The Glutathione and Thiol Content of Mammalian Spermatozoa and Seminal Plasma

Abstract

The glutathione and thiol contents of spermatozoa and seminal plasma of several animal species have been examined. Washed, ejaculated or epididymal spermatozoa from man, dog, ram and goat were found to contain about 5 (1–13) nmoles of glutathione per 109 cells. Little or none was present in rabbit and boar spermatozoa. In contrast, the total thiol content of the sperm samples was 350 (95–700) nmoles/109 cells, but almost all of it was protein-bound. Dog and human seminal plasma similarly contained thiol groups which were almost entirely protein-bound. The concentration of glutathione in seminal plasma was less than 2 μM. The spermatozoa which contained glutathione also exhibited substantial glutathione reductase and glutathione peroxidase activities. These findings suggest the possibility that these enzymes and glutathione may be functional in the spermatozoa of some animals as a protective mechanism against oxidative damage by H2O2, as has been demonstrated in other cells.