Glutathione and male fertility

ABSTRACT

Considerable efforts are now focused on the identification of ultrastructural and/or molecular defects in the seminal fluid from infertile men. The tripeptide glutathione is the most abundant non-thiol protein in mammalian cells. It is a part of the protein identified as the major constituent that embeds the helix of mitochondria in the midpiece of spermatozoa. The objective of this work is to clarify the role played by seminal plasma glutathione on male fertility. A randomly selected group of 25 nonazoospermic infertile patients were included in this study, who attended the Institute of Embryo Research and Infertility Treatment at Al-Kadhimiya City/ Baghdad, with a history of infertility of at least 1 year duration between March and June 2009. Controls consisted of samples obtained from healthy donors of proven fertility [n = 10]. The seminal plasma glutathione concentration and percentage of spermatozoa with low mitochondrial membrane potential [MMP] were studied in the ejaculate from infertile patients against control donors. Results were compared with the standard semen characteristics [concentration, motility and morphology]. Infertile patients had significantly lower amount of GSH in the seminal plasma [P = 0,00001], lower progressive motility [grades a and b] [P = 0,002] and poorer sperm morphology [P = 0.00001]; while they had higher percentage of spermatozoa with low MMP [P = 0,00001] as compared to controls. Most of infertile patients were non oligozoospermic therefore; no significant concentration difference was found compared to controls. Seminal glutathione concentration was significantly inversely correlated with low MMP [r = - 0.665, P = 0.001], yet it was positively related to progressive motility [r = 0.51, P = 0.02] and normal morphology [r = 0.611, P = 0.004]. Comparison between patients with asthenoteratozoospermia [low percentage of progressive motility and normal morphology] [n = 18] against other patients [n = 7] revealed significantly lower seminal GSH concentration [P = 0.02] and higher percentage of low MMP [P = 0.00001]. This further support the relation between GSH and mitochondrial status, motility and normal morphology of spermatozoa. Seminal plasma GSH levels may play an important role in male fertility through protection against oxidative damage and preserving the mitochondrial integrity and function of the spermatozoa as the main energy source