Table 1.
Characteristics of the human organic cation transporters of the SLC22A family.
| Major Clade | Subclade | Gene | Protein | Tissue Distribution | Endogenous Substrates | Xenobiotic Substrates/Inhibitors |
|---|---|---|---|---|---|---|
| OCT | Oct | SLC22A1 | OCT1 | Liver and to a less extent also in brain, heart, immune cells, intestine, kidney and lung | Biogenic monoamines, biogenic polyamines, catecholamines, ethanolamines, neuromodulators, vitamins, prostaglandins | Cimetidine, ciprofloxacin, famotidine, lamivudine, lamotrigine, metformin, O-desmethyltramadol, ondansetron, quinidine, ranitidine, sumatriptan, tropisetron, zalcitabine |
| OCT | Oct | SLC22A2 | OCT2 | Kidney, brain, lung | Acetylcholine, dopamine, serotonin | Amantadine, anti-malarials, atenolol, cimetidine, entecavir, fluoroquinolones, metformin, procainamide, quinidine, sulpiride |
| OCT | Oct | SLC22A3 | OCT3 | Widely expressed | Norepinephrine | Metformin, wogonin |
| OCT | Octn | SLC22A4 | OCTN1 | Kidney, bone marrow, trachea, fetal liver (at lower levels in many tissues) | Acetylcholine, carnitine | Ergothioneine, entecavir, fluoroquinolones, gabapentin, sulpiride |
| OCT | Octn | SLC22A5 | OCTN2 | Intestine, kidney, placenta, mammary gland | Carnitine | Entecavir, fluoroquinolones, sulpiride |