Changes of 8-hydroxydeoxyguanosine levels in rat organ DNA during the aging process

We investigated the accumulation of oxidative DNA damage during the aging process by using 8-hydroxydeoxyguanosine (8-OH-dG) as a marker. The 8-OH-dG is one of the oxidative DNA damage products and is supposed to be a critical factor in carcinogenesis involving oxygen radicals. The 8-OH-dG levels in the DNA of liver, kidney, brain, lung, and spleen were measured in male and female F344 rats 6- to 30-month-old. The 8-OH-dG levels in the liver and kidney DNA of male rats increased significantly with age, but did not change in brain, lung, and spleen. Similarly, the 8-OH-dG levels in the liver and kidney DNA of female rats significantly increased with age, while changes in the brain, lung, and spleen DNA were much smaller. These results indicate that the accumulation of oxidative DNA damage during the aging process varies among organs, with slight sex difference.