A cartilage‐derived growth factor enhances hyaluronate synthesis and diminishes sulfated glycosaminoglycan synthesis in chondrocytes

Abstract

Cartilage‐derived growth factor purified to homogeneity by affinity chromatography on columns of heparin‐Sepharose was mitogenic for early passage bovine fetal chondrocytes. Hyaluronate and sulfated glycosaminoglycan synthesis in these cells was analyzed by differential enzymatic digestion of the glycosaminoglycans labeled with [¹⁴C] glucosamine or [³⁵S]. It was found that chondrocyte proliferation was accompanied by about a four‐fold increase in hyaluronate synthesis over a two‐day period, while the synthesis of sulfated glycosaminoglycans decreased by about 2‐fold. Chromatographic analysis of the sulfated glycosaminoglycans showed decreases in chondroitin 4 and 6 sulfates. It was concluded from these results that cartilage‐derived growth factor was a proliferative factor for chondrocytes and differed from the somatomedins.