Fibrinolytic activity of gingival epithelium

Specimens of both human and animal gingivae were examined by fibrinolytic autography and all showed lysis over the gingival pocket epithelium, lysis never occurring over oral gingival epithelium. Epithelium separated from the connective tissue also showed fibrinolytic activity confined to the pocket epithelium. Examination of human gingival crevice washings showed fibrinolysis over some nucleated squamous epithelial cells as well as over anuclcated cell fragments. Although ihe neutrophil leucocytes in crevicular washings have fibrinolytic activity, this activity does not compare with that of the epithelium. The fibrinolytic activity of gingival pocket epithelium may be important in the pathogenesis of gingivitis and periodontitis, particularly due to the ability of plasmin lo activate complement.