Abstract
18F-FDG PET imaging is routinely used to investigate brown adipose tissue (BAT) thermogenesis which requires mitochondrial uncoupling protein 1 (UCP1). It remains uncertain whether BAT 18F-FDG uptake reliably tracks UCP1-mediated heat production. METHODS: UCP1 knockout (UCP1 KO) and wild-type mice received the selective β3 adrenergic receptor agonist CL 316, 243 (1mg/kg) and underwent metabolic cage, infrared thermal imaging and 18F-FDG PET/magnetic resonance imaging (MRI) experiments. Primary brown adipocytes were additionally examined for their bioenergetics as well as their uptake of 2-deoxy-3H-glucose. RESULTS: In response to CL 316, 243 treatments, oxygen consumption and BAT thermogenesis were diminished in UCP1 KO mice but BAT 18F-FDG uptake was fully retained. UCP1 KO brown adipocytes exhibited defective induction of uncoupled respiration whereas their glycolytic flux and 2-deoxy-3H-glucose uptake rates were largely unaffected. CONCLUSION: Increased BAT 18F-FDG uptake can occur independently of UCP1 function.
- Animal Imaging
- Neuroendocrine
- PET/MRI
- Brown adipose tissue
- Glucose metabolism
- Thermogenesis
- Uncoupling protein 1
- Copyright © 2017 by the Society of Nuclear Medicine and Molecular Imaging, Inc.