Validity of kissing gastric ulcers induced in rats for screening of antiulcer drugs.

We examined the validity of kissing gastric ulcers induced in rats by determining the effects of conventional antiulcer drugs. Gastric ulcers were produced by luminal application of 60% acetic acid (0.2 mL, 45 s) to an area clamped with a pair of forceps. The ulcers were evaluated as to either the ulcerated area (mm2) or ulcer index (ulcerated area x depth). The healing of kissing ulcers was significantly enhanced by 2 week treatment with oral omeprazole (10, 30 mg/kg per day), leminoprazole (30, 60 mg/kg per day) or cimetidine (300, 450 mg/kg per day). The rate of healing was > 50% to both the ulcerated area and ulcer index. Aluminium hydroxide (up to 1800 mg/kg per day) had no effect on ulcer healing on the ulcerated area, but it caused a significant reduction in the ulcer index. Gastric acid secretion was significantly inhibited by repeated administration of omeprazole, leminoprazole and cimetidine in a dose-dependent manner. Aluminium hydroxide significantly increased the pH of the gastric contents. The mechanism of action of these drugs appears to involve partly the inhibition of gastric acid secretion and neutralization of secreted acid. We conclude that kissing gastric ulcers are a sensitive ulcer model for the screening of antiulcer drugs.