COLLAGENASE IN SJOGRENS-SYNDROME

Objective-To study collagenase production in labial salivary glands in patients with Sjogren's syndrome (SS). Methods-Collagenases were loca lised in labial salivary glands by immunohistochemistry. Collagenase a ctivity against triple helical type I collagen monomers in stimulated saliva was measured using sodium dodecyl sulphate polyacrylamide gel e lectrophoresis and laser densitometry; tissue inhibitor metalloprotein ase (TIMP) was measured by enzyme Linked immunosorbent assay. Results- Cells containing collagenase of matrix metalloproteinase (MMP)-1 type were more frequent and more intensely staining in SS than in healthy g lands. Only SS saliva contained functional enzyme (11.7 (6.8) x 10(-6) IU/1). Cells containing MMP-8 type neutrophil collagenase were not fo und in situ, which was in accordance with sialochemical findings/doxyc ycline inhibition studies. TIMP was found in both SS and normal saliva . Conclusions-Fibroblast, but not neutrophil type, collagenase is synt hesised, secreted, and subsequently activated, but is not inhibited by TIMP in labial salivary glands or saliva in SS. Collagenase may destr oy glandular and salivary duct tissue and perturb factors influencing the morphogenetic extracellular matrix.