title: Effect of aging on spontaneous micronucleus frequencies in peripheral blood of nine mouse strains: the results of the 7th collaborative study organized by CSGMT/JEMS.MMS. Collaborative Study Group for the Micronucleus Test. Environmental Mutagen Society of Japan. Mammalian Mutagenesis Study Group.
abstract: The spontaneous frequencies of micronucleated reticulocytes (MNRETs) were examined monthly over the life spans of animals belonging to nine mouse strains for the 7th collaborative study organized by the CSGMT/JEMS.MMS. Both sexes of the BDF1 strain and females of the A/J strain showed a statistically significant increase in mean spontaneous MNRET frequency in their last month of life, suggesting the possibility of strain-specific, age-dependent chromosomal instability. SAMP6/Tan, an accelerated senescence-prone strain, showed the same tendency, although it was not statistically significant. The other strains studied, ddY, CD-1, B6C3F1, SAMR1, and MS/Ae, did not show significant age-related differences in mean of MNRET frequencies. More extensive statistical analyses are underway, and the outcomes will be reported separately.
authors.affiliation: Toxicology Research Laboratories, Japan Tobacco Inc., Hatano.
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: M
authors.initials: M
authors.lastname: Taketomi
authors.forename: M
authors.initials: M
authors.lastname: Nakajima
authors.forename: M
authors.initials: M
authors.lastname: Kitazawa
authors.forename: H
authors.initials: H
authors.lastname: Shimada
authors.forename: S
authors.initials: S
authors.lastname: Itoh
authors.forename: M
authors.initials: M
authors.lastname: Igarashi
authors.forename: N
authors.initials: N
authors.lastname: Higashikuni
authors.forename: S
authors.initials: S
authors.lastname: Sutou
authors.forename: Y F
authors.initials: YF
authors.lastname: Sasaki
mesh_terms: D000375:Aging / Q000235:genetics*; D000818:Animals; D005260:Female; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D048629:Micronuclei, Chromosome-Defective / Q000235:genetics*; D012156:Reticulocytes / Q000648:ultrastructure*