Increased sensitivity of lymphocytes from people over 65 to cell cycle arrest and chromosomal damage Academic Article Article uri icon


MeSH Major

  • Alzheimer Disease
  • Amyloid beta-Peptides
  • Dementia
  • Down Syndrome


  • Flow cytometry revealed that, in the presence of tritiated thymidine, a greater percentage of phytohemagglutinin-stimulated lymphocytes from old human donors were arrested in the G2 or M phase than were cells from young donors. Furthermore, lymphocytes from old donors showed significantly more chromosomal damage than did lymphocytes from young donors. Lymphocyte cultures from old or young donors not exposed to tritiated thymidine had the same percentage of cycling lymphocytes in G2 or M, although the number of lymphocytes stimulated by phytohemagglutinin to enter the cell cycle was significantly lower in cultures from old donors. Thus, the impaired incorporation of tritiated thymidine by phytohemagglutinin-exposed lymphocytes from old humans reflects both an impaired proliferative response to phytohemagglutinin and an increased sensitivity to the radiobiological effects of tritiated thymidine.

publication date

  • May 26, 1983



  • Academic Article


Digital Object Identifier (DOI)

  • 10.1126/science.6828861

PubMed ID

  • 6828861

Additional Document Info

start page

  • 1335

end page

  • 7


  • 219


  • 4590