Coupled transport of p-aminohippurate by rat kidney basolateral membrane vesicles

Am J Physiol. 1988 Oct;255(4 Pt 2):F597-604. doi: 10.1152/ajprenal.1988.255.4.F597.


p-Aminohippuric acid (PAH) transport by basolateral membrane (BLM) vesicles isolated from rat renal cortex was stimulated very little by a Na+ gradient (out greater than in). However, when micromolar concentrations of glutaric acid or alpha-ketoglutaric acid were added in the presence of a out greater than in Na+ gradient, PAH uptake was accelerated greater than 20-fold and an overshoot of greater than fivefold was produced. Other anions, e.g., fumarate, stimulated PAH uptake very modestly under these conditions (approximately 2-fold), and that stimulation was totally prevented by short circuiting, i.e., with K+ (in = out) and valinomycin. Glutarate-stimulated uptake was inhibited by 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS) and probenecid and was slightly stimulated by the imposition of an inside-negative membrane potential. Furthermore, even in the absence of a Na+ gradient, glutarate-loaded vesicles exhibited a marked acceleration of PAH uptake (5-fold) and a modest overshoot (2.5-fold). These results suggest an indirect coupling of BLM PAH uptake to the Na+ gradient by a cyclic accumulation (Na+-dependent) of glutarate followed by its efflux from the vesicle in exchange for PAH. This coupled system was absent in apical membranes. Thus net secretory transport of PAH may entail Na+-dependent, glutarate-driven PAH uptake at the BLM, followed by the exit of PAH into the lumen down its electrochemical gradient, probably in exchange for other anions, e.g., Cl-, HCO3-, or OH-.

MeSH terms

  • Aminohippuric Acids / metabolism*
  • Animals
  • Anions
  • Biological Transport / drug effects
  • Cell Membrane / metabolism
  • Cell Membrane / physiology
  • Glutarates / metabolism
  • Kidney Cortex / metabolism*
  • Kinetics
  • Lithium / pharmacology
  • Male
  • Membrane Potentials
  • Rats
  • Rats, Inbred F344
  • p-Aminohippuric Acid / metabolism*
  • p-Aminohippuric Acid / pharmacology


  • Aminohippuric Acids
  • Anions
  • Glutarates
  • Lithium
  • p-Aminohippuric Acid