A serum factor capable of stimulating hyaluronic acid synthesis in cultured rat fibroblasts

Abstract
Calf serum as well as rat and mouse sera has a factor that stimulates hyaluronic acid synthesis in cultured rat fibroblasts. Such a factor was partially purified from calf serum and characterized. It has a molecular weight of approximately 150,000. The activity of the factor is lost by treatment with pronase and by periodate oxidation. It is suggested, therefore, that the factor is a glycoprotein. Its susceptibility to α‐mannosidase and affinity for Con A‐Sepharose may suggest that the factor contains a mannose residue(s) which is essential for the activity to induce hyaluronic acid synthesis.