Endogenous vasoactive mediators in defense of portal hypertensive gastric mucosa

Abstract

The inflammatory mediators can alter the integrity of mucosa by effectively influencing the various components of the mucosal defense, which are a combination of factors that allow the mucosa withstand exposure to substances with different types of pH range, temperature, and osmosis, solutions with detergent properties (bile) and bacterial products that can activate local and systemic inflammatory reactions. On the other hand, our previous research showed that different kinds of intragastric pH range can protect or induce gastric damage in portal hypertensive rats. When damage occurs to the mucous membrane, repair of the lesion can be activated quickly, limiting the possibility of harmful substances (bacterial products) coming into contact with the systemic circulation. The resistance of the gastric mucosa to injury depends, ultimately, on a balance between defensive factors and aggressive factors present in the lumen of the mucosa. Various components of mucosal defense can be influenced by inflammatory mediators. Some of these mediators are prostanoids, nitric oxide, endothelins, cytokines, free radicals, neuropeptides and Helicobacter pylori. These mediators contribute to both the modulation of mucosal defense and the pathogenesis of gastric mucosal injury, and will be described a little more detail in the present paper.