Sridevi N, Venkataraman P, Senthilkumar K, Krishnamoorthy G, Arunakaran J
Department of Endocrinology, Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani, Chennai 600 113, India.
Biomed Pharmacother. 2007 Aug;61(7):435-40. doi: 10.1016/j.biopha.2007.03.003. Epub 2007 Apr 3.
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.
多氯联苯（PCBs）是一类广泛分布且在环境中持久存在的有机化合物。多氯联苯具有多种毒理学效应，包括神经毒性。维生素E（α-生育酚）是一种重要的脂溶性抗氧化剂，存在于细胞膜的特殊区域。维持中枢神经系统（CNS）细胞的信号传导活动需要大量能量。控制细胞器膜和质膜上离子梯度的膜蛋白似乎特别容易受到氧化诱导的变化影响。本研究的目的是确定维生素E对Aroclor 1254诱导的大鼠脑区膜结合ATP酶调节的保护作用。一组大鼠接受玉米油作为载体，持续30天作为对照。另一组大鼠腹腔注射剂量为2mgkg(-1) bwday(-1)的Aroclor 1254，持续30天。一组大鼠在腹腔注射Aroclor 1254的同时口服维生素E（50mgkg(-1) bwday(-1)），持续30天。30天后，对动物实施安乐死并解剖大脑，获取下丘脑和海马体以测定以下参数。测定过氧化氢（H2O2）、脂质过氧化（LPO）以及Na+K+-ATP酶、Ca2+-ATP酶和Mg2+-ATP酶的活性。还测定了还原型谷胱甘肽（GSH）水平。在多氯联苯处理动物的选定脑区中，所有酶的活性均降低，同时H2O2和LPO增加。在暴露于多氯联苯的动物中同时进行维生素E治疗可显著恢复所有参数。这些结果表明，氧化应激参与了多氯联苯（Aroclor 1254）对选定脑区膜结合ATP酶的抑制作用。α-生育酚通过降低氧化应激来对抗多氯联苯诱导的神经毒性。
