Functional role of sperm surface glutathione S-transferases and extracellular glutathione in the haploid spermatozoa under oxidative stress

On the sperm surface, glutathione S-transferases (GSTs) exist as oocyte binding proteins but their detoxitication function in this unique cell type is not known. Using H2O2- and 4-hydroxynonenal-induced sperm dysfunction models, this study demonstrates that the sperm surface GSTs are able to use extracellular reduced glutathione to inhibit the loss of functional competence of goat spermatozoa; however, in the presence of GST inhibitors, they are unable to do so. In the context of susceptibility of spermatozoa to oxidative stress, this finding that strategically located sperm surface GSTs are important for maintaining the functional competence of sperm is relevant to studies on male infertility. (C) 2003 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.