL, 8-OHdG level and SOD activity after varicocelectomy. Oligospermic patients with varicocele had a significantly higher IL-6 level in seminal plasma, and there was a significant reduction after varicocelectomy. The percentage of apoptosis-positive sperm decreased significantly after varicocelectomy. This study indicates that the seminal plasma of patients with varicocele is under excessive oxidative stress, and partly even in patients with normospermia, and that varicocelectomy reduces oxidative stress in seminal plasma and ameliorates sperm DNA damage.