The in vivo levels of DNA alkylation products in human lymphocytes are not age dependent: an assay of 7-methyl- and 7-(2-hydroxyethyl)-guanine DNA adducts.
Endogenous DNA damage is assumed to be a major contributor to aging and cancer. This study compares the steady-state levels of 7-methyl- and 7-(2-hydroxyethyl)-guanine DNA adducts in lymphocytes isolated from the younger (mean age 39.8 years) and the older (mean age 82.8 years) healthy subjects. Using a 32P-post-labelling method, these adducts were measured in lymphocyte DNA from a total of 34 subjects. The results show that the amount of both 7-methyl- and 7-(2-hydroxyethyl)-guanine adducts in the younger age group was similar to that in the older age group. Our findings show that at steady-state the levels of DNA alkylation products are independent of age, suggesting that endogenous DNA damage, through methylation or lipid peroxidation, and the repair of such damage may not be deficient in lymphocytes of older individuals.
Zhao
Chunyan
C
Department of Biosciences at Novum, Karolinska Institute, 14157 Huddinge, Sweden. chunyan.zhao@cnt.ki.se
Hemminki
Kari
K
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002851:Chromatography, High Pressure Liquid; D018736:DNA Adducts; D004249:DNA Damage; D004260:DNA Repair; D006147:Guanine / Q000031:analogs & derivatives* / Q000378:metabolism*; D006801:Humans; D015227:Lipid Peroxidation; D008214:Lymphocytes / Q000187:drug effects* / Q000378:metabolism*; D008745:Methylation; D008875:Middle Aged; D013997:Time Factors
D018736:DNA Adducts; C035018:N(7)-hydroxyethylguanine; D006147:Guanine; C008450:7-methylguanine