Chondroitin sulphates and embryonic chick skin fibroblast proliferation

We have investigated the action of sulphated glycosaminoglycans (GAGs) upon primary 11-day chick embryo skin fibroblasts cultured for various periods of time in the presence or absence of fetal calf serum (FCS). Chondroitin 4- and 6-sulphate (CS) added to serum supplemented medium provoked a decrease in DNA synthesis both in sparse and crowded cultures only at high concentrations (250 micrograms/ml). Synthesis of endocellular and secreted proteins was not affected. In contrast, CS administered to fibroblasts for 24 h in serum-free medium stimulated DNA synthesis. We postulate that the CS stimulating effect seen in serum-free cultures might be antagonized by peptide regulators of cell growth normally present in serum.