Effect of varicocele on sperm function and semen oxidative stress.

To assess the effect of varicocele on sperm DNA integrity, mitochondrial activity, lipid peroxidation and acrosome integrity. In all, 30 patients with a clinically diagnosed varicocele of grade II or III and 32 men without a varicocele were evaluated for sperm DNA fragmentation (comet assay), mitochondrial activity (3,3'-diaminobenzidine assay), lipid peroxidation (malondialdehyde) and acrosome integrity (fluorescent probe labelled peanut agglutinin). The varicocele group showed fewer spermatozoa with intact DNA (grade II, P= 0.040), more cells with inactive mitochondria (class III, P= 0.001), fewer cells with active mitochondria (class I, P= 0.005) and fewer spermatozoa with intact acrosomes (P < 0.001). Finally, no significant differences were observed in lipid peroxidation levels. Men with varicocele showed an increase in sperm DNA fragmentation and a reduction in mitochondrial activity and acrosome integrity. However, lipid peroxidation levels remained unchanged.