Age-associated change of 8-hydroxyguanine repair activity in cultured human fibroblasts.

8-hydroxyguanine (8-OH-Gua) is a major oxidative DNA damage product. Its repair activity was determined in the human fibroblast cell line, TIG-3, during the aging process. The repair activity increased in the first part of the aging process and decreased in the latter part. The highest repair activity was observed at the age of 30 PDL. These results suggest that the defense capacity for replication errors due to oxidative DNA damage increases greatly when the cells are rapidly dividing.