Figure 4.

Basal proteoglycan production. Fibroblasts were incubated for 24 hours in cell medium containing 0.4% serum, and proteoglycan content in medium was determined by the ability to incorporate [S³⁵]-sulphate into glycosoaminoglycan side chains. Values were related to protein concentration in the respective cell layers to account for variability in cell numbers. Individual proteoglycans were separated and quantified on SDS-PAGE gels to determine the contribution of each to the total proteoglycan content. Graph A shows production of versican, B perlecan, C biglycan, and D decorin. * P < 0.05, ** P < 0.01, ⁺ P < 0.05, ⁺⁺ P < 0.01 and ⁺⁺⁺ P < 0.001.