Energetics of renal Na+ and H+/L-alanine co-transport systems.
The stoichiometric properties of Na+- and H+-dependent L-alanine transporters recently identified in luminal-membrane vesicles prepared from proximal convoluted tubules (pars convoluta) and proximal straight tubules (pars recta) of rabbit kidney were studied. We provide indirect evidence suggesting that one Na+ and one H+ ion are co-transported with the L-alanine molecule via Na+-dependent and H+-dependent transport systems located in vesicles from pars convoluta. Furthermore, our experimental data suggest that both the high-affinity and the low-affinity Na+-dependent L-alanine transport systems of pars recta vesicles operate with a 1:1 stoichiometry.
Jessen
H
H
Institute of Medical Biochemistry, University of Aarhus, Denmark.
Vorum
H
H
Jørgensen
K E
KE
Sheikh
M I
MI
D000409:Alanine / Q000493:pharmacokinetics*; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004734:Energy Metabolism / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D007672:Kidney Cortex / Q000378:metabolism; D007679:Kidney Medulla / Q000378:metabolism; D011522:Protons; D011817:Rabbits; D012964:Sodium / Q000494:pharmacology*
D011522:Protons; D012964:Sodium; D005947:Glucose; D000409:Alanine