3 - Immune Regulation of Intestinal Arachidonic Acid Metabolism: Effects on Intestinal Water and Electrolyte Transport

Abstract

This chapter discusses the immune regulation of intestinal arachidonic acid (AA) metabolism. AA metabolites appear to play essential roles both in health and disease. Perhaps, the most prominent of these effects is the alteration in epithelial electrolyte transport and passive permeability stimulated by AA metabolism, mediated both by direct stimulation of the enterocyte and by release of additional mediators from underlying cells of the lamina propria, such as enteric neurons and subepithelial fibroblasts. AA metabolites also have effects on blood flow and capillary permeability, alter motility, and, in the case of prostaglandins, have cytoprotective properties. AA metabolites are important in the initiation and amplification of the immune response and appear to have a pivotal role in diseases such as Crohn's disease and ulcerative colitis. They may also have a role in modifying or promoting wound healing and mucosal regeneration. The chapter discusses the immune and inflammatory regulation of AA metabolism relative to alterations in intestinal electrolyte transport.