Abstract 12690: Comparison of 68Ga and 64Cu for Molecular Imaging of Atherosclerosis using apo A-I Mimetic Peptide FAMP
Background: Molecular imaging for the detection of atheromatous plaque burden is highlighted as a modality for the diagnosis of atherosclerosis. Since the physical interactions between apoA-I and ABCA1 modulate not only binding to apoA-I, but also internalization and transcytosis in macrophages and aortic endothelial cells, apo A-I mimetic peptide may be a candidate for functional HDL imaging in atherosclerosis.
Methods and Results: Rabbits were intravenously injected with FAMP, a newly developed apoA-I mimetic peptide radiolabeled with 68Ga-DOTA or 64Cu-TE2A, and subjected (25-30Mbq) to positron emission tomography (PET) for continuously. 68Ga-DOTA-FAMP was dramatically taken up by atherosclerotic lesions of the aorta (Fig. B) in myocardial infarction-prone Watanabe heritable hyperlipidemic rabbits (WHHL-MI, n=4), but not in normal rabbits (JW, n=4, Fig A). In contrast, 64Cu- TE2A-FAMP was not illuminated in the aorta of either normal or atherosclerotic rabbits (Fig. C and D, respectively). Moreover, 64Cu- TE2A-FAMP was rapidly breaking down and 64Cu was excreted to the intestine, liver or bladder in both rabbits. In contrast to the results with 68Ga-DOTA[[Unable to Display Character: —]]FAMP, we did not observe any illuminated aorta in either rabbit with scramble-FAMP.
Conclusions: These results demonstrated that apo A-I mimetic peptide (FAMP) is a specific target molecule for atherosclerotic molecular imaging with 68Ga-DOTA, but not with 64Cu- TE2A. The selection of a suitable nucleus and chelators should be important for HDL functioning imaging.
- © 2013 by American Heart Association, Inc.