Collagenase and Periodontal Diseases: A Review

Collagen is the predominant organic con-stituent of bone, cementum, periodontal membranes, and gingiva. For this reason, it is the major protein destroyed during the course of periodontal diseases. Although for many years degradation of collagen has been known to occur as part of the process of periodontitis, demonstration of specific col-lagenase, derived from periodontal tissues and capable of acting at physiologic pH and ionic strength, has been recent.1-6 Discovery of the enzyme required the use of a tissue culture system. Previous investigators search-ing for collagenase in vertebrate tissues had examined homogenates without success.7'8 Collagenase Detection Collagenase in man was first detected be-cause of a zone of collagen lysis surrounding cultured gingival tissues. Despite the use of methods to curtail and eliminate bacterial contamination, it was imperative during ini-tial stages of investigations to determine whether the collagenolytic activity observed was derived from gingival tissues or from an associated microbial flora. Several subse-quent investigations provided evidence that excluded microorganisms as a source for the observed collagenase. The data noted were as follows: (1) Neither macroscopic nor microscopic evidence of colonies of micro-organisms in association with tissues sur-rounded by zones of lysis was obtained.2 (2) Aerobic and anaerobic cultures of tissues surrounded by zones of lysis were negative.2 (3) Cultured gingiva from both germfree and conventional rats produced zones of col-lagen lysis.9 (4) Fragments of collagen result-ing from enzymatic hydrolysis were similar to those formed from vertebrate (tadpole and human synovial) collagenase, rather than to those formed from a microbial col-lagenase.6,0- 16