Repeated recurrence of gastric mucosal lesions in rats after a single treatment with compound 48/80, a mast cell degranulator.

We examined the recurrence of gastric mucosal lesions in rats after a single treatment with compound 48/80 (C48/80), a mast cell degranulator. During the period of 0.5 h to 24 h after treatment with C 48/80 (0.75 mg/kg, i.p.), an apparent recurrence of gastric mucosal lesions was found 18 and 24 h after the lesion formation, progression, and recovery occurred during the period of 12 h. Gastric mucosal blood flow showed the maximum reduction at 0.5, 16, and 22 h after treatment followed by the maximum recovery of the decrease at 12, 20, and 24 h, respectively. Gastric mucosal myeloperoxide and xanthine oxidase activities and lipid peroxide content showed the maximum increase at 3, 18, and 24 h after treatment. Gastric mucosal superoxide dismutase activity unchanged after treatment and gastric mucosal catalase activity decreased only at 24 h. Gastric mucosal Se-glutathione peroxidase activity and vitamin E, ascorbic acid, and hexosamine contents showed their maximum decrease at 3, 18, and 24 h after treatment. Gastric mucosal non-protein SH content showed the maximum decrease at 0.5, 16, and 22 h after treatment. Serum histamine and serotonin concentrations increased rapidly after treatment but the increases in serum histamine and serotonin concentrations diminished completely until 12 and 14 h, respectively. These results indicate that lesions recur repeatedly accompanied with an ischemia-reperfusion-like change in blood flow, inflammation, and disruption of antioxidant defense systems in the gastric mucosa of rats in no relation to released histamine and serotonin after a single C48/80 treatment.