Age-related changes in g0-g1 transition and proliferative capacity of mitogen-stimulated murine spleen cells.

The early kinetics of mitogen-stimulated of mitogen-stimulated spleen cells from young adult and aged NMRI mice were investigated. Using RNA synthesis as measured by cytofluorometry by cytofluorometry and 3H-leucine and 3H-thymidine incorporation as parameters, it was apparent that age-related changes occur at different levels during mitogen stimulation. First, in aged mice fewer cells per 10(6) spleen cells are being activated by mitogen, and, second, fewer of the activated lymphocytes will proliferate. However, the cells which initiate synthesis of RNA, protein, and DNA apparently behave in identical manners, chronologically, as cells from young adult mice.