Paramagnetic complexes of manganese(II), iron(III), and gadolinium(III) as contrast agents for magnetic resonance imaging. The influence of stability constants on the biodistribution of radioactive aminopolycarboxylate complexes

Journal Article · Wed Apr 01 04:00:00 EST 1987 · Invest. Radiol.; (United States)

DOI:https://doi.org/10.1097/00004424-198704000-00008· OSTI ID:6278953

Fornasiero, D; Bellen, J C; Baker, R J; Chatterton, B E

Paramagnetic complexes of manganese(II), iron(III), and gadolinium(III) with many ligands appear to undergo ligand substitution in vivo, producing biodistribution data similar to the hydrated metal ions. To identify ligands likely to be valuable in the preparation of paramagnetic contrast agents, a series of aminopolycarboxylate complexes with stability constants increasing in the order iminodiacetic acid (IDA) less than nitrilotriacetic acid (NTA) less than EDTA less than CDTA less than or equal to DTPA was prepared with /sup 54/Mn(II), /sup 59/Fe(III), and /sup 153/Gd(III) at both tracer and carrier levels. Biodistribution studies in mice suggested that complexes remained unchanged in vivo if their stability constants (K1) were approximately greater than 10(16) for Mn(II) and Gd(III) and greater than 10(22) for Fe(III) complexes at tracer levels. Metal complexes with added carrier appeared to be effectively more stable in vivo, possibly due to dissociation and saturation of metal-binding sites. To avoid the accumulation of metal ions in tissues, new paramagnetic contrast agents containing these metal ions will require stability constants equal to or greater than those identified here.

• Research Organization: Royal Adelaide Hospital, South Australia
• OSTI ID: 6278953
• Journal Information: Invest. Radiol.; (United States), Journal Name: Invest. Radiol.; (United States) Vol. 4; ISSN INVRA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
AMINO ACIDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOXYLIC ACIDS
CHELATING AGENTS
COMPLEXES
CONTRAST MEDIA
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
DISTRIBUTION
DRUGS
DTPA
EDTA
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
EVEN-ODD NUCLEI
GADOLINIUM
GADOLINIUM 153
GADOLINIUM ISOTOPES
INTERMEDIATE MASS NUCLEI
IRON
IRON 59
IRON ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LIGANDS
MAGNETIC RESONANCE
MAMMALS
MANGANESE
MANGANESE 54
MANGANESE ISOTOPES
METALS
NMR IMAGING
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
RADIOISOTOPES
RADIOPROTECTIVE SUBSTANCES
RARE EARTH ISOTOPES
RARE EARTH NUCLEI
RARE EARTHS
RATS
RESONANCE
RODENTS
TISSUE DISTRIBUTION
TRACER TECHNIQUES
TRANSITION ELEMENTS
VERTEBRATES