Influence of the bifunctional chelate on the biological behavior of Tc-99m-labeled chemotactic peptide conjugates

Conjugates of For-MLFK and For-NleL-FNleYK with S-benzyl mercaptoacetyl dip eptides containing, respectively, zero, one, and two carboxyl functions in their structures were prepared and labeled with Tc-99m. In vitro binding st udies using isolated human granulocytes indicated specific receptor binding of the radiolabeled conjugates, The fraction of granulocyte associated act ivity was determined after incubation with total blood, Biodistribution stu dies of the Tc-99m-peptides in normal mice revealed a very fast blood clear ance proceeding mainly via the hepatobiliary system, Urinary excretion was higher for conjugates containing carboxyl functions in their ligand structu res. NUCL MED BIOL 27;8:769-779, 2000. (C) 2000 Elsevier Science Inc. All r ights reserved.