Mechanisms of renal anionic drug transport.

By utilizing filtration, active secretion and reabsorption processes, the kidney can conserve essential nutrients, and eliminate drugs and potentially toxic compounds. Active uptake of organic anions and cations across the basolateral membrane, and their extrusion into the urine across the brush border membrane mainly takes place in the renal proximal tubule cells, and is facilitated via a range of substrate-specific tubular transporters. Many drugs and their phase II conjugates are anionic compounds, and therefore renal organic anion transporters are important determinants of their distribution and elimination. Competition for renal excretory transporters may cause drugs to accumulate in the body leading to toxicity, which is a potential hazard of concomitant drug administration. Here, we present a brief update on the most prominent human proximal tubule organic anion transporters, which either belong to the ATP-binding cassette (ABC) or the solute carrier transporter (SLC) families. We focus on the participation of the individual transporters in renal anionic drug elimination, in an attempt to understand their overall biological and pharmacological significance, hoping to inspire further studies in the renal transporters field.