[Lytic effect of human leukocytic proteases on gingival tissue]

Sections of human gingiva obtained in a cryostat have been treated with the granular fraction of human polymorphonuclear leucocytes (PMNs) at pH 3,6 and 7,3, as well as with the enzyme elastase (neutral protease) purified from the same cells. The sections treated by the enzymes have been compared to control serial sections incubated in the absence of enzyme or with the enzyme in the presence of a specific inhibitor. The results showed that the granular fraction at an acid pH seems to affect primarily the connective tissue, while the same fraction at a neutral pH, like the enzyme elastase exerts a preferential action upon epithelium structures.