Nakao N, Grasbon-Frodl E M, Widner H, Brundin P
Department of Physiology and Neuroscience, University of Lund, Sweden. p4
Neuroscience. 1996 Jul;73(1):185-200. doi: 10.1016/0306-4522(96)00034-6.
It has been suggested that oxidative stress plays an important role in mediating excitotoxic neuronal death. We have therefore investigated the protective effects of antioxidants against excitotoxic injury in the rat on striatal neurons both in vitro and in vivo. In the first part of the study, we determined whether two different types of antioxidants, the spin trapping agent, alpha-phenyl-tert-butyl nitrone and an inhibitor of lipid peroxidation, U-83836E, could protect cultured striatal neurons against either hypoglycemic injury or N-methyl-D-aspartate-induced excitotoxicity. Dopamine- and cyclic AMP-regulated phosphoprotein, which is enriched in medium-sized spiny neurons, was chosen as a marker for striatal neurons. alpha-Phenyl-t-butyl nitrone and U-83836E both significantly reduced cell death induced by these insults as indicated by an increased number of surviving dopamine- and cyclic AMP-regulated phospho-protein-positive neurons. The two antioxidants also promoted the survival of cultured striatal neurons grown at low cell density under serum-free culture conditions. In an in vivo experiment systemically administered alpha-phenyl-t-butyl nitrone exerted neuroprotective effects in the rat striatum following injection of the excitotoxin quinolinic acid. Apomorphine-induced rotation tests revealed that alpha-phenyl-t-butyl nitrone-treated animals were significantly less asymmetric in their motor behavior than control rats. Treatment with alpha-phenyl-t-butyl nitrone significantly reduced the size of the quinolinic acid-induced striatal lesions, as assessed by the degree of sparing of dopamine- and cyclic AMP-regulated phospho-protein-positive and nicotinamide adenine dinucleotide phosphate-diaphorase-positive neurons, and of microtubule-associated protein-2-immunorective areas. Furthermore, lesion-induced morphological changes in the substantia nigra pars reticulate, i.e. loss of dopamine- and cyclic AMP-regulated phosphoprotein-positive afferent fibers and atrophic changes due to transsynaptic degeneration, were also less extensive in the alpha-phenyl-t-butyl nitrone-treated animals. The results support the hypothesis that oxygen-free radicals contribute to excitotoxic neuronal injury. The in vivo cytoprotective effects of alpha-phenyl-t-butyl nitrone against striatal excitotoxic lesions suggest that antioxidants could be used as potential neuroprotective agents in Huntington's disease, which has been suggested to involve excitotoxicity.
有人提出氧化应激在介导兴奋性毒性神经元死亡中起重要作用。因此，我们研究了抗氧化剂对大鼠纹状体神经元体外和体内兴奋性毒性损伤的保护作用。在研究的第一部分，我们确定了两种不同类型的抗氧化剂，自旋捕获剂α-苯基叔丁基硝酮和脂质过氧化抑制剂U-83836E，是否能保护培养的纹状体神经元免受低血糖损伤或N-甲基-D-天冬氨酸诱导的兴奋性毒性。选择在中等大小棘状神经元中富集的多巴胺和环磷酸腺苷调节磷蛋白作为纹状体神经元的标志物。α-苯基叔丁基硝酮和U-83836E均显著减少了这些损伤诱导的细胞死亡，这表现为存活的多巴胺和环磷酸腺苷调节磷蛋白阳性神经元数量增加。这两种抗氧化剂还促进了在无血清培养条件下低细胞密度生长的培养纹状体神经元的存活。在体内实验系统中，全身给予α-苯基叔丁基硝酮在注射兴奋性毒素喹啉酸后对大鼠纹状体发挥神经保护作用。阿扑吗啡诱导的旋转试验表明，α-苯基叔丁基硝酮处理的动物在运动行为上的不对称性明显低于对照大鼠。通过多巴胺和环磷酸腺苷调节磷蛋白阳性和烟酰胺腺嘌呤二核苷酸磷酸黄递酶阳性神经元以及微管相关蛋白-2免疫反应区的保留程度评估，α-苯基叔丁基硝酮处理显著减小了喹啉酸诱导的纹状体损伤的大小。此外，在α-苯基叔丁基硝酮处理的动物中，损伤诱导的黑质网状部形态学变化，即多巴胺和环磷酸腺苷调节磷蛋白阳性传入纤维的丧失以及由于跨突触变性引起的萎缩性变化，也不那么广泛。结果支持了氧自由基导致兴奋性毒性神经元损伤的假说。α-苯基叔丁基硝酮对纹状体兴奋性毒性损伤的体内细胞保护作用表明，抗氧化剂可作为亨廷顿病潜在神经保护剂，该病已被认为涉及兴奋性毒性。
