PMCOl 306 Transporters

OAT1

Uptake pump, Found in the basolateral side of the kidney where it takes up small and hydrophilic organic anions such as decarboxylates and cyclic nucleotides

OAT3

Uptake pump, Found in the basolateral side of the kidney where it takes up small and hydrophilic organic anions such as decarboxylates and cyclic nucleotides

OATP family

Uptake pump, uptakes drugs from the apical side in the intestines and the basolateral side in the hepatocytes. Transports large hydrophobic organic anions such as bile acids, thyroid hormones, prostaglandins and steroid hormone conjugates

OCT1

Uptake pump that is highly expressed in the liver basolateral side where it enhances uptake of hepatic basic drugs. transports Metformin, cisplatin, procainamide and cimetidine. Especially metformin

OCT2

Uptake pump highly expressed in the basolateral side of the kidney. Enhances uptake of substrates into renal tubular membrane. transports Metformin, cisplatin, procainamide and cimetidine

OCT3

Uptake pump found in liver, kidney, and intestinal epithelial. transports Metformin, cisplatin, procainamide and cimetidine

Permeability Glycoprotein (P-gp)

Efflux pump that is not specific with respect to substrates. Exports neutral or positively charged hydrophobic molecules in intestine, BBB, placenta, kidney, and liver. Highly expressed in tumour cells. Responsible for 85% for paclitaxel excretion

MRP2

Efflux pump found in apical membrane of kidney, Liver, and intestine. Involved in biliary excretion of bilirubin and glutathione. Inhibition of this drug can lead to severe cholestasis and hyperbilirubinemia

BCRP

Efflux pump found in intestinal membrane, liver, brain, and placenta. Limits drug accumulation (like irinotecan and rosuvastatin). Regulates BBB and maternal-fetal barrier. Controls oral bioavailability

BSEP

Efflux pump in Duct membrane of hepatocytes that transports bile salts and bile acids from hepatocytes to bile tubules. Inhibition causes toxic accumulation of bile salts in cells. Not considered a significant transporter involved in biliary clearance of drugs

MATE

Effluc pump that is a SLC transporter with broad substrate specificity. Exchanges organic cations through electroneutral exchange with protons are found in prokaryotes and eukaryotes. Complements OCT1/2. Found on basolateral side of hepatocytes and proximal tubular cells.

PEPT1

Apical enterocyte transporter responsible for taking up amino acids and the smallest peptides.