Glutathione peroxidase (GPX) activity in seminal plasma of healthy and infertile males

Abstract

Human spermatozoa are more dependent on glutathione peroxidase/glutathione reductase (GPX/GR) system, via reduced glutathione (GSH), to inactivate reactive oxygen metabolites (ROMs) such as hydrogen peroxide and organic hydroperoxides. To demonstrate whether there is a substantial difference in GPX activity between normal and pathological seminal plasma, we decided to evaluate the activity of this enzyme in healthy subjects and infertile males with normal hormonal patterns. Our results demonstrate that in healthy subjects the seminal plasma contains a GPX activity that is about 10 times greater than the GPX activity detected in the seminal plasma of infertile males. By using specific antibodies against plasmatic GPX (GPX3), we also demonstrate that enzymatic activity, detected in the seminal plasma of both healthy and infertile males is GPX3. Therefore, the evaluation of GPX activity in human seminal plasma could be a new useful marker of gonadal function in men.

Effects of reduced seminal enzymatic antioxidants on sperm DNA fragmentation and semen quality of Tunisian infertile men

“…This significant raise of seminal LPO in abnormal groups can be explained by the significant decrease of the enzymatic antioxidant activities (SOD, GPX and CAT) in infertile groups. These observations corroborated with the findings of [6,7,18,24] and highlighted the fundamental scavenging activity of these antioxidant enzymes against the oxidation of membrane lipids and the loss of sperm membrane integrity [28,34]. Moreover, we have clearly indicated that lowered antioxidant profile and elevated seminal MDA concentrations were closely associated with increased sperm DFI.…”

Glutathione peroxidase activity in seminal plasma and its relationship to classical sperm parameters and in vitro fertilization-intracytoplasmic sperm injection outcome

“…Although a number of studies have investigated the relationship between human seminal plasma GPX and semen parameters, results have not been consistent. Lower GPX levels have been reported among infertile men (27,28), as well as in patients with asthenozoospermia (29), while in other studies no relationship between these parameters was detected (30)(31)(32), and, surprisingly, in another study, higher levels of GPX were reported in males with oligozoospermia or asthenozoospermia (33). These discrepancies may be explained by sample sizes.…”

Supraphysiological Free Radical Levels and their Pathogenesis in Male Infertility

“…This mouse exhibits an age dependent increase in oxidative damage to sperm DNA which is, in turn, associated with high rates of miscarriage in mated females as well as birth defects in the offspring. Male factor infertility has been linked with a reduction in seminal plasma [163] and spermatozoa [164] GPX activity, further supporting an important role for this enzyme in male fertility. In addition, men exhibiting leukospermia-associated oxidative stress have been reported to have significantly reduced GPX activity within their spermatozoa [165].…”