Glutathione content in sperm cells of infertile men

R V Fafula,O K Onufrovych,D Z Vorobets,O V Melnyk,I A Nakonechnyi,Z D Vorobets,U P Iefremova

doi:10.15421/021725

Abstract

Hyperproduction of reactive oxygen species can damage sperm cells and is considered to be one of the mechanisms of male infertility. Cell protection from the damaging effects of free radicals and lipid peroxidation products is generally determined by the degree of antioxidant protection. Glutathione is non-enzymatic antioxidant which plays an important protective role against oxidative damages and lipid peroxidation. The aim of the present work is to determine the content of reduced and oxidized glutathione in sperm cells of infertile men. Semen samples from 20 fertile men (normozoospermics) and 72 infertile patients (12 oligozoospermics, 17 asthenozoospermics, 10 oligoasthenozoospermics and 33 leucocytospermic) were used. The total, oxidized (GSSG) and reduced (GSH) glutathione levels were measured spectrophotometrically. The levels of total glutathione were significantly lower in the spermatozoa of patients with oligozoo-, asthenozoo- and oligoasthenozoospermia than in the control. Infertile groups showed signiﬁcantly decreased values of reduced glutathione in sperm cells vs. fertile men, indicating an alteration of oxidative status. The oxidized glutathione levels in sperm cells of infertile men did not differ from those of normozoospermic men with proven fertility. The GSH/GSSG ratio was signiﬁcantly decreased in the oligo-, astheno- and oligoasthenozoospermic groups compared to the normozoospermic group. In patients with leucocytospermia the GSH/GSSG ratio was lower but these changes were not significant. In addition, glutathione peroxidase activity in sperm cells was decreased in patients with oligozoo-, astenozoo-, oligoastenozoospermia and with leucocytospermia. The most significant changes in glutathione peroxidase activity were observed in infertile men with leucocytospermia. Decreased GSH/GSSG ratio indicates a decline in redox-potential of the glutathione system in sperm cells of men with decreased fertilizing potential. Redistribution between oxidized and reduced forms of glutathione can be caused by depletion of intracellular stores of glutathione and intensification of lipid peroxidation processes. This leads to increased production of reactive oxygen species, further depletion of antioxidant pools and disturbances of structure and function of spermatozoa. Our results indicate that the evaluation of reduced glutathione level and GSH/GSSG ratio in sperm cells of infertile men can be helpful in fertility assessment.

Highlights

It is well known that the processes of lipid peroxidation are universal mechanisms of cell damage
Cell protection from the damaging effects of free radicals and lipid peroxidation products is generally determined by the degree of antioxidant protection
Reduced glutathione exists in cells in equilibrium with oxidized glutathione (GSSH) and the GSH/GSSH ratio characterizes the redox state of the system in different physiological states (Kurilova et al, 2008)

Summary

Introduction

It is well known that the processes of lipid peroxidation are universal mechanisms of cell damage. Cell protection from the damaging effects of free radicals and lipid peroxidation products is generally determined by the degree of antioxidant protection. Under physiological norm a balance between the rate (intensity) of free radical processes and the activity of antioxidant systems is maintained. Reduced glutathione (GSH) and associated enzymes that form the glutathione antioxidant system are of particular importance in maintaining cell viability in antiradical and antiperoxide protection. The GSH content in cell depends on the balance of opposing processes such as de novo synthesis by gamma-glutamylcysteine synthetase, regeneration of GSSG by glutathionreductase and usage in neutralizing of H2O2 and secondary lipid peroxidation products (Iskra, 2011)

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