Gadoxetate disodium

Gadoxetate sodium (CAS No.: 135326-22-6) is a synthetic small molecule gadolinium based paramagnetic research probe in the hepatobiliary magnetic resonance imaging contrast agent class, widely used in preclinical imaging science to study hepatic transport biology, lesion conspicuity, and tissue distribution kinetics in biomedical research and drug discovery workflows. Functionally, its signal enhancing behavior is linked to T1 relaxation shortening after distribution in extracellular space followed by selective uptake in viable hepatocyte populations and subsequent biliary handling, making it a practical tool for investigating hepatocellular function and liver microenvironment heterogeneity in experimental systems. Mechanistically, published research usage is commonly interpreted through transporter mediated processes associated with hepatic uptake and excretory flux, including organic anion transporting polypeptide dependent influx and canalicular export pathways, rather than receptor agonism or enzyme inhibition paradigms typical of pharmacology screening compounds. In this context, it is best categorized as an imaging functional probe for hepatobiliary physiology and pathology modeling, including focal liver lesion characterization and longitudinal assessment of liver injury related phenotypes in animal studies, with additional reports noting gadolinium retention patterns in fibrosis associated models without clear acute histopathologic injury under studied conditions. Specific potency style metrics such as IC50 or EC50 are generally not the primary performance descriptors for this agent, and when quantitative in vitro benchmarking is required, studies typically emphasize concentration dependent relaxometric effects and transporter associated uptake behavior over classical bioactivity endpoints, with experimental exposures often spanning method dependent ranges selected for assay sensitivity and matrix conditions. Typical applications include hepatocyte and liver derived cell systems for uptake and disposition studies, rodent imaging paradigms for liver function stratification and lesion detection research, and translational imaging biomarker development in compound evaluation programs, where the concentrations or doses used in experiments typically depend on specific experimental designs and research objectives.