The Role of Extracellular Matrix in Transperitoneal Transport of Water and Solutes

Abstract

♦ Objective To define the extracellular matrix (ECM), to discuss the physical properties of its components and their impact on transport, and to review data in humans and in animals on the importance of hyaluronan to peritoneal dialysis. ♦ Methods Literature survey. ♦ Results The ECM fills the interstitium between parenchymal cells and blood vessels in the subperitoneal interstitium. It is responsible for the interstitial resistance to solute and water transfer through the peritoneal barrier. Major components are collagen and hyaluronan, which are synthesized locally in the peritoneal tissue. Synthesis and deposition of these components increase with inflammation, and concentrations of the components influence the mechanical properties of the tissue and the interstitial Starling forces as well as transport. Removal of hyaluronan appears to increase the rates of water and large-solute transport. Addition of hyaluronan to dialysate appears to enhance fluid recovery and to reduce protein loss. ♦ Conclusion Many of the physicochemical properties of ECM components are well described, but a large knowledge gap remains concerning the in vivo consequences of specific alterations in the interstitial components. More research is needed.