Oxidative stress alters membrane sulfhydryl status, lipid and phospholipid contents of crossbred cattle bull spermatozoa

Ferrous ascorbate (FeAA: FeSO4 + ascorbic acid) has been used in the past by different investigators to induce oxidative stress. The optimum dose of FeAA for inducing oxidative stress by affecting thiols [total thiols (TSH), glutathione reduced (GSH), glutathione oxidized (GSSG), redox ratio (GSH/GSSG)], total lipids and phospholipids has been ascertained in the local crossbred cattle bull spermatozoa. The fractions of spermatozoa suspended in 2.9% sodium citrate were subjected to three doses of FeAA (100 mu M:500 mu M, 150 mu M:750 mu M, 200 mu M: 1000 mu M; FeSO4 :ascorbic acid), and were assessed for various parameters. On increasing the concentration of FeAA, a gradual decrease in TSH, GSH, GSH/GSSG, lipid and phospholipid levels, but increase in GSSG content were observed. It is concluded that thiol groups play an important role in antioxidation and detoxification of ROS as well as maintaining intracellular redox status. Thiol groups, thus, serve as defense mechanisms of sperm cells to fight against oxidative stress. In addition, all doses of FeAA cause leakage of lipids and phospholipids from the bull sperm membranes. (C) 2007 Elsevier B.V. All rights reserved.