Organic anion transport polypeptides (OATPs) are a group of integral membrane proteins that are involved in the transportation of organic anions across cell membranes. These transporters are predominantly found in liver tissue, but they are also present in other organs such as the kidneys, intestines, and brain.
OATPs play a crucial role in the absorption, distribution, and elimination of numerous endogenous substances and xenobiotics. These substances include bile acids, hormone conjugates, drugs, toxins, and various metabolites. OATPs are capable of mediating both uptake and efflux of organic anions, depending on physiological and pathophysiological conditions.
The transport process facilitated by OATPs is energy-dependent and involves the movement of substrates from the extracellular space into the cell, or vice versa, through a process known as facilitated diffusion. OATPs exhibit broad substrate specificity, allowing them to transport a wide range of compounds.
Impairment or dysfunction of OATPs can lead to altered drug uptake and disposition, resulting in variations in drug response and efficacy. OATP polymorphisms have been associated with interindividual variability in drug pharmacokinetics, therapeutic outcomes, and potential drug-drug interactions.
In summary, organic anion transport polypeptides are a group of membrane transporters that play a crucial role in the transportation of organic anions, including drugs and other substances, across cell membranes. Their broad substrate specificity and involvement in drug metabolism and elimination make them important targets for understanding drug transport and developing efficient therapeutic strategies.
