BIODISTRIBUTION OF MODEL RH-105-LABELED TETRADENTATE THIAMACROCYCLES IN RATS

Rh-105(III)Cl-2 complexes with a limited series of [14]ane- and [16]an e-thia macrocycles were prepared and their biodistributions in Sprague -Dawley rats studied. These studies demonstrate that modifications in the structure and composition of the Rh-105-thia macrocycle complexes produce significant differences in their uptake and retention in both the liver and kidneys. The results indicate that the cis-Rh(III)Cl-2-[ 14]ane thiamacrocycles exhibit less kidney retention than the correspo nding trans-Rh(III)Cl-2-[16]ane thiamacrocycles. In addition, the pres ence of a side chain containing a carboxylate group will produce decre ased retention of activity in the kidneys. HPLC analysis of urine from these animals indicates no observable in vivo metabolism or dissociat ion of these chelates in the blood stream. Copyright (C) 1997 Elsevier Science Inc.