Unstirred Water Layers in Intestine: Rate Determinant of Fatty Acid Absorption from Micellar Solutions

• Published in: Science (American Association for the Advancement of Science) Vol. 174; no. 4013; pp. 1031 - 1033
• Main Authors: Wilson, Frederick A., Sallee, Verney L., Dietschy, John M.
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 03-12-1971
• Subjects: Animals; Bile acids; Bile Acids and Salts - metabolism; Biological Transport; Cell Membrane Permeability; Cell membranes; Fatty acids; Fatty Acids - metabolism; Intestinal Absorption; Kinetics; Leaves; Lipids; Micelles; Models, Biological; Molecules; Monomers; Rats; Relative humidity; Solutes
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.174.4013.1031

Bile acid and fatty acid uptake from micellar solutions by intestinal cells fails to reflect the incremental free energy changes expected for permeation that is rate limited by cell membranes. However, altering the size of the diffusing particle or the thickness of the unstirred water layer does change uptake. These observations show that the unstirred water layer is rate limiting for intestinal absorption of lipids from micellar solutions.