RELATIONSHIP BETWEEN DONOR AGE AND THE REPLICATIVE LIFE-SPAN OF HUMAN-CELLS IN CULTURE - A REEVALUATION

Normal human diploid fibroblasts have a finite replicative lifespan in vitro, which has been postulated to be a cellular manifestation of ag ing in vivo. Several studies have shown an inverse relationship betwee n donor age and fibroblast culture replicative lifespan; however, in a ll cases, the correlation was weak, and, with few exceptions, the heal th status of the donors was unknown. We have determined the replicativ e lifespans of 124 skin fibroblast cell lines established from donors of different ages as part of the Baltimore Longitudinal Study of Aging , All of the donors were medically examined and were declared ''health y,'' according to Baltimore Longitudinal Study of aging protocols, at the time the biopsies were taken. Both long- and short-lived fell line s were observed in all age groups, but no significant correlation betw een the proliferative potential of the cell lines and donor age was fo und. A comparison of multiple cell lines established from the same don ors at different ages also failed to reveal any significant trends bet ween proliferative potential and donor age. The rate of [H-3]thymidine incorporation and the initial rates of growth during the first few su bcultivations were examined in a subset of cell lines and were found t o be significantly greater in fetal lines than in postnatal lines, Cel l lines established from adults did not vary significantly either in i nitial growth rate or in [H-3]thymidine incorporation, These results c learly indicate that, if health status and biopsy conditions are contr olled, the replicative lifespan of fibroblasts in culture does not cor relate with donor age.