Cartilage and osteoarthrosis: changes of collagen and proteoglycans.

The authors discuss changes of proteoglycans and collagen in osteoarthrotic cartilage, based on their own results. During osteoarthrosis the proteoglycan molecule diminishes in size, mainly due to a diminution of the carbohydrate portion. The diminution of binding glycoprotein leads to changes in the interaction with hyaluronic acid. Collagen is more soluble and has a reduced resistance to proteolytic enzymes. In the osteoarthrotic cartilage also collagen type I and III is present.