Relationship among standard semen parameters, glutathione peroxidase/glutathione reductase activity, and mRNA expression and reduced glutathione content in ejaculated spermatozoa from fertile and infertile men

Abstract

OBJECTIVE: To determine the expression and enzymatic activity of glutathione peroxidase (GPX)-1, GPX-4, and glutathione reductase together with glutathione (GSH) concentrations in spermatozoa from fertile and infertile men. DESIGN: Prospective study. SETTING: University-affiliated private center. PATIENT(S): Fifty-four infertile men undergoing assisted reproduction techniques and 55 fertile sperm donors with pregnancies and newborns by artificial insemination. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Analysis of gene expression by fluorescent quantitative polymerase chain reaction and an analysis of enzymatic activity and GSH concentration by controlled biochemical reactions and spectrophotometry. RESULT(S): GPX-4 activity but not mRNA expression is directly related to sperm morphology (strict criteria) and is more compromised with a low percentage of normal sperm. These differences are also demonstrated when fertile and infertile men were compared. In addition, intracellular GSH concentrations are lower when sperm morphology is severely impaired, but no differences were found between fertile and infertile men. CONCLUSION(S): Intracellular sperm GSH system components GPX-4 and GSH are altered in infertile men, and these alterations seem to be linked to sperm morphology.