Gastric cytoprotection: a critical appraisal of the concept, methodology, implications, mechanisms and future research prospects.

Gastric cytoprotection is the property of certain substances, particularly prostaglandins, when used in non-antisecretory doses, to protect the gastric mucosa from becoming inflamed and necrotic on being exposed to noxious agents. An association between alterations in endogenous prostaglandins and gastric mucosal damage induced by a number of drugs has also been observed. The process of adaptive cytoprotection in which mild irritants protect the gastric mucosa against the damaging effects of various necrotizing agents has been shown to be prostaglandin mediated. However, the exact mechanisms underlying this cytoprotective activity have still not been elucidated although a number of hypotheses have been proposed. Recently, thromboxanes, leukotrienes and endogenous sulfhydryls have also been suggested to be involved in the pathogenesis of gastric mucosal damage induced by various necrotizing agents. This review attempts to provide an up-to-date appraisal of the concept, methodology, mechanisms and implications of this phenomenon and suggests that prostaglandins and endogenous sulfhydryls may play a significant role in the pathogenesis of gastric ulceration and may serve an important function in maintaining normal gastric mucosal integrity.