DNA status in brain and heart as prominent co-determinant for life span? Assessing the different degrees of DNA damage, damage susceptibility, and repair capability in different organs of young and old mice.

摘要: Abstract Alkaline filter elution has been modified by a freeze-grinding step that allows the evaluation of DNA status whole tissue, including mouse tail cross-sections, with only small additional artefacts. Four to seven different organs from individually coordinated female NMRI mice, rated as young when 2–3 months, and old 24–27 age, have used. Tissues individual mice differ significantly in their status. Alkali-labile sites are relatively rare amount young. They show significant increases old, reaching highest values brain heart. Proteinase K dependant DNA-protein cross-links not prominent nor they increased age some organs, except damage susceptibility was measured after application 3.5 μM nitoquinolin-N-oxide 15 mg fresh tissue pieces for 90 min. The susceptibilty is large varying wide ranges organs. Upon 3 h post-exposure incubation full medium all samples showed repair, reach nearly complete repair lung, while generally, decreased. In heart it even near zero. This together high alkali-labile protein-DNA cross-linking suggests these two may act pacemakers play role co-determinants life span species.