Department of Radiology, Royal Infirmary of Edinburgh, Edinburgh, Scotland, UK.
BHF/University Centre for Cardiovascular Science, University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, Scotland, UK.
Cell Metab. 2018 Jun 5;27(6):1348-1355.e4. doi: 10.1016/j.cmet.2018.04.020. Epub 2018 May 24.
Current understanding of in vivo human brown adipose tissue (BAT) physiology is limited by a reliance on positron emission tomography (PET)/computed tomography (CT) scanning, which has measured exogenous glucose and fatty acid uptake but not quantified endogenous substrate utilization by BAT. Six lean, healthy men underwent fluorodeoxyglucose-PET/CT scanning to localize BAT so microdialysis catheters could be inserted in supraclavicular BAT under CT guidance and in abdominal subcutaneous white adipose tissue (WAT). Arterial and dialysate samples were collected during warm (∼25°C) and cold exposure (∼17°C), and blood flow was measured by xenon washout. During warm conditions, there was increased glucose uptake and lactate release and decreased glycerol release by BAT compared with WAT. Cold exposure increased blood flow, glycerol release, and glucose and glutamate uptake only by BAT. This novel use of microdialysis reveals that human BAT is metabolically active during warm conditions. BAT activation substantially increases local lipolysis but also utilization of other substrates such as glutamate.
目前对于体内人类棕色脂肪组织（BAT）生理学的认识受到了一定限制，这是因为依赖于正电子发射断层扫描（PET）/计算机断层扫描（CT）扫描，该扫描方法测量了外源性葡萄糖和脂肪酸的摄取量，但并未定量测定 BAT 内源性底物的利用情况。6 名健康的瘦人接受了氟脱氧葡萄糖-PET/CT 扫描以定位 BAT，以便在 CT 引导下将微透析导管插入锁骨上 BAT 和腹部皮下白色脂肪组织（WAT）中。在温暖（约 25°C）和寒冷暴露（约 17°C）期间收集动脉和透析液样本，并通过氙气冲洗测量血流。在温暖条件下，与 WAT 相比，BAT 的葡萄糖摄取和乳酸释放增加，而甘油释放减少。仅在 BAT 中，寒冷暴露增加了血流、甘油释放以及葡萄糖和谷氨酸的摄取。这种微透析的新用途表明，人类 BAT 在温暖条件下具有代谢活性。BAT 的激活大大增加了局部脂肪分解，但也增加了其他底物（如谷氨酸）的利用。
