Age-Associated Changes in the DNA of Mouse Tissue

Abstract
The template activity of DNA with calf thymus DNA polymerase has been studied in sections of fixed brain, liver, and heart tissues from young and senescent mice. The enzyme catalyzed greater incorporation of deoxyribonucleotide monophosphates into nuclei of old mouse neurons, astrocytes, Kupffer cells, and heart muscle fibers. The results are interpreted as the accumulation of DNA strand breaks with aging.