Oxidative stress modulates membrane bound ATPases in brain regions of PCB (Aroclor 1254) exposed rats: protective role of alpha-tocopherol.

Polychlorinated biphenyls (PCBs) are a class of widely dispersed and environmentally persistent organic compounds. PCBs exhibit a wide range of toxicological effects including neurotoxicity. Vitamin E (alpha-tocopherol) is an important lipid soluble antioxidant placed in a special region of membranes. Large amounts of energy are required to maintain the signaling activities of the cells in the central nervous system (CNS). Membrane proteins that control ion gradients across organellar and plasma membranes appear to be particularly susceptible to oxidation-induced changes. The aim of this study was to determine the protective role of vitamin E on Aroclor 1254 induced modulation in membrane bound ATPases in brain regions of rats. One group of rats received corn oil as vehicle for 30days as control. The other group of rats were administered Aroclor 1254 at a dose of 2mgkg(-1) bwday(-1) intraperitoneally for 30days. One group of rats received vitamin E (50mgkg(-1) bwday(-1)) orally simultaneously with Aroclor 1254 for 30days. After 30days, the animals were euthanized and the brain was dissected to hypothalamus and hippocampus to determine the following parameters. Hydrogen peroxide (H2O2), Lipid peroxidation (LPO) and the activities of Na+K+-ATPase, Ca2+-ATPase and Mg2+-ATPase were determined. Reduced glutathione (GSH) level was also determined. Activities of all the enzymes were decreased while an increase in H2O2 and LPO were observed in selected brain regions of PCB treated animals. Simultaneous vitamin E treatment in PCB exposed animals restored all the parameters significantly. These results suggest that oxidative stress is involved in the inhibitory effect of PCB (Aroclor 1254) on membrane bound ATPases in selected brain regions. alpha-tocopherol acts against PCB induced neurotoxicity by decreasing oxidative stress.