Modulation by anions of p-aminohippurate transport in bovine renal basolateral membrane vesicles

Pflugers Arch. 1993 Nov;425(3-4):241-7. doi: 10.1007/BF00374173.


In the presence of 10 microM 2-oxoglutarate (2-OG) and of an inward Na+ gradient, uphill [3H]p-aminohippurate (PAH) uptake occurs due to cooperation of the PAH/2-OG exchanger and the Na(+)-coupled 2-OG transporter in bovine renal basolateral membrane vesicles. Uphill PAH uptake is observed with Cl-, but not with gluconate as the bulk anion. To determine specificity and nature of this anion effect [3H]PAH uptake was measured in the presence of several anions without and with ionophores to distinguish indirect from direct effects on the PAH transporter. Na(+)-gradient plus 2-OG-stimulated [3H]PAH uptake is fast with Cl-, intermediate with F-, Br-, I-, NO3- and SCN-, and slow in the presence of gluconate, SO4(2-) and HPO4(2-). Stimulation by Cl-(as compared to gluconate) is attenuated but not abolished, by clamping electrical potential and pH differences to zero, suggesting a partial effect through charge compensation and a major effect of anions on the PAH transporter itself. Indeed, [3H]PAH/2-OG and [3H]PAH/PAH exchange rates under voltage- and pH-clamped condition depend on bulk anions although the anion effects are less pronounced than with Na(+)-gradient plus 2-OG-stimulated [3H]PAH uptake. Since an inward Cl- gradient does not drive [3H]PAH above or below equilibrium distribution, Cl- ions are most probably not translocated by the PAH transporter. We propose that anions modulate the PAH transporter by interacting with a site not directly related to anion transport.

MeSH terms

  • Animals
  • Anions / pharmacology*
  • Biomarkers
  • Cattle
  • Electrophysiology
  • Hydrogen-Ion Concentration
  • In Vitro Techniques
  • Ketoglutaric Acids / pharmacology
  • Kidney / metabolism*
  • Membranes / metabolism
  • Proteins / metabolism
  • p-Aminohippuric Acid / metabolism*


  • Anions
  • Biomarkers
  • Ketoglutaric Acids
  • Proteins
  • p-Aminohippuric Acid