Endogenous Vasopressin Damages Duodenal Mucosa during Haemorrhagic Shock in Rats

The role of endogenous vasopressin was studied in the development of mucosal erosions induced by haemorrhagic shock in the duodenum of the rat. Ischaemia-reperfusion provoked duodenal haemorrhagic lesions and elevated circulating and intramucosal vasopressin level. This mucosal injury was significantly attenuated by a vasopressin pressor receptor antagonist. Moreover, in the vasopressin-deficient Brattleboro homozygous rat, mucosal injury induced by haemorrhagic shock was also reduced. By contrast, when the vasopressin agonist, lysin-vasopressin, was administered, significant aggravation of ischaemia-reperfusion-induced duodenal mucosal injury was seen. These findings indicate the aggressive role of endogenous vasopressin, via its pressor receptors, in the generation of duodenal mucosal stress erosions in haemorrhagic shock.