The interrelationships between the lipid peroxidation, superoxide dismutase activity, development of gastric H+ secretion and gastric mucosal damage produced by intragastric administration of aspirin in pylorus-ligated rats.

Gastric mucosal damage of pylorus-ligated rats was induced by the intragastric administration of aspirin at 200 mg/kg at the time of ligation. The animals were sacrificed at 0, 1, 2, 3, and 4 h after the treatment. The gastric lesions (ulcers) were counted and their severities were calculated, and the volume of gastric secretion and the H+ output were measured. The extent of lipid peroxidation was assessed by measuring the malondialdehyde (MDA) in the gastric mucosa, simultaneously with measurement of the activity of superoxide dismutase (SOD). It was found in these pylorus-ligated rats that: the number of visible gastric lesions was significantly higher 1 h after aspirin administration than at other times; the severity of gastric lesions increased significantly at the 3rd and 4th hour after administration of aspirin; the volume of gastric secretory responses increased gradually after administration of aspirin and to a higher extent than the H+ output; the H+ output was significantly less after aspirin administration than that after pylorus ligation only; the gastric mucosal SOD activity significantly increased 1 h after administration of aspirin, decreasing significantly and gradually thereafter; the tissue level of MDA remained unchanged 1 h after aspirin administration, decreasing significantly thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)