Amino acid-dependent sodium transport in plasma membrane vesicles from rat liver.
The L-alanine-dependent transport of sodium ions across the plasma membrane of rat-liver parenchymal cells was studied using isolated plasma membrane vesicles. Sodium uptake is stimulated specifically by the L-isomer of alanine and other amino acids, whose transport is sodium-dependent in rat-liver plasma membrane vesicles. The L-alanine-dependent sodium flux across the membrane is inhibited by an excess of Li+ ions, but not by K+ or choline ions. Sodium transport is sensitive to -SH reagents and ionophores, and is an electrogenic process: a membrane potential (negative inside) can enhance L-alanine-dependent sodium accumulation. The data presented provide further evidence for a sodium-alanine cotransport mechanism.
D000409:Alanine / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002474:Cell-Free System; D004734:Energy Metabolism / Q000187:drug effects; D007476:Ionophores / Q000494:pharmacology; D008099:Liver / Q000378:metabolism*; D008297:Male; D051381:Rats; D012964:Sodium / Q000378:metabolism*
D000596:Amino Acids; D007476:Ionophores; D012964:Sodium; D000409:Alanine