Increase in levels of serum keratan sulfate following cartilage proteoglycan degradation in the rabbit knee joint

Abstract
Following injection of chymopapain into a single knee joint in rabbits, serum keratan sulfate levels rose sharply and remained elevated for at least 48 hours before returning to preinjection levels. These changes were accompanied by depletion of proteoglycans from articular cartilage in the injected joint. We conclude that serum keratan sulfate levels rise predictably following acute loss of proteoglycan from a single joint.