Carbenoxolone disodium salt, Panx1 hemichannel inhibitor

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

OATP1B1 also known as SLCO1B1 and OATP1B3 also known as SLCO1B3 are members of the organic anion transporting polypeptide family. These proteins serve as key transporters involved in the uptake of a wide range of endogenous and exogenous compounds including drugs into hepatocytes. OATP1B1 has a molecular mass of approximately 85 kDa and is predominantly expressed in the human liver. OATP1B3 shares similar characteristics but possesses distinct substrate specificity and expression patterns being localized similarly in the liver but also found in other tissues such as the pancreas. These transporters facilitate the movement of substances across cellular membranes influencing drug disposition and metabolism.

Biological function summary

OATP1B1 and OATP1B3 participate in the sodium-independent transport of bile acids bilirubin and various drugs. They do not typically form part of larger protein complexes but interact closely with other hepatic transporters to regulate the enterohepatic circulation of bile acids and bilirubin. Through their activity these transporters significantly affect the pharmacokinetics of many therapeutic agents impacting both therapeutic efficacy and the potential for drug-drug interactions. Their function ensures the proper uptake and processing of substrates within the liver contributing to the body's metabolic balance.

Pathways

OATP1B1 and OATP1B3 are integral components of the hepatic drug uptake pathway directly influencing the hepatic clearance of drugs. They play significant roles in the bile acid recycling pathway which maintains bile acid homeostasis. Both transporters interact with cytochrome P450 enzymes such as CYP3A4 to facilitate the metabolic processing of drugs within hepatocytes. Their coordinated action with these enzymes assists in the elimination of bile acids and other anions thereby supporting normal liver function and detoxification processes.

Alterations in OATP1B1 and OATP1B3 function associate with drug-induced liver injury and hyperbilirubinemia. Genetic polymorphisms in SLCO1B1 and SLCO1B3 can lead to altered transporter activity impacting drug disposition and increasing the risk of adverse drug reactions. A notable example is the association between SLCO1B1 variants and increased systemic exposure to statins which can result in statin-induced myopathy. Additionally conditions such as Rotor syndrome link to mutations in SLCO1B1 and SLCO1B3 leading to conjugated hyperbilirubinemia due to impaired hepatic uptake of bilirubin. These relationships highlight the clinical importance of OATP1B1 and OATP1B3 in pharmacogenomics and disease risk assessment.