Abstract
1. Relationship between urease activity in gastric mucosa and ammonia content of gastric juice was examined in 3 species of laboratory animals. The close relation was confirmed between them. 2. Urease inhibitory effects of some agents were compared in vivo and their influence on gastric ammonia production was examined in mice. Benzohydroxamic acid, a specific inhibitor of urease, distinctively reduced gastric ammonia production. 3. By intravenous injection of urea, ammonia content of gastric juice was markedly increased. 4. Repeated administrations of urea activated gastric urease activity and gastric ammonia production. 5. Repeated administrations of urea reduced the incidence of gastric errosion which was induced by reserpine in mice. 6. All these results may suggest the important role of gastric urease in defensive mechanism of gastric mucosa.
