Vasectomy reversal associated with increased reactive oxygen species production by seminal fluid leukocytes and sperm

Reactive oxygen species, which are primarily produced by leukocytes, are generally detrimental to sperm. High reactive oxygen species levels are found in men with abnormal sperm function. Since men often have poor sperm characteristics and infertility after vasectomy reversal, we compared reactive oxygen species in seminal cells of men after vasovasostomy to those of fertile men to determine if reactive oxygen species were elevated in the former group.

We studied semen samples of men with proved fertility (39) and those with previously proved fertility who had undergone vasectomy reversal (45). The presence of leukocytes was determined by Bryan-Leishman staining. Reactive oxygen species endogenous activity was monitored by luminol dependent chemiluminescence in washed cells, including all cells in the semen, and Percoll density gradient purified sperm.

After vasovasostomy men had significantly lower sperm concentration, motility and computerized motility measurements than fertile men. Mean reactive oxygen species in washed seminal cells after vasovasostomy was 684 relative light units per second compared to 49 for fertile controls (p < 0.0001). Density gradient purified sperm had 53 and 0.64 relative light units per second, respectively (p < 0.0001). When men with leukocytospermia were excluded from analysis, differences between the groups remained, although 9 times more reactive oxygen species were detected in men after vasectomy reversal with than those without leukocytes in semen.

Higher levels of reactive oxygen species are found in washed seminal cells and purified sperm after vasectomy reversal than in those of fertile men. Although leukocytes are probably a significant source of reactive oxygen species in these groups, they may not account for all of the increased reactive oxygen species after vasovasostomy. Low motility after vasectomy reversal may be related to the detrimental effects of reactive oxygen species produced by leukocytes or sperm, even in men without clinical leukocytospermia.