Metabolic and Vascular Physiology Laboratory, Baker IDI Heart and Diabetes Institute, PO Box 6492, St Kilda Road Central, Melbourne, VIC 8008, Australia.
Diabetologia. 2013 Jan;56(1):147-55. doi: 10.1007/s00125-012-2748-1. Epub 2012 Oct 13.
AIMS/HYPOTHESIS: Brown adipose tissue (BAT) activation increases energy consumption and may help in the treatment of obesity. Cold exposure is the main physiological stimulus for BAT thermogenesis and the sympathetic nervous system, which innervates BAT, is essential in this process. However, cold-induced BAT activation is impaired in obese humans. To explore the therapeutic potential of BAT, it is essential to determine whether pharmacological agents can activate BAT.
We aimed to determine whether BAT can be activated in lean and obese humans after acute administration of an orally bioavailable sympathomimetic. In a randomised, double-blinded, crossover trial, we administered 2.5 mg/kg of oral ephedrine to nine lean (BMI 22 ± 1 kg/m²) and nine obese (BMI 36 ± 1 kg/m²) young men. On a separate day, a placebo was administered to the same participants. BAT activity was assessed by measuring glucose uptake with [¹⁸F]fluorodeoxyglucose and positron emission tomography-computed tomography imaging.
BAT activity was increased by ephedrine compared with placebo in the lean, but unchanged in the obese, participants. The change in BAT activity after ephedrine compared with placebo was negatively correlated with various indices of body fatness.
CONCLUSIONS/INTERPRETATION: BAT can be activated via acute, oral administration of the sympathomimetic ephedrine in lean, but not in obese humans.
目的/假设：棕色脂肪组织（BAT）的激活增加了能量消耗，可能有助于肥胖的治疗。冷暴露是 BAT 产热的主要生理刺激，支配 BAT 的交感神经系统在此过程中至关重要。然而，肥胖人群的冷诱导 BAT 激活受损。为了探索 BAT 的治疗潜力，必须确定是否可以使用药物激活 BAT。
我们旨在确定在急性给予口服生物利用度的拟交感神经药物后，瘦人和肥胖者的 BAT 是否可以被激活。在一项随机、双盲、交叉试验中，我们给 9 名瘦人（BMI 22 ± 1 kg/m²）和 9 名肥胖者（BMI 36 ± 1 kg/m²）年轻男性口服 2.5 毫克/公斤的麻黄碱。在另一天，相同的参与者接受安慰剂。通过测量 [¹⁸F]氟脱氧葡萄糖摄取和正电子发射断层扫描 - 计算机断层扫描成像来评估 BAT 活性。
与安慰剂相比，BAT 活性在瘦人组中通过麻黄碱增加，但在肥胖组中没有变化。与安慰剂相比，麻黄碱后 BAT 活性的变化与各种体脂指数呈负相关。
结论/解释：在瘦人中，通过急性口服给予拟交感神经麻黄碱可以激活 BAT，但在肥胖人中不行。
