Na+-electrochemical potential-mediated transport of D-glucose in renal brush border membrane vesicles.
The uphill transport of D-glucose in renal brush border membrane vesicles was correlated with the Na+ electrochemical gradient. Each component of the electrochemical potential, the membrane potential or the Na+ chemical gradient, when assayed independently supported the concentrative uptake of the sugar. When the two components were combined the rates of D-glucose uptake were additive. Accumulation of D-glucose as a function of various Na+ gradients, in the absence of a membrane potential, suggests a 1:1 stoichiometry between sugar and Na+ uptake. These findings are consistent with the role of ionic gradients in energizing uphill solute transport and, thus, provide experimental evidence that extends the chemiosmotic theory to the Na+ electrochemical potential-mediated transport of D-glucose in mammalian tissues.
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism* / Q000648:ultrastructure; D007700:Kinetics; D008564:Membrane Potentials; D008871:Microvilli / Q000187:drug effects / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism / Q000494:pharmacology*; D014634:Valinomycin / Q000494:pharmacology
D014634:Valinomycin; D012964:Sodium; D005947:Glucose; D011188:Potassium