Published in:
01-10-2011 | Research Article
Pancreatic Beta Cell Mass PET Imaging and Quantification with [11C]DTBZ and [18F]FP-(+)-DTBZ in Rodent Models of Diabetes
Authors:
Tarun Singhal, Yu-Shin Ding, David Weinzimmer, Marc D. Normandin, David Labaree, Jim Ropchan, Nabeel Nabulsi, Shu-fei Lin, Marc B. Skaddan, Walter C. Soeller, Yiyun Huang, Richard E. Carson, Judith L. Treadway, Gary W. Cline
Published in:
Molecular Imaging and Biology
|
Issue 5/2011
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Abstract
Purpose
The aim of this study is to compare the utility of two positron emission tomography (PET) imaging ligands ((+)-[11C]dihydrotetrabenazine ([11C]DTBZ) and the fluoropropyl analog ([18F]FP-(+)-DTBZ)) that target islet β-cell vesicular monoamine transporter type II to measure pancreatic β-cell mass (BCM).
Procedures
[11C]DTBZ or [18F]FP-(+)-DTBZ was injected, and serial PET images were acquired in rat models of diabetes (streptozotocin-treated and Zucker diabetic fatty) and β-cell compensation (Zucker fatty). Radiotracer standardized uptake values (SUV) were correlated to pancreas insulin content measured biochemically and histomorphometrically.
Results
On a group level, a positive correlation of [11C]DTBZ pancreatic SUV with pancreas insulin content and BCM was observed. In the STZ diabetic model, both [18F]FP-(+)-DTBZ and [11C]DTBZ correlated positively with BCM, although only ∼25% of uptake could be attributed to β-cell uptake. [18F]FP-(+)-DTBZ displacement studies indicate that there is a substantial fraction of specific binding that is not to pancreatic islet β cells.
Conclusions
PET imaging with [18F]FP-(+)-DTBZ provides a noninvasive means to quantify insulin-positive BCM and may prove valuable as a diagnostic tool in assessing treatments to maintain or restore BCM.