Carrageenin-induced arthritis. II. Effect of intraarticular injection of carrageenin on the synthesis of proteoglycan in articular cartilage.

An inflammation of the periarticular tissue induced by the intraarticular injection of carrageenin caused a 40-75% decrease in the rate of proteoglycan synthesis in the articular cartilage. This decrease was determined both in vitro and in vivo. Provided that the collagen network of the cartilage was not disrupted, the chondrocytes were able to recover this synthetic ability and exhibited rates of synthesis above those of the controls. This ability resulted in a net replacement of the proteoglycan lost during the initial period of inflammation.