Expression of extracellular glutathione peroxidase type 5 (GPX5) in the rat male reproductive tract

The mammalian epididymis is the site of expression and secretion of an abundant, tissue-specific, androgen-regulated, selenium-independent, glutathione peroxidase isoenzyme (GPX5), which has been proposed to play a role in protecting the membranes of spermatozoa from the damaging effects of lipid peroxidation and/or preventing premature acrosome reaction. Using a combination of reverse transcription-polymerase chain reaction, Northern blot analysis and Western blotting, we now describe in detail the developmental expression of GPX5 transcripts and protein in the rat epididymis and characterize the association of rat GPX5 with the sperm plasma membrane.