Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada.
Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; Department of Nuclear Medicine and Radiobiology, Centre d'Imagerie Moléculaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada.
Cell Metab. 2017 Feb 7;25(2):438-447. doi: 10.1016/j.cmet.2016.12.005. Epub 2017 Jan 12.
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 C-acetate and F-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.
来自人体研究的间接证据表明，棕色脂肪组织（BAT）的产热主要由细胞内三酰甘油（TGs）水解产生的脂肪酸提供燃料。然而，目前在人体中尚无直接的实验证据支持这一假设。本研究旨在确定细胞内 TG 在冷暴露男性的 BAT 产热中的作用。我们使用 C-乙酸盐和 F-氟脱氧葡萄糖的正电子发射断层扫描显示，口服烟酸（NiAc），一种细胞内 TG 脂肪分解的抑制剂，抑制了 BAT 氧化代谢和葡萄糖摄取的冷诱导增加，尽管 BAT 血流没有差异。颤抖的强度相应增加，并转向更大程度地依赖糖酵解肌纤维，而不改变总产热量。这些发现表明，细胞内 TG 脂肪分解对于 BAT 产热至关重要，并为 BAT 产热和冷诱导产热中颤抖的相互作用提供了实验证据。
