Effect of 5-bromodeoxyuridine on expression of cultured chondrocytes grown in vitro.

Exposure of cultured cartilage cells to 5-bromodeoxyuridine results in a rapid loss of the ability to synthesize the chondroitin 4-sulfate-protein complex characteristic of the extracellular matrix of differentiated cartilage. UDP-glucose dehydrogenase, UDP-N-acetyl hexosamine 4-epimerase and the enzyme system responsible for catalyzing 3'-phosphoadenosine-5'-phosphosulfate synthesis all progressively decline in activity, while several other cellular processes seem unaffected. However, there are marked morphological changes which may be associated with plasma membrane components or the synthesis of the protein-polysaccharide complex.