Synovial membrane-cartilage interactions--the role of serine proteinase inhibitors in interleukin-1 mediated degradation of articular damage.

Using a peritoneal macrophage/articular cartilage co-culture system, it was shown that the serine proteinase inhibitor derived from human articular cartilage modulated the release of 35S-labelled proteoglycan into media in a concentration dependent manner. Since the cartilage inhibitor fractions used were free of metallo-proteinase and cysteine proteinase inhibitory activity, but strongly inhibited serine proteinases, it was suggested that such enzymes may be implicated in the activation of latent metallo-proteoglycanases produced by chondrocytes on exposure to IL-1.