Metabolic fate in the dog of the nitroxide moiety in a compound with potential utility as a contrast agent in MRI
Nitroxides, paramagnetic compounds with demonstrated effectiveness as contrast agents in proton magnetic resonance imaging, shorten the relaxation times of protons and therefore cause an increase in image intensity in tissues into which they distribute. In this study, the metabolic fate of the nitroxide moiety was examined in the dog using a pyrrolidine nitroxide derivative, 2,2,5,5-tetramethylpyrrolidine-1-oxyl-3-carboxylic acid, for which contrast-enhancing properties have been previously studied in animals. After radiolabeling by microwave discharge in the presence of tritium gas, the compound was administered intravenously to a dog. Ninety-four percent of the radioactivity injected was recovered in urine within 3 days; the majority (90%) was excreted during the first 6 h. The radioactivity in the urine was identified as either the unchanged nitroxide or its corresponding hydroxylamine. Neither complete reduction of the nitroxide moiety to the amine nor any other metabolic transformation was observed.
- Research Organization:
- Univ. of California, San Francisco
- OSTI ID:
- 5712013
- Journal Information:
- Magnet. Reson. Med.; (United States), Journal Name: Magnet. Reson. Med.; (United States) Vol. 5:1; ISSN MRMEE
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
550600 -- Medicine
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BARYONS
CHALCOGENIDES
CONTRAST MEDIA
DISTRIBUTION
DOGS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAGNETIC RESONANCE
MAMMALS
METABOLISM
NITROGEN COMPOUNDS
NITROGEN OXIDES
NUCLEAR MAGNETIC RESONANCE
NUCLEONS
OXIDES
OXYGEN COMPOUNDS
PROTONS
RESONANCE
TISSUE DISTRIBUTION
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES