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

The biodistribution and kinetics of a receptor-binding hepatic radiopharmaceutical, Tc-99m-galactosyl-neoglycoalbumin (Tc-NGA), were investigated using mammalian and avian models. The radiopharmaceutical exhibited four significant features associated with receptor-mediated binding at the hepatocyte membrane in mammals: (a) high tissue specificity, (b) high molecular specificity, (c) affinity-dependent uptake, and (d) dose-dependent uptake. Diminished hepatic uptake by the avian model illustrated low nonspecific binding.

Clinical experience with 99mTc-disofenin as a cholescintigraphic agent.

99mTc-disofenin, a derivative of iminodiacetic acid, was used for cholescintigraphy in 6 volunteers (in addition to assessment of blood and urine clearance) and in 82 patients referred for evaluation of hepatobiliary tract disease. This radionuclide was cleared rapidly from the blood by the hepatocytes, which permitted satisfactory to excellent images of the hepatobiliary system; interference by renal activity was seen in only 9/82 patients (11%). Acute cholecystitis was correctly diagnosed in 20 patients, although 9 (45%) had jaundice; bilirubin levels ranged from 1.