OCT1 (OCT1)

Organic Cation Transporter 1 (gene: SLC22A1), a hepatic uptake transporter expressed on the sinusoidal membrane of hepatocytes. Mediates sodium-independent, electrogenic transport of organic cations and zwitterions into the liver. Clinically significant for metformin hepatic uptake (required for glucose-lowering efficacy) and hepatic clearance of other cationic drugs. Highly polymorphic with functional variants affecting drug response.

Exemples

• OCT1 loss-of-function variants reducing metformin efficacy
• Morphine hepatic uptake and glucuronidation
• Sumatriptan hepatic first-pass metabolism via OCT1 uptake