Role of Eicosanoids and Related Mediators in Gastric Mucosal Ulceration

Abstract

Although prostaglandins are protective in the gastric mucosa, not all eicosanoids exert such actions. Thus, the cyclo-oxygenase product, thromboxane A₂, generated locally from platelets or its stable mimetic (U-46619) can augment damage induced by topical irritants in the canine gastric mucosa. In the rat, we have shown that local application of U-46619 to the gastric sub-mucosa exerts profound vaso-constrictor actions on the arterioles and venules, the vessels that regulate mucosal blood flow, such actions predicting a pro-ulcerogenic potential. To investigate the direct intravascular actions of such pro-ulcerogenic mediators, we have recently developed a technique that allows close-arterial administration to the rat stomach in vivo (1).