Organic anion-transporting proteins OATP transporters

Cellular defense mechanisms against toxins (A multistep mechanism for elimination of toxic metabolites and xenobiotics. It involves various transport, oxidation, and conjugation steps.) are usually divided into several steps as it is visualized on Fig. 3. Organic anion transporting proteins (OATPs) are responsible for the cellular uptake of endogenous compounds and... 

MDR-ABC Transporters. Figure 3 Detoxification cellular mechanisms. X, toxic compound X-OH, oxidized toxic compound GS-X, conjugated toxic compound OATP, organic anion transporting proteins CYPs, cytochromes GSH, glutathion UDPGIcUA, Uridine 5-diphosphoglucuronic acid PAPs, 3-phosphoadenylylsulfate. 

Organic anion transporters can be divided into three major families organic anion transporters (OATs), organic anion transporting polypeptides (OATPs), and multidrug resistance associated proteins (MRPs) [201]. 

In addition to OATP/Oatp family proteins, some of the organic anion transporter (OAT) family proteins may be responsible for hepatic uptake. Although many OAT family proteins are expressed in the kidney [36], human and rat OAT2 is also expressed in the liver [37, 38]. Human OAT2 transports p-amino-... 

There have been several studies that underscore the importance of unbound concentration in cell-based studies of receptor function. In a model study of the effect of plasma protein binding on the renal transport of organic anions using the expression of various organic anion transporters (OATPs) in Xenopus oocytes, the transport of ochratoxin A, methotrexate, and estrone sulfate was found to be strongly inhibited by the addition of human serum albumin to the culture medium [16]. Similarly, the addition of oq-acid glycoprotein was found to reverse the blockade of sodium-ion current by cocaine in a preparation of cardiac myocytes [17]. 

OATP/oatp Organic anion transporting polypeptide (protein / nucleic acid)... 

Figure 2.1 Hepatocyte basolateral bile acid transporters. Protein-bound bile acids returning in portal blood are taken up by the hepatocyte via the sodium taurocholate co-transporting polypeptide (NTCP) and organic-anion-transporting polypeptide (OATP). In cholestasis bile acids may be returned to blood by the multi-drug-resistance-associated protein 3 (MRP3).

The statins, except for fluvastatin, are poorly absorbed from the gastrointestinal tract [19].They are generally hepatoselective. More lipophilic statins diffuse passively into hepatocytes, and more hydrophilic statins are actively taken up by an organic anion transport protein (OATP) [21]. They are more hepatoselective than the lipophilic statins. 

Organic anion transporter protein inhibition (OATP) - transports drugs into hepatocytes... 

OATP SLC21A3 Polyspecific organic anion transport protein... 

The organic anion transporting polypeptides (rodents Oatps human OATPs) represent a family of proteins responsible for the membrane transport of a large number of endogenous and xenobiotic compounds with diverse chemical characteristics. Since the first expression of Oatplal in 1994, organic anion transporting polypeptide family members have been isolated from a variety of tissues in vertebrate animal species [1]. 

Su Y, Zhang X, Sinko PJ. Human organic anion-transporting pol5T>eptide OATP-A (SLC21 A3) acts in concert with P-glycoprotein and multidrug resistance protein 2 in the vectorial transport of Saquinavir in Hep G2 cells. Mol Pharm 2004 l(l) 49-56. 

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