Alterations in the quality of collagen and activities of hydrolases in the gingival connective tissues of patients with periodontitis.

Abstract

The biochemical changes in gingival connective tissue components under periodontitis were studied by determining the alterations in the quality of colla gen and the activities of acid and neutral hydrolases in surgical specimens obtained from pati ents.1) Soluble protein and dialyzable hydroxyproline contents were markedly increased in diseased gingivae as compared with clinically normal gingivae. Both salt-soluble and acid-soluble collagen in diseased tissues increased 2 or 3 fold over those in nor mal tissues.2) There were no significant differences in acid hydrolas e activities between diseased and normal tissues. Cathepsin B1 and collagenolytic activities which were measured at neutral pH increased markedly in diseased gingivae. On the other hand, no significant difference in cathepsin G activity was noted between normal and diseased tissues.These findings suggested that cathepsin B1 and collagenase played an important role in the alteration of connective tissue components under periodontitis.