Human organic anion transporter 3 (OAT3)

Human organic anion transporter 3 (OAT3) is a membrane-bound protein encoded by the SLC22A8 gene. It is predominantly expressed on the basolateral membrane of renal proximal tubule cells where it facilitates the uptake and subsequent urinary excretion of a wide range of endogenous metabolites and xenobiotics—including many clinically important drugs such as penicillins, methotrexate, nonsteroidal anti-inflammatory drugs (NSAIDs), antivirals, antibiotics, antihistamines, diagnostic agents, toxins and environmental chemicals. Functionally classified within the solute carrier family as a sodium-independent exchanger coupled indirectly to sodium gradients via dicarboxylates like alpha-ketoglutarate, it plays a critical role in both normal physiology—regulating levels of hormones/metabolites—and pharmacology/toxicology through its impact on drug disposition. Genetic variation within SLC22A8 can significantly affect transport activity leading to inter-individual differences in drug response or susceptibility to adverse effects.

Other names

Organic anion transporter 3SLC22A8Solute carrier family 22 member 8hOAT3

Drugs interact with OAT3 primarily as substrates or inhibitors. The transporter mediates the uptake of these drugs into renal proximal tubule cells for subsequent excretion into urine. Inhibition or genetic variation can alter drug clearance and toxicity profiles by affecting renal elimination rates.