Abstract
Gastric lesions were developed in the communication box paradigm (CB) in mice as well as in the activity-stress paradigm (AS) in rats. Treatment with sulpiride (10-320 mg/kg, p.o.) attenuated these psychological stress-induced gastric lesions in a dose-dependent manner, while it failed to suppress those induced by physical stress such as restraint water-immersion (WI) and indomethacin treatment (IND). In contrast, treatment with famotidine (0.32-10 mg/kg, p.o.) dose-dependently attenuated the gastric lesions induced by physical stress but not those by psychological stress. Pylorus-ligation study revealed that famotidine strongly reduced gastric acid secretion, whereas sulpiride minimally affected that. It was also demonstrated that physical stress (WI) enhanced acid secretion while psychological stress (CB and AS) rather depressed that. These results suggest that the mechanisms of gastric lesion formation are clearly different between physical and psychological stress and that sulpiride specifically attenuates psychological stress lesions possibly through a central mechanism.
