Increased chromosomal instability in lymphocytes from elderly humans.
Lymphocytes from young and old donors were incubated with PHA for 96 h and exposed to [3H]Tdr during the last 24 h of culture. Comparable amounts of [3H]Tdr were incorporated into chromosomes of old and young lymphocytes as measured by autoradiography of metaphase chromosomes. However, chromosomal damage and cell-cycle arrest were far greater in lymphocytes from old as compared to young humans. The frequency of chromosome breaks, fragments, exchange figures and dicentric chromosomes induced by [3H]Tdr was greater in cultures from old than in cultures from young humans. Lymphocytes from old donors exposed to 20 microM BrdU during the last 24 h of culture showed significantly more sister-chromatid exchanges than did lymphocytes from young donors. These data suggest that chromosomes in lymphocytes from old donors express more damage after exposure to [3H]Tdr or BrdU than do chromosomes in lymphocytes from young donors.
D000328:Adult; D000368:Aged; D000375:Aging; D002453:Cell Cycle; D002869:Chromosome Aberrations; D002875:Chromosomes / Q000502:physiology*; D004260:DNA Repair; D006801:Humans; D008214:Lymphocytes / Q000502:physiology*; D012854:Sister Chromatid Exchange; D013936:Thymidine / Q000633:toxicity; D014316:Tritium
D014316:Tritium; D013936:Thymidine