A new screening method for anti-ulcer agents: psychological stress produced by intraspecies emotional communication

Psychological stress produced by intraspecies emotional communication in a communication box was studied to see whether it could be applied to a new screening method for anti-ulcer agents. There were two groups of mice, the 'sender' mice that received electrical foot shocks and showed emotional responses such as piloerection, abnormal squealing and jumping, and the 'responder' mice that were affected by the sender's emotional responses without foot shock. The gastric lesions (erosions) produced by conditioned emotional stimuli were observed in both groups. The effects of the anti-ulcer drugs cetraxate, cimetidine and gefarnate were examined. In 'senders', the gastric lesions were significantly suppressed by the administration of cetraxate at a dose of 200 mg/kg (p.o.) or cimetidine at doses of 30 and 100 mg/kg (p.o.). The gastric lesions in 'responders' were significantly suppressed by two administrations of cetraxate at doses of 100 and 200 mg/kg (p.o.), cimetidine at doses of 10-100 mg/kg (p.o.) or gefarnate at a dose of 200 mg/kg (p.o.). The gastric lesions of 'responders' were more sensitive to anti-ulcer drugs. The present results indicate that the gastric erosions of 'responders' are useful for the evaluation of anti-ulcer agents.