Format

Send to:

Choose Destination
See comment in PubMed Commons below
Nucl Med Biol. 2012 Oct;39(7):1081-6. doi: 10.1016/j.nucmedbio.2012.04.005. Epub 2012 May 16.

Ex vivo and in vivo evaluation of the norepinephrine transporter ligand [11C]MRB for brown adipose tissue imaging.

Author information

  • 1PET Center, Department of Diagnostic Radiology, Yale University, New Haven, CT 06520, USA.

Abstract

INTRODUCTION:

It has been suggested that brown adipose tissue (BAT) in humans may play a role in energy balance and obesity. We conducted ex vivo and in vivo evaluation using [(11)C]MRB, a highly selective NET (norepinephrine transporter) ligand for BAT imaging at room temperature, which is not achievable with [(18)F]FDG.

METHODS:

PET images of male Sprague-Dawley rats with [(18)F]FDG and [(11)C]MRB were compared. Relative [(18)F]FDG or [(11)C]MRB retention at 20, 40 and 60 min post-injection was quantified on awake rats after exposing to cold (4°C for 4h) or remaining at room temperature. Rats pretreated with unlabeled MRB or nisoxetine 30 min before [(11)C]MRB injection were also assessed. The [(11)C]MRB metabolite profile in BAT was evaluated.

RESULTS:

PET imaging demonstrated intense [(11)C]MRB uptake (SUV of 2.9 to 3.3) in the interscapular BAT of both room temperature and cold-exposed rats and this uptake was significantly diminished by pretreatment with unlabeled MRB; in contrast, [(18)F]FDG in BAT was only detected in rats treated with cold. Ex vivo results were concordant with the imaging findings; i.e. the uptake of [(11)C]MRB in BAT was 3 times higher than that of [(18)F]FDG at room temperature (P=0.009), and the significant cold-stimulated uptake in BAT with [(18)F]FDG (10-fold, P=0.001) was not observed with [(11)C]MRB (P=0.082). HPLC analysis revealed 94%-99% of total radioactivity in BAT represented unchanged [(11)C]MRB.

CONCLUSIONS:

Our study demonstrates that BAT could be specifically labeled with [(11)C]MRB at room temperature and under cold conditions, supporting a NET-PET strategy for imaging BAT in humans under basal conditions.

Copyright © 2012 Elsevier Inc. All rights reserved.

PMID:
22595487
[PubMed - indexed for MEDLINE]
PMCID:
PMC4067762
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Write to the Help Desk