Mori A, Liu J, Wang X, Kawai M
Department of Neuroscience, Okayama University Medical School, Japan.
Neurochem Int. 1994 Mar;24(3):201-7. doi: 10.1016/0197-0186(94)90076-0.
To study the mechanisms of free radical-induced brain damage and the antioxidant defense in the brain, we quantified the superoxide and hydroxyl radical scavenging effects of brain homogenate using electron spin resonance spectrometry. Brain homogenate was found to scavenge both superoxide and hydroxyl radicals in concentration-dependent fashion. Heat denaturation significantly decreased these scavenging effects. The ability of brain homogenate to scavenge free radicals implies that brain damage can be induced by free radicals since they are known to react virtually with any type of molecule such as nucleic acids, membrane lipids, and proteins in the brain. On the other hand, some molecules which can be regenerated or repaired after free radical scavenging are considered to be antioxidants which include both enzymatic and non-enzymatic antioxidants. Measurement of the decrease in antioxidant activity following heat denaturation suggests that the contribution of enzymatic antioxidants is about 20-40% in scavenging superoxide radicals and about 10-20% in scavenging hydroxyl radicals.
为了研究自由基诱导脑损伤的机制以及大脑中的抗氧化防御，我们使用电子自旋共振光谱法对脑匀浆的超氧化物和羟基自由基清除作用进行了定量。发现脑匀浆以浓度依赖的方式清除超氧化物和羟基自由基。热变性显著降低了这些清除作用。脑匀浆清除自由基的能力意味着自由基可诱导脑损伤，因为已知它们实际上能与大脑中的任何类型分子（如核酸、膜脂和蛋白质）发生反应。另一方面，一些在自由基清除后可被再生或修复的分子被认为是抗氧化剂，其中包括酶促抗氧化剂和非酶促抗氧化剂。热变性后抗氧化活性降低的测量结果表明，酶促抗氧化剂在清除超氧化物自由基中的贡献约为20 - 40%，在清除羟基自由基中的贡献约为10 - 20%。
