Biochemical Findings in Normal and Osteoarthritic Articular Cartilage. II. Chondroitin Sulfate Concentration and Chain Length, Water, and Ash Content*

Abstract

Osteoarthritic cartilage lesions show a decrease in chondroitin sulfate concentration and chain length and a decrease ratio of chondroitin sulfate to compounds containing neutral sgar, and keratin sulfate plus glycoprotein. This indicates the role of depolymerase such as hyaluronidase in the metabolic breakdown of chondroitin sulfate in these lesions. In vitro incubation with S35O4 and C14-acetate results in an increased specific activity of the chondroitin sulfate in osteoarthritic cartilage lesions, indicating turnover of the polysaccharide compared to normal cartilate sites. The water content of osteoarthritic cartilage is increased despite the decrease chondroitin sulfate concentration. The ash content of these lesions is not significantly altered. Comparison of normal specimens from individuals ranging in age from 30-80 yr. revealed no influence of age on the concentration or chain length of chondroitin sulfate, the concentration of compounds containing neutral sugar, the water content or the ash content of articular cartilage.