In vitro effects of peroxynitrite on human spermatozoa

In the present study, the in vitro effects of peroxynitrite on sperm motili ty, lipid peroxidation and sulfhydryl content were examined. Sperm percenta ge motility and movement characteristics were assessed by a computer-assist ed system. Lipid peroxidation was measured by determining malondialdehyde l evels using the thiobarbituric acid (TBA) method. Sperm sulfhydryl content was measured by a spectrophotometric method based on reduction of 5,5'-dith iobis-(2-nitrobenzoic acid) by sulfhydryl groups. Percentage motility, move ment characteristics and sulfhydryl content decreased significantly in pero xynitrite-treated samples compared to decomposed peroxynitrite-treated samp les. Lipid peroxidation in peroxynitrite-treated samples was significantly higher than in decomposed peroxynitrite-treated samples. These results indi cate that peroxynitrite anion may cause sperm dysfunction through lipid per oxidation stimulation and total SH depletion.