title: Comparison of renal extraction efficiencies for radioactive agents in the normal dog.
abstract: The renal extraction efficiencies for various radioactive agents were measured in normal anesthetized dogs during 1 hr after a single intravenous injection. Radioassays were made on serial blood samples drawn simultaneously from the aorta upstream from the renal arteries and from one renal vein. As a reference substance [131I]o-iodohippurate was injected concurrently in all experiments. Blood clearances from serial venous samples and urinary excretion also were measured. Extraction efficiency from whole blood was calculated as (A-V) divided by A, where A = aortic concentration and V = renal venous concentration. This ratio for commercial [131I]o-iodohippurate fell steadily from 88% at 30 sec to 50% at 1 hr. For "purified" [131I]o-iodohippurate the fall was less marked, to 61% at 1 hr. The EE ratios for all other agents were stable after the first minute. The Tc-99m complexes of DTPA, glucoheptonate, and acetylcysteine had ratios averaging 27-29%. The ratios of Tc-99m DMS and Hg-197 chlormerodrin had much lower average values of 8 and 14%, respectively. None of the newer agents approached the extraction efficiency of [131I]o-iodohippurate.
mesh_terms: D000818:Animals; D001011:Aorta; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000378:metabolism; D004285:Dogs; D007465:Iodohippuric Acid / Q000097:blood / Q000378:metabolism* / Q000652:urine; D007668:Kidney / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000378:metabolism; D011877:Radionuclide Imaging; D012016:Reference Values; D012077:Renal Artery; D012082:Renal Veins; D013667:Technetium / Q000378:metabolism*; D013678:Technology, Pharmaceutical; D013997:Time Factors
chemical_list: D007465:Iodohippuric Acid; D013667:Technetium