Oxidative stress and male infertility.

We have studied the activity of substances (superoxide dismutase [SOD], catalase [Cat], malonaldehyde, xanthine oxidase [XO], nitric oxide [NOx]) participating in oxidative stress. Seminal plasma samples of 147 ejaculates obtained from normal and from infertile males were examined. Activities of SOD, Cat, and XO were measured chemiluminometrically while malonaldehydes and NOx were measured by spectrophotometer in seminal plasma samples. Ejaculates were previously characterized according to World Health Organization andrological criteria (sperm number, motility, and morphology). Procedures were performed in a university laboratory. Statistically significant changes (in comparison to normozoospermic samples) were noted in activities of SOD, XO, and malonaldehyde levels. The SOD activity exceeded values obtained for normozoospermic samples only in oligozoospermia. Otherwise low SOD levels in analyzed infertile subgroups inversely related to elevated malonaldehydes. Because diminished activity of SOD in seminal plasma was associated with increased levels of malonaldehydes and XO, we could postulate some significance of these monitored substances in evaluation of the cause of male infertility.