title: Alanine influx across serosal border of Testudo graeca intestine.
abstract: The influx of alanine across the serosal membrane of Testudo graeca intestinal cells with preserved epithelial orientation was examined. Our results suggest that: 1. The mechanism of alanine influx across the serosal membrane of turtle intesintal cells is a carrier-mediated process that has the characteristics of facilitated diffusion. 2. Alanine influx mechanism is independent of intra- and extra-cellular changes in Na+ and K+ concentrations, and is not altered by reversal of Na+ and K+ gradients across the serosal membrane. 3. In Na+-free media the mechanism of transport of alanine at the mucosal membrane has the same pattern of competitive inhibition by amino acids as the serosal.
mesh_terms: D000409:Alanine / Q000378:metabolism*; D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism*; D007700:Kinetics; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D014426:Turtles / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D012964:Sodium; D000409:Alanine; D011188:Potassium