Oxyntic lesions may be provoked in the rat both by the process of acid secretion and also by gastric acidity

Background:Gastric ischaemia appears to be a common pathogenetic factor for stress ulcers. These ulcers occur predominantly in the oxyntic mucosa, sug gesting that the acid secretory process or its stimulation is involved in t he pathogenesis. Methods: We examined separately the role of the acid secretory process and gastric luminal acidity in the pathogenesis of gastric lesions using the is olated vascularly perfused acid-secreting rat stomach. Results: Pentagastrin-stimulated acid secretion induced submucosal bleeding in the oxyntic mucosa whether accompanied by perfusion of the gastric lume n with saline or a phosphate buffer at pH 7.0. On the other hand, acidity, whether endogenous or introduced by luminal perfusion, induced erosions in both the oxyntic and antral mucosa. Conclusion: It is concluded that the acid secretory process itself contribu tes to the particular vulnerability of the oxyntic mucosa to ischaemia. His tamine released upon stimulation of gastric acid secretion or shortage of e nergy due to the requirements for acid secretion may both contribute to thi s vulnerability. Furthermore, these findings suggest that inhibition of gas tric acid secretion should be superior to antacids in preventing stress ulc ers.