Characterization of metalloproteinases in rat gastric tissues with acetic acid-induced ulcers.

To clarify the destruction of connective tissue in ulcerated regions, collagenase and gelatinolytic activities in homogenates of rat acetic acid-induced ulcers were examined. Gelatinolytic activity in the ulcerated regions was significantly higher than that in normal tissues. Collagenase, however, was not detectable. Gelatin-gel-electrophoresis showed that the gelatinolytic activity was due to several species, some of which crossreacted with a sheep anti-(rabbit prostromelysin) antibody. The H2-blocker, famotidine, significantly depressed the gelatinolytic activity in the ulcerated regions. Thus, both stromelysin and gelatinolytic enzymes may play important roles in the degradation of the basement membrane, especially type IV collagen.