title: Influence of donor age on the cytotoxicity and mutagenicity of ethylnitrosourea in cultured human T-lymphocytes.
abstract: The effects of age on the cytotoxicity and mutagenicity of N-ethyl-N-nitrosourea (ENU) in human peripheral blood T-lymphocytes were investigated using colony-forming assay in vitro. ENU was shown to induce a dose-dependent increase in cell killing and in mutation frequencies (MF). No significant correlation between age and ENU-induced 6-thioguanine-resistant (TGr) MF at the hypoxanthine phosphoribosyl transferase (HPRT) locus of the X-chromosome was found after treatment with the same concentration of ENU (1 mM or 2 mM). There were also no significant differences among different donor age groups and the sensitivity parameters for exposure to ENU. As X-rays, the cytotoxic and mutagenic effects of ENU in cultured human T-lymphocytes appear not to be associated with age. These results suggest that the repair of mutagen-induced DNA lesions does not decline with age. Such knowledge has implications for risk assessment and protection against environmental mutagens.
authors.affiliation: Department of Radiation Biology and Health, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Mei
authors.forename: N
authors.initials: N
authors.lastname: Kunugita
authors.forename: S
authors.initials: S
authors.lastname: Nomoto
authors.forename: A
authors.initials: A
authors.lastname: Ootsuyama
authors.forename: T
authors.initials: T
authors.lastname: Norimura
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging / Q000502:physiology*; D000477:Alkylating Agents / Q000633:toxicity*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004260:DNA Repair / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005038:Ethylnitrosourea / Q000633:toxicity*; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D008875:Middle Aged; D009153:Mutagens / Q000633:toxicity*; D013601:T-Lymphocytes / Q000187:drug effects* / Q000201:enzymology; D014960:X Chromosome
chemical_list: D000477:Alkylating Agents; D009153:Mutagens; D007041:Hypoxanthine Phosphoribosyltransferase; D005038:Ethylnitrosourea