Age-related changes in the induction of DNA polymerases in rat liver by gamma-ray irradiation

作者：Kaneko T^*; Tahara S; Tanno M; Taguchi T

来源：Mechanisms of Ageing and Development, 2002, 123(11): 1521-1528.

DOI：10.1016/S0047-6374(02)00119-7

• aging
• DNA repair
• oxidative damage
• 8-oxo-2 '-deoxyguanosine
• DNA polymerase
• PCNA

DNA polymerase activities related to DNA repair were examined in the livers of young (6-month-old) and aged (27-month-old) rats irradiated with gamma-rays. The activity of DNA polymerase a was little changed in the livers Of gamma-ray irradiated rats, while DNA polymerases beta and gamma were induced in the livers of young and aged rats exposed by gamma-ray irradiation. These enzymes were induced from 2 to 6 It after irradiation of young and aged rats, respectively, although the induction in aged rats was weak. DNA polyinerase beta activity in the livers of young rats irradiated with gamma-rays was 2-fold that in aged rats. Similarly, DNA polymerase gamma activity in the livers of young rats subjected to gamma-ray irradiation was 3-fold that in aged rats. The, induction of proliferating cell nuclear antigen (PCNA) in the livers of aged rats irradiated with gamma-rays was also delayed compared with young rats. These results indicate that the decline in repair activity in aged rats leads to the accumulation of oxidative damage and DNA mutations in aged tissues.

• 出版日期2002-9