增龄对SAM小鼠脑线粒体DNA氧化损伤的影响

目的探讨增龄对SAM小鼠脑线粒体DNA(mtDNA)缺失、活性氧自由基水平及脑组织总抗氧化能力的影响。方法SAM-P／8和SAM-R／1小鼠分别分为三组幼年组(0．5月龄)、青年组(2月龄)和老年组(12月龄)各6只。用PCR方法测定脑组织线粒体DNA缺失、用化学发光法测定总抗氧化能力及活性氧自由基。结果随增龄，SAM—P／8小鼠脑组织线粒体DNA缺失增加，线粒体活性氧自由基水平升高，脑组织总抗氧化能力下降。结论随增龄，SAM-P／8小鼠脑组织氧化损伤增加，可能是导致其记忆学习障碍的原因之一。

Effect of aging on cerebral mitochondrial DNA oxidative damage of SAM mice

Objective To explore the effect of aging on cerebral mitochondrial (mt) DNA deletions, active oxygen radical level and total anti-oxidization ability of brain tissues. Methods SAM-P/8 and SAM-R/1 mice were respectively divided into three groups, i.e. infant group (0.5 month-old), youth group (2 month-old) and senior group (12 month-old), with six mice in each group. Cerebral mtDNA deletions were determined by PCR while total anti-oxidization ability and active oxygen radical levels were detected by chemical luminescent method. Results With aging, mtDNA deletions in the brain tissue of SAM-P/8 mice increased with an elevated level of mt active oxygen radical level and lowered total anti-oxidization ability. Conclusions The increase of oxidative damage in brain tissue of SAM-P/8 mice with ageing might be one of the causes resulting in memory learning impediment.