[Under-hydroxylation of collagen synthesized by cultured fibroblasts].

The collagen secreted by dermal fibroblast cell cultures, previously labelled with 3H-proline, was extracted and purified by carboxymethyl cellulose. The ratio of hydroxyproline to proline showed that the collagen produced by cell cultures may be under-hydroxylated in comparison to the ratio observed in the types of collagen extracted from human skin. Then, it is concluded that it is not sufficient to determine only the hydroxyproline content for a collagen biosynthesis study in cell cultures. This low hydroxyproline content may explain the rapid catabolism of a part os newly synthetized collagen in vitro.