ABC of oral bioavailability: transporters as gatekeepers in the gut.

Article Details

Citation

Copy to clipboard

Dietrich CG, Geier A, Oude Elferink RP

ABC of oral bioavailability: transporters as gatekeepers in the gut.

Gut. 2003 Dec;52(12):1788-95. doi: 10.1136/gut.52.12.1788.

PubMed ID

14633964 [ View in PubMed

]

Abstract

MDR1 (ABCB1), MRP2 (ABCC2), and BCRP (ABCG2) are members of the family of ATP binding cassette (ABC) transporters. These are plasma membrane transporters that are expressed in various organs. The role of MDR1 and MRP2 in the hepatobiliary system is well defined; both contribute to bile formation by transport of drugs, toxins, and waste products across the canalicular membrane. As they transport exogenous and endogenous substances, they reduce the body load of potentially harmful compounds. The role of ABCG2, which is also expressed in the canalicular membrane of hepatocytes, has not yet been fully characterised. All three proteins are also expressed in the apical membrane of enterocytes where they probably control oral availability of many substances. This important "gatekeeper" function of ABC transporters has been recognised recently and is currently under further investigation. Expression and activity of these transporters in the gut may differ between individuals, due to genetic polymorphisms or pathological conditions. This will lead to individual differences in bioavailability of different drugs, toxins, and (food derived) carcinogens. Recent information on substrates, transport mechanisms, function, and regulation of expression of MDR1, MRP2, and BCRP in different species is summarised in this review.

DrugBank Data that Cites this Article

Drug Transporters

Drug	Transporter	Kind	Organism	Pharmacological Action	Actions
Octreotide	Canalicular multispecific organic anion transporter 1	Protein	Humans	Unknown	Substrate Inhibitor	Details
Octreotide	P-glycoprotein 1	Protein	Humans	Unknown	Substrate	Details