Abstract

A mouse fibroblast cell line, B82, was treated with H2O2 for examination of the damage to mtDNA and to respiratory function. The results showed that the copy numbers of intact mtDNA molecules reduced rapidly during 15 minutes H2O2 treatment, while reduction of respiratory function was observed after 24 hours. The presence of such a time lag, as observed between the damage to mtDNA and respiratory function, suggested that respiration defects were not due to direct damage to polypeptides consisting of respiratory enzyme complexes, but resulted from damage to mtDNA. Moreover, both the reduced amounts of intact mtDNA and the reduced activity of respiratory enzymes were restored in 2-5 days, suggesting that the mtDNA damage was reversible, and thus were not fixed as pathogenic mutations. Verf.-Referat