Solute carrier family 22 member 3 (OCT3)

Solute carrier family 22 member 3 (OCT3) is a plasma membrane polyspecific transporter belonging to the SLC22 family and the major facilitator superfamily (MFS)[1][5]. It mediates the electrogenic, sodium-independent transport of diverse endogenous (e.g., monoamines like dopamine and serotonin) and exogenous organic cations (drugs, toxins)[4][5]. OCT3 displays a broad tissue distribution, including heart, liver, kidney, placenta, brain, and other tissues[4][5][9]. Its function is critical for the low-affinity, high-capacity clearance of monoamines outside of neurons and for the disposition of therapeutic drugs and xenobiotics. OCT3 is targeted and inhibited by structurally diverse drugs and is modulated by stress hormones such as corticosterone[1][5]. Genetic variants and altered expression can influence susceptibility to metabolic, neuropsychiatric, and cardiovascular diseases, and underlie variability in drug response and toxicity[4][10]. Its wide substrate profile also means OCT3 plays a key role in drug-drug interactions in clinical pharmacology.

Other names

Organic cation transporter 3Extraneuronal monoamine transporter (EMT)SLC22A3

Inhibition or modulation of OCT3 alters the uptake and clearance of endogenous and exogenous organic cations, impacting levels of neurotransmitters, drug kinetics, and response to therapy[1][4][5][10].