Biomaterial Database

Evaluation of peritoneal membrane pore models. 1992

J K Leypoldt

Research Service, VA Medical Center, Salt Lake City, UT 84148.

Pore models of peritoneal fluid and solute transport are reviewed and critiqued. Although several pore models of the peritoneal membrane have been previously formulated, a model containing three distinct pore sizes is required to accurately simulate both the molecular size dependence of solute transport and the time dependence of fluid transport during peritoneal dialysis in man. Nevertheless, certain observations from peritoneal dialysis experiments using animals do not agree with predictions from the three-pore model. These discrepancies suggest that the three-pore model of peritoneal transport based exclusively on capillary physiology is incomplete. Moreover, our inability to accurately estimate peritoneal reflection coefficients for small osmotic solutes questions whether lymph flow rates from the peritoneal cavity calculated using the three-pore model are reliable. Further experimental and theoretical studies are needed to obtain a better understanding of peritoneal transport physiology.

UI	MeSH Term	Description	Entries
D008196	Lymph	The interstitial fluid that is in the LYMPHATIC SYSTEM.	Lymphs
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D010530	Peritoneal Dialysis	Dialysis fluid being introduced into and removed from the peritoneal cavity as either a continuous or an intermittent procedure.	Dialyses, Peritoneal,Dialysis, Peritoneal,Peritoneal Dialyses
D010537	Peritoneum	A membrane of squamous EPITHELIAL CELLS, the mesothelial cells, covered by apical MICROVILLI that allow rapid absorption of fluid and particles in the PERITONEAL CAVITY. The peritoneum is divided into parietal and visceral components. The parietal peritoneum covers the inside of the ABDOMINAL WALL. The visceral peritoneum covers the intraperitoneal organs. The double-layered peritoneum forms the MESENTERY that suspends these organs from the abdominal wall.	Parietal Peritoneum,Peritoneum, Parietal,Peritoneum, Visceral,Visceral Peritoneum,Parametrium,Parametriums
D002199	Capillary Permeability	The property of blood capillary ENDOTHELIUM that allows for the selective exchange of substances between the blood and surrounding tissues and through membranous barriers such as the BLOOD-AIR BARRIER; BLOOD-AQUEOUS BARRIER; BLOOD-BRAIN BARRIER; BLOOD-NERVE BARRIER; BLOOD-RETINAL BARRIER; and BLOOD-TESTIS BARRIER. Small lipid-soluble molecules such as carbon dioxide and oxygen move freely by diffusion. Water and water-soluble molecules cannot pass through the endothelial walls and are dependent on microscopic pores. These pores show narrow areas (TIGHT JUNCTIONS) which may limit large molecule movement.	Microvascular Permeability,Permeability, Capillary,Permeability, Microvascular,Vascular Permeability,Capillary Permeabilities,Microvascular Permeabilities,Permeabilities, Capillary,Permeabilities, Microvascular,Permeabilities, Vascular,Permeability, Vascular,Vascular Permeabilities
D004058	Diffusion	The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.	Diffusions
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic
D016062	Porosity	Condition of having pores or open spaces. This often refers to bones, bone implants, or bone cements, but can refer to the porous state of any solid substance.	Porosities