Detection of oxidative DNA damage in human sperm and its association with sperm function and male infertility

The expanding research interest in the last two decades on reactive oxygen species (ROS), oxidative stress, and male infertility has led to the develo pment of various techniques for evaluating oxidative DNA damage in human sp ermatozoa. Measurement of 8-hydroxydeoxyguanosine (8-OHdG) offers a specifi c and quantitative biomarker on the extent of oxidative DNA damage caused b y ROS in human sperm. The close correlations of 8-OHdG level with male fert ility, sperm function and routine seminal parameters indicate the potential diagnostic value of this technique in clinical applications. On the other hand, single cell gel electrophoresis (SCGE or comet assay) and terminal de oxynucleotidyl transferase (TdT) mediated dUTP nick end labeling (TUNEL) as say have also been demonstrated to be sensitive, and reliable methods for m easuring DNA strand breaks in human spermatozoa. As certain technical limit ations were inherent in each of these tests, it is believed that a combinat ion of these assays will offer more comprehensive information for a better understanding of oxidative DNA damage and its biological significance in sp erm function and male infertility. (C) 2000 Elsevier Science Inc.