Inhibition of Intracellular Triglyceride Lipolysis Suppresses Cold-Induced Brown Adipose Tissue Metabolism and Increases Shivering in Humans

Publication date: Available online 12 January 2017
Source:Cell Metabolism
Author(s): Denis P. Blondin, Frédérique Frisch, Serge Phoenix, Brigitte Guérin, Éric E. Turcotte, François Haman, Denis Richard, André C. Carpentier
Indirect evidence from human studies suggests that brown adipose tissue (BAT) thermogenesis is fueled predominantly by fatty acids hydrolyzed from intracellular triglycerides (TGs). However, no direct experimental evidence to support this assumption currently exists in humans. The aim of this study was to determine the role of intracellular TG in BAT thermogenesis, in cold-exposed men. Using positron emission tomography with ¹¹C-acetate and ¹⁸F-fluorodeoxyglucose, we showed that oral nicotinic acid (NiAc) administration, an inhibitor of intracellular TG lipolysis, suppressed the cold-induced increase in BAT oxidative metabolism and glucose uptake, despite no difference in BAT blood flow. There was a commensurate increase in shivering intensity and shift toward a greater reliance on glycolytic muscle fibers without modifying total heat production. Together, these findings show that intracellular TG lipolysis is critical for BAT thermogenesis and provides experimental evidence for a reciprocal role of BAT thermogenesis and shivering in cold-induced thermogenesis in humans.

Graphical abstract

Teaser

Blondin et al. use PET imaging in humans to demonstrate that brown adipose tissue uses lipids as its cellular fuel source for thermogenesis. Inhibition of intracellular TG lipolysis resulted in suppressed BAT thermogenesis, which was offset by an increase in shivering intensity.


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