title: Pharmacokinetics of hepatobiliary imaging agents in rats: concise communication.
abstract: The distribution and elimination kinetics of Tc-99m pyridoxlidene glutamate (Tc-99m PG), of Tc-99m N-(2,6-dimethyl-phenylcarbamoylmethyl) iminodiacetic acid (Tc-99m HIDA), and of I-131 rose bengal in blood were quantitated after i.v. injection in rats. This was performed by use of a unique indwelling catheter that externalizes the systemic circulation, permitting continuous monitoring of blood radioactivity. The blood activity-time curves of Tc-99m PG and Tc-99m HIDA are described by the sum of three exponential functions. Only two exponentials are required in the case of I-131 rose bengal. The rank order for the rates of loss from blood was Tc-99m HIDA less than Tc-99m PG less than I-131 rose bengal. Bile was collected after administration of Tc-99m HIDA and Tc-99m PG. The total excretion of radioactivity over a 70-min period amounted to 95.7% and 42.8% of the dose of Tc-99m HIDA and Tc-99m PG, respectively. A linear compartmental kinetic model was developed to account for the disappearance from blood and the biliary excretion of these radiopharmaceuticals in rats.
mesh_terms: D000818:Animals; D001646:Bile / Q000378:metabolism; D001659:Biliary Tract / Q000000981:diagnostic imaging* / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism; D007700:Kinetics; D008012:Lidocaine / Q000031:analogs & derivatives / Q000378:metabolism; D008297:Male; D011730:Pyridoxal / Q000031:analogs & derivatives / Q000378:metabolism; D011877:Radionuclide Imaging / Q000379:methods*; D051381:Rats; D012395:Rose Bengal / Q000378:metabolism; D013667:Technetium; D013997:Time Factors
chemical_list: D005971:Glutamates; D012395:Rose Bengal; D011730:Pyridoxal; D013667:Technetium; D008012:Lidocaine