Effect of the Tc-Nitrido group on the behaviour of 99mTc-radiopharmaceuticals

Abstract

The preparation of the ^99mTcN-complexes of gluconate, EHDP, HIDA and PIPIDA by substitution reactions of ^99mTcNCl₄⁻ is described. Studies of the distribution of these complexes in mice indicate that the presence of the Tc-nitrido group significantly alters the biological properties of the ^99mTc-complexes formed using these ligands. Results suggest that the ^99mTcN-complexes of these ligands are labile and undergo some ligand exchange in vivo.