title: Age-dependent modulation of tissue-specific repair activity for 3-methyladenine and O6-methylguanine in DNA in inbred mice.
abstract: 3-Methyladenine-DNA N-glycosylase (MAG) and O6-methylguanine-DNA methyltransferase (MGMT) activities were assayed in liver, lungs, brain and ovaries of female mice of two inbred stocks, C3Hf and C57BL/E, as a function of age. In addition to differences in the enzyme levels between the two stocks for each organ, the suckling animals (9-day-old) have consistently lower levels of both MAG and MGMT than young adults (7- or 8-week-old). While the MGMT levels in adults did not decrease with age, the MAG levels in 15- to 17-month-old animals were, in general, significantly lower than those in young adults. These results raise the possibility that the older animals are at a higher risk than young adults following exposure to alkylating mutagens.
authors.affiliation: University of Tennessee-Oak Ridge Graduate School of Biomedical Sciences.
authors.forename: W J
authors.initials: WJ
authors.lastname: Washington
authors.forename: R S
authors.initials: RS
authors.lastname: Foote
authors.forename: W C
authors.initials: WC
authors.lastname: Dunn
authors.forename: W M
authors.initials: WM
authors.lastname: Generoso
authors.forename: S
authors.initials: S
authors.lastname: Mitra
mesh_terms: D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000818:Animals; D045647:DNA Glycosylases; D004260:DNA Repair; D005260:Female; D008780:Methyltransferases / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D009153:Mutagens / Q000378:metabolism; D009699:N-Glycosyl Hydrolases / Q000378:metabolism*; D019853:O(6)-Methylguanine-DNA Methyltransferase; D012307:Risk Factors
chemical_list: D009153:Mutagens; D008780:Methyltransferases; D019853:O(6)-Methylguanine-DNA Methyltransferase; C021565:3-methyladenine-DNA glycosylase; D045647:DNA Glycosylases; D009699:N-Glycosyl Hydrolases