Role of intracerebroventricular vasopressin in the development of stress-induced gastric lesions in rats

We investigated whether arginine vasopressin (AVP) has a central influence on the development of gastric mucosal lesions evoked by restraint-cold stress in rats. AVP and vasopressin V-1 receptor antagonist were injected intracerebroventricularly (icv) and the rats were exposed to restraint-cold stress for five hours. After decapitation the stomachs were examined for gastric mucosal lesions which were evaluated according to an ulcer score. Three different doses of AVP and V-1 receptor antagonist were administered in order to investigate the effects of extogenous and endogenous AVP on stress-induced gastric mucosal lesions. The intensity of gastric mucosal lesions was reduced when exogenous AVP was injected intracerebroventricularly. On the other hand, vasopressin V-1 receptor antagonist, which was administered by the same route, augmented gastric mucosal lesions. Our findings indicate that AVP, injected centrally, plays a role in preventing the formation of gastric mucosal lesions induced by stress via a central V-1 receptor.