IMPY, a potential beta-amyloid imaging probe for detection of prion deposits in scrapie-infected mice.

Abstract

INTRODUCTION:

A potential single-photon emission computed tomography imaging agent for labeling of A beta plaques of Alzheimer's disease, IMPY (2-(4'-dimethylaminophenyl)-6-iodo-imidazo[1,2-a]pyridine), would be effective in detection of prion amyloid deposits in transmissible spongiform encephalopathies (TSEs).

METHODS:

In vitro autoradiographic studies were carried out with [125 I]IMPY on brain sections from scrapie-infected mice and age-matched controls. Competition study was performed to evaluate the prion deposit binding specificity with nonradioactive IMPY.

RESULTS:

Binding of [125 I]IMPY was observed in infected brain sections, while on age-matched control brain sections, there was no or very low labeling. Prion deposit binding was confirmed by histoblots with prion protein-specific monoclonal antibody 2D6. In the presence of nonradioactive IMPY, the binding of [125 I]IMPY was significantly inhibited in all regions studied.

CONCLUSIONS:

These findings indicate that IMPY can detect the prion deposits in vitro in scrapie-infected mice. Labeled with 123 I, this ligand may be useful to quantitate prion deposit burdens in TSEs by in vivo imaging.

• Authors: Pu-Jiao Song, Serge Bernard, Pierre Sarradin, Jackie Vergote, Céline Barc, Sylvie Chalon, Mei-Ping Kung, Hank F Kung, Denis Guilloteau
• Journal: Nuclear medicine and biology (Nucl Med Biol) Vol. 35 Issue 2 Pg. 197-201 (Feb 2008) ISSN: 0969-8051 [Print] United States
• PMID: 18312829 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Amyloid beta-Peptides
• Antibodies, Monoclonal
• Iodine Radioisotopes
• Prions
• Pyrazoles
• Radiopharmaceuticals
• 2,3-dihydro-1H-imidazo(1,2-b)pyrazole

Topics

• Alzheimer Disease (diagnostic imaging, pathology)
• Amyloid beta-Peptides (chemistry)
• Animals
• Antibodies, Monoclonal (chemistry)
• Autoradiography
• Binding, Competitive
• Brain (diagnostic imaging, pathology)
• Disease Models, Animal
• Humans
• Iodine Radioisotopes (pharmacokinetics)
• Isotope Labeling (methods)
• Mice
• Plaque, Amyloid (diagnostic imaging, pathology)
• Prions (chemistry)
• Pyrazoles (pharmacokinetics)
• Radionuclide Imaging
• Radiopharmaceuticals (pharmacokinetics)
• Scrapie (diagnostic imaging, pathology)