Effect of IL-1 on total PH-20 production and hyaluronidase secretion by connective tissue cell lines. Chondrocytes, synoviocytes, and fibroblast cell layers either were not stimulated or were stimulated with IL-1 at a concentration of 5 ng/ml. At the end of the stimulation period, the PH-20 proteins present in conditioned media and Triton X-100-extracted cell layers were purified by the immunoaffinity gel and quantified using the commercial BCA assay. Upper panel: total amount of PH-20 (cell layer + corresponding medium) expressed as the relative percentage of the total amount of proteins present in the Triton-X-100 cell layer extract. Lower panel: relative percentage of the total PH-20 liberated into the conditioned medium. P = P value as assessed by paired t-test.