[Changes of acid phosphatase in the gastric mucosa during ulcerogenesis]

Experiments were performed on white rats with experimental acetate ulcer of the stomach and intestine. At the height of destruction of gastric mucosa tissue (60 minutes from the onset of ulcer formation) a consistent increase in acid phosphatase secretion was recorded. This process was accompanied, as a rule, by significant elevation of proteolytic activity (pH 6.5-7.0) in tissue extract obtained from the affected area. It is suggested that the increased proteolytic activity observed at pH 6.5-7.0 in the tissue extract from the ulcerous area is most likely related to the release of lysosomal proteases at the height of tissue destruction. It thus appears that ulcer of the gastric mucosa induced by acetic acid application is determined by interstitial proteolytic activity of cathepsins that are released during the destruction of lysosomal membranes.