Effects of superoxide anion and granulocytes on in situ gastric mucosa of rat in the development of experimental acute gastric mucosal lesions

Abstract

Recently, we demonstrated that O^-₂ generated in in situ tissues could be detected with cypridina luciferin analog (CLA) as a chemiluminescence probe and a sensitive photon counting system as the detector of chemiluminescence. With these, we examined whether or not O^-₂ generates in in situ gastric mucosa of rats under the conditions to induce experimental acute gastric mucosal lesions (AGMLs) and ischemia-reperfusion of gastric mucosa.
The results obtained were as follows: (1) O^-₂ generated by activated granulocytes was detected at a time at which the gastric mucosal blood flow had already decreased in experimental AGMLs and the ischemia-reperfusion system. (2) The edema and erosion formation occurred in the fundic gastric mucosa due to granulocyte mediation. (3) The edema formation was inhibited by a continuous infusion of superoxide dismutase at a time at which the O^-₂ was being generated, but the erosion formation was not inhibited in the same experiment.
These results indicate that granulocyte activation, which induces the tissue injury, occurs in the gastric mucosa in an early developmental phase in AGMLs due to the injury to the circulation, and that O^-₂ is related to the edema formation.