In-vitro studies of aging

Research has conclusively established that normal diploid cells in culture have a limited replicative life span, and that cells from adult organisms have a shorter life span than cells from young organisms or embryos. Although it is unlikely that death of the organism is caused by failure in cellular proliferative capacity, the changes that accompany alterations in proliferative capacity may play significant roles in organismic aging. The causes of the decreased proliferative vigor of cells with age are not known, but one factor may reside in the fact that with increasing in-vitro or donor age, cells become less able to respond to mitogens. Additionally, it is known that proliferative capacity of cells in culture is under genetic control, although this control can be modified by environmental factors. Thus, although the precise relationship between in-vitro and in-vivo aging remains undefined, advances in technology give hope that a delineation of this relationship may in time be achieved and, with it, an increased understanding of organismic senescence.