title: Characterization of acetate uptake by the colonic epithelial cells of the rat.
abstract: The characteristics of acetate uptake by colonic epithelial cells of the rat were studied. Clear saturation kinetics of acetate uptake were not observed in these experiments at either 0 degrees C or 30 degrees C. A decrease in the pH of the medium markedly increased the acetate uptake. The activation energy for acetate uptake derived from an Arrhenius plot was about 6.1 kcal/mole. Among the inhibitors tested, no effective inhibition of acetate uptake at 0 degrees C was observed. Metabolic inhibitors severely inhibited transport at 30 degrees C. Inhibition of acetate uptake by other short chain fatty acids, which was non-competitive, was observed. The finding that efflux from the cells was stimulated in the presence of compounds such as pyruvate and bicarbonate supported the notion of a close interrelationship between weak electrolyte transports in vivo. Although the H+ gradient across the cell membrane is suggested to be one of the factors determining the uptake rate, it seems difficult to explain all the results in this way.
mesh_terms: D000042:Absorption; D000085:Acetates / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport; D003106:Colon / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004848:Epithelium / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008433:Mathematics; D051381:Rats; D013696:Temperature
chemical_list: D000085:Acetates