ABSTRACT
In general, the use of radionuclides to evaluate hepatocyte function has been limited to the labeling of compounds which are removed from the blood by the liver and excreted into bile with or without metabolic transformations. Hepatocyte uptake across the sinusoidal membrane appears to be selective for a variety of classes of compounds including anions such as bilirubin, the dyes sulfobrom-ophthalein, indocyanine green, and rose bengal, bile acids, porphyrins, and free fatty acids, positively charged quarternary amines and neutral steroid sugar conjugates. Another aspect of hepatocyte physiology which is important to the understanding of the kinetics of radiolabeled compounds handled by the liver involves the capacity of the liver to excrete materials into the bile. A new area of interest in the hepatic localization of radiopharmaceuticals involves the binding of modified proteins to hepatic cell membrane receptors. These proteins normally have a terminal sequence consisting of sialic acid in the end position, and then galactose and N-acetylglucosamine, respectively.
