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.