Characterization of In-111(3+) complexes of DTPA amide derivatives: Biodistribution and clearance studied by gamma imaging

A large series of structurally related diethylenetriaminepentaacetic acid a mide derivatives with different structures and lipophilic properties were s ynthesized and radiolabeled with In-111(3+). TWO Of the more hydrophobic co mpounds studied ([In-111]L-9 and [In-111]L-10) showed high affinity for hum an serum albumin (HSA). The biodistribution and clearance properties shown by all complexes upon injection in Wistar rats were followed by gamma imagi ng. The blood retention time of the chelates correlates better with their b inding to HSA than with their hydrophilic/lipophilic ratio. Hydrophile and negatively charged complexes undergo renal retention, while the majority of the lipophilic complexes are retained in the blood for a longer period of time and are cleared through the liver. NUCL MED BIOL 21;6:605-610, 2000. ( C) 2000 Elsevier Science Inc. All rights reserved.