Drug Efflux Transporters
Drug Efflux Transporters - Related Videos
07:47
A Proteoliposome-Based Efflux Assay to Determine Single-molecule Properties of Cl- Channels and Transporters
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Cited by 5 •
2015
Proteoliposomes are used to study purified channels and transporters reconstituted in a well-defined biochemical environment. An experimental procedure to measure efflux mediated by these proteins is illustrated. The steps to prepare proteoliposomes, perform the recordings, and analyze data to quantitatively determine the functional properties of the reconstituted protein are described.
13:17
The Mesenteric Lymph Duct Cannulated Rat Model: Application to the Assessment of Intestinal Lymphatic Drug Transport
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Cited by 48 •
2015
Here we describe a technique to cannulate the mesenteric lymph duct in rats which enables quantification of lipid and drug transport via the lymphatic system following intestinal delivery. The technique can be adapted to assess mesenteric lymph concentrations and/or transport of fluid, immune cells, peptides, proteins and lipophilic molecules.
18:57
Models and Methods to Evaluate Transport of Drug Delivery Systems Across Cellular Barriers
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Cited by 58 •
2013
Many therapeutic applications require safe and efficient transport of drug carriers and their cargoes across cellular barriers in the body. This article describes an adaptation of established methods to evaluate the rate and mechanism of transport of drug nanocarriers (NCs) across cellular barriers, such as the gastrointestinal (GI) epithelium.
01:24
Cellular Membranes and Drug Transport
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2024
Drugs must traverse multiple biological barriers, such as multi-layered skin, single-layered intestinal epithelium, and the plasma membrane, to reach their target sites within the body. The plasma membrane, a highly structured composite of phospholipids, carbohydrates, and proteins, is the cell's protective boundary, facilitating selective substance exchange. Phospholipids arrange themselves into a bilayer, with hydrophilic heads oriented outward and hydrophobic tails facing inward.
01:16
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters
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2026
The pharmacogenetics of drug transporters is increasingly recognized as a critical factor influencing interindividual variability in drug absorption, distribution, and elimination. These membrane-bound proteins regulate drugs' movement across cellular barriers by actively pumping them out (efflux) or facilitating their uptake (influx). Among the major transporter families, ATP-binding cassette (ABC) and solute carrier (SLC) transporters play particularly prominent roles. Genetic polymorphisms...
FAQs
Two energy strategies support outward transport. Many members of the ATP-binding cassette family hydrolyze ATP to power substrate export directly. Other transporter systems rely on electrochemical gradients, using differences across the membrane as the driving force. This distinction helps explain why transporter activity can vary with cellular energy conditions and membrane gradients when drug movement is evaluated.
Transporter placement determines which side of a biological barrier receives greater protection from foreign compounds. Activity in intestinal, kidney, or liver membranes can alter how much drug enters the body or is cleared, while activity at the blood-brain barrier can limit passage into the brain. Consequently, the same compound may show different concentrations across tissues.
Overactive export lowers the intracellular concentration of susceptible drugs, reducing the amount that remains inside a cell. When this effect applies to multiple compounds, cells may display multidrug resistance rather than resistance to only one agent. Studying this mechanism is therefore important for interpreting reduced therapeutic responses and for identifying transporter activity as a potential drug-development target.
Their activity can affect several stages of a compound’s biological journey. Export in the intestine may reduce uptake, whereas activity in the kidney or liver can influence clearance. Transport across protective barriers changes tissue distribution, and altered exposure can contribute to toxicity or reduced effectiveness. These combined effects make transporter behavior relevant to the overall pharmacological profile of a drug.
Evaluation should include tissues where transport changes exposure or clearance: the intestine for uptake, the kidney and liver for elimination, and protective barriers such as the blood-brain barrier for restricted distribution. Considering these sites together helps connect cellular export with organism-level pharmacology and prevents conclusions based on a single tissue from being overgeneralized.
During drug development, transporter activity provides context for whether a candidate may reach effective intracellular or tissue concentrations. In therapeutic response studies, elevated efflux can help explain why exposure does not produce the expected effect. Researchers can therefore examine these proteins when interpreting absorption, distribution, clearance, toxicity, multidrug resistance, and variable treatment responses.