Relationship between ROS production, apoptosis and DNA denaturation in spermatozoa from patients examined for infertility

BACKGROUND: The aim of this study was to examine the role of apoptosis and reactive oxygen species (ROS) in inducing DNA damage in ejaculated spermatozoa. METHODS: We examined ejaculated spermatozoa from 31 patients examined for infertility and 19 healthy donors for apoptosis, production of ROS and DNA damage using annexin V binding, chemiluminescence assay and sperm chromatin structure assay. RESULTS: The percentage of spermatozoa that underwent apoptosis in the whole ejaculate and mature fraction was higher in the patients than in the donors (P<0.001 and P=0.009, respectively). Levels of ROS in the whole ejaculate and immature fraction were higher in the patients than in the donors (P=0.002 and P=0.009). Apoptosis was significantly correlated with ROS within patients in the whole ejaculate r (95% confidence interval)=0.53 (0.19-0.86)] and in the mature 0.71 (0.39-1.00)] and immature spermatozoa 0.75 (0.45-1.00)]. Only apoptosis and the DNA fragmentation index (DFI) were significantly correlated within patients in the whole ejaculate 0.57 (0.18-0.97)]. CONCLUSIONS: DNA damage may be induced by oxidative assault. Apoptosis may not contribute significantly to the DNA damage.