Tc-99m-galactosyl-neoglycoalbumin: in vivo characterization of receptor-mediated binding to hepatocytes.

Abstract

The biodistribution and kinetics of receptor-binding hepatic radiopharmaceutical 99mTc-galactosyl-neoglycoalbumin (Tc-NGA), were investigated using mammalian and avian models. The radiopharmaceutical exhibited 4 significant features associated with receptor-mediated binding at the hepatocyte membrane in mammals: high tissue specificity, high molecular specificity, affinity-dependent uptake and dose-dependent uptake. Diminished hepatic uptake by the avian model illustrated low nonspecific binding. The kinetic sensitivity to ligand-receptor affinity and stoichiometry illustrated the principal feature of receptor-binding radio-pharmaceuticals, namely, quantitative assessment of tissue function and based upon the biochemical interaction of a ligand and its specific receptor.