Routes and mechanism of fluid transport by epithelia.
The mechanism of fluid transport by leaky epithelia and the route taken by the transported fluid are in dispute. A consideration of current mathematical models for coupling of solutes and water, as well as the methodologies for the study of fluid transport, shows that local osmosis best accounts for water movement. Although it seems virtually certain that the tight junctions are water permeable, the fraction of absorbed fluid that crosses the tight junction cannot yet be determined with confidence.
Spring
K R
KR
Laboratory of Kidney and Electrolyte Metabolism, National Heart, Lung and Blood Institute, Bethesda, Maryland 20892-1603, USA. Springk@fido.nhlbi.nih.gov
D000818:Animals; D001692:Biological Transport / Q000502:physiology*; D001826:Body Fluids / Q000378:metabolism / Q000502:physiology*; D004848:Epithelium / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D009995:Osmosis; D019108:Tight Junctions / Q000502:physiology