IATROGENIC DNA-DAMAGE INDUCED IN HUMAN SPERMATOZOA DURING SPERM PREPARATION - PROTECTIVE SIGNIFICANCE OF SEMINAL PLASMA

Before the advent of intracytoplasmic sperm injection (ICSI) semen pre paration techniques focused on the need to sustain the fertilizing pot ential of the spermatozoa particularly by reducing oxidative stress. H owever, for severely oligozoospermic patients treated by ICSI, sperm p reparation protocols are used which aim to maximize sperm recovery rat her than sperm function. In this study we have examined the impact of different sperm preparation techniques on oxidative stress, sperm moti on and DNA integrity. Reactive oxygen species (ROS) generation was mon itored using luminol-dependent chemiluminescence, seminal antioxidant activity was assessed using a total reactive antioxidant potential (TR AP) assay while sperm motility and DNA damage were evaluated using com puter assisted semen analysis and in-situ nick translation respectivel y. The results demonstrate a significant increase in the levels of ROS generated by samples prepared by swim-up from a washed pellet compare d with spermatozoa isolated directly from seminal plasma. This oxidati ve stress was associated with a highly significant increase in the lev el of DNA damage sustained by the spermatozoa while the quality of spe rm motility remained largely unchanged. These results suggest that if repeated centifugation protocols are to be used to prepare spermatozoa , strategies should be developed for minimizing collateral DNA damage.