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Synopsis The normal dermal human fibroblastic cell (NDHF) was used to determine a cellular ageing pattern. Cells were cultured in monolayers until the 30th passage. First of all, the following cell growth characteristics were studied: growth rate, fluorimetric DNA determination, DNA repair after UV irradiation. Secondly, metabolism characteristics were examined: lysosomal enzymatic activity and type I and III collagen biosynthesis. Strains were obtained from 10,30,43 and 69-year-old donors to favour a comparison between in vitro and in vivo ageing. Cell growth ability is modified in vitro only for the oldest strain which shows a significant decrease in the cellular density at the 30th passage. The DNA rate and its repairing ability are not changed by in vitro ageing whatever the strain age. Lysosomal activity increases during in vitro ageing whereas the collagen I synthesis decreases. In vitro proliferating potentialities do not reflect in vivo ageing. On the other hand, in this study, metabolic potentialities evolve in the same way in vitro as in vivo and could be a good enough pattern to select anti-ageing products.