Water and electrolyte absorption and secretion in the small intestine

This paper provides a brief overview of recent studies dealing with small intestinal electrolyte and water transport. The topics reviewed include 1) the regulation of small intestinal HCO₃^- secretion; 2) the roles of the Na⁺-HCO₃^-, Cl^--HCO₃^-, and Na⁺-H⁺ transporters in intracellular pH homeostasis; 3) the ontogeny of the Na⁺-H⁺ antiporter; 4) the effect of inflammatory mediators released by subepithelial mesenchymal cells on intestinal electrolyte secretion; 5) altered electrolyte and mineral transport in various pathophysiologic models, such as the spontaneously hypertensive rat and the nippostrogylosis model of malabsorption; 6) the mechanisms of mineral transport and the influence of diet and membrane composition on mineral transport; and 7) the role of intestinal transferrin receptors in iron absorption.