Abstract
Brown adipose tissue (BAT) differs from white adipose tissue (WAT) by its discrete location and a brown-red color due to rich vascularization and high density of mitochondria. BAT plays a major role in energy expenditure and non-shivering thermogenesis in newborn mammals as well as the adults 1. BAT-mediated thermogenesis is highly regulated by the sympathetic nervous system, predominantly viaβ adrenergic receptor 2, 3. Recent studies have shown that BAT activities in human adults are negatively correlated with body mass index (BMI) and other diabetic parameters 4- 6. BAT has thus been proposed as a potential target for anti-obesity/anti-diabetes therapy focusing on modulation of energy balance 6- 8. While several cold challenge-based positron emission tomography (PET) methods are established for detecting human BAT 9- 13, there is essentially no standardized protocol for imaging and quantification of BAT in small animal models such as mice. Here we describe a robust PET/CT imaging method for functional assessment of BAT in mice. Briefly, adult C57BL/6J mice were cold treated under fasting conditions for a duration of 4 hours before they received one dose of 18F-Fluorodeoxyglucose (FDG). The mice were remained in the cold for one additional hour post FDG injection, and then scanned with a small animal-dedicated micro-PET/CT system. The acquired PET images were co-registered with the CT images for anatomical references and analyzed for FDG uptake in the interscapular BAT area to present BAT activity. This standardized cold-treatment and imaging protocol has been validated through testing BAT activities during pharmacological interventions, for example, the suppressed BAT activation by the treatment of β-adrenoceptor antagonist propranolol 14, 15, or the enhanced BAT activation by β3 agonist BRL37344 16. The method described here can be applied to screen for drugs/compounds that modulate BAT activity, or to identify genes/pathways that are involved in BAT development and regulation in various preclinical and basic studies.
Original language | English |
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Article number | e4060 |
Journal | Journal of Visualized Experiments |
Issue number | 69 |
DOIs | |
State | Published - Dec 6 2012 |
Keywords
- 18F-Fluorodeoxyglucose
- Anatomy
- Brown adipose tissue
- CT
- CT scan
- Imaging
- Issue 69
- Medicine
- Mice
- Micro-PET
- Molecular biology
- Neuroscience
- PET
- Physiology
- Tomography
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Chemical Engineering(all)
- Immunology and Microbiology(all)
- Neuroscience(all)