Glutathione s-transferase as a marker of oxidative stress in human ejaculated spermatozoa from patients with pathospermia

Regulatory Mechanisms in Biosystems

O. K. Onufrovych¹  R. V. Fafula¹  D. Z. Vorobets¹  A. S. Besedina¹  M. Z. Vorobets¹ 

[1] Danylo Halytsky Lviv National Medical University

关键词: glutathione S-transferase activity;    lipid peroxidation;    antioxidant protection;    sperm cells;    pathospermia;    male infertility;   

DOI  :  10.15421/021842

学科分类：自然科学（综合）

来源: Oles Honchar Dnipro National University

【 摘 要 】

It is believed that the most common causes of male infertility are impairment of spermatogenesis and sperm functions. Glutathione S-transferases (EC 2.5.1.18) play an important role in sperm physiology, specifically in antioxidant protection against oxidative damage. The catalase decomposition of lipid hydro-peroxides forms as a result of oxidative stress. We used a model of superoxide anion-generating system Fe3+/ascorbate or H2O2-induced stress to study the activity of glutathione s transferase in human ejaculated spermatozoa from patients with pathospermia and products of lipid peroxidation (TBARS) as a marker of oxidative stress. In the present study, dose dependent increase in the level of lipid peroxidation was observed for treatment with Fe3+/ascorbate or H2O2. The TBARS level was higher for sperm cells incubated with superoxide anion-generating system Fe3+/ascorbate than for H2O2. GSTs activity increased in spermatozoa treated with increasing concentration of superoxide anion-generating system Fe3+/ascorbate and H2O. We found that both Fe3+/ascorbate and H2O2 displayed similar inhibitory effects on sperm GSTs activity, however H2O2 at low concentrations activated enzyme activity only in normozoospermic samples, which can be explained as a defence response to oxidative stress. The time course of incubation with 100 μM H2O2 showed a sharp decrease in the enzyme activity during the first 5 min of incubation for both normozoospermic and pathozoospermic men. Preincubation of spermatozoa with GSH completely prevented the ROS-induced inhibition on GSTs only in normozoospermic samples. On the other hand, in pathospermic samples protectory effect of GSH was observed only against non-radical (H2O) radical, but not against radical (superoxide anion-generating system Fe3+/ascorbate) species. The results of our study showed higher oxygen-free radical production, evidenced by increased TBARS level in spermatozoa obtained from infertile men than normozoospermic men. The inhibitory effect of the radical (superoxide anion-generating system Fe3+/ascorbate) species on sperm GSTs activity and products of lipid peroxidation in sperm cells of fertile and infertile men were more expressed compared to non-radical (H2O) species. Our results indicate that estimation of sperm GSTs enzyme assays can be used as a bioindicator for impaired male fertility. The obtained results argue for a biological role of sperm GSTs in susceptibility of spermatozoa to oxidative damage and maintaining sperm antioxidant status.

【 授权许可】

CC BY