IDENTIFICATION OF MATRIX METALLOPROTEINASES AND THEIR INHIBITOR IN THE ARTICULAR DISC OF THE CRANIOMANDIBULAR JOINT OF THE RABBIT

Connective tissue cells synthesize and secrete matrix metalloproteinas es (MMPs), a family of matrix-degrading enzymes (comprising collagenas es, gelatinases and stromelysins), which are capable of degrading all the constituent molecules of connective tissues at physiological pH. T his investigation documents the synthesis and distribution of MMPs and their inhibitor TIMP-1 (tissue inhibitor of metalloproteinases-1) in the developing articular disc of the craniomandibular joint of the rab bit using indirect immunofluorescence microscopy. Cells of the disc sy nthesized all three classes of MMPs as well as TIMP-1 in all regions o f the disc at all stages examined. MMPs and TIMP-1 were detected as br ight intracellular accumulations probably within Golgi vesicles and as occasional diffuse, matrix-bound deposits. These results suggest that MMP-mediated matrix remodelling is a prominent feature of growth in c raniomandibular joint disc. Copyright (C) 1996 Elsevier Science Ltd.