Scotney Hannah, Symonds Michael E, Law James, Budge Helen, Sharkey Don, Manolopoulos Konstantinos N
Division of Child Health, Obstetrics & Gynaecology, School of Medicine, University of Nottingham, Nottingham, NG7 2UH, UK.
Division of Child Health, Obstetrics & Gynaecology, School of Medicine, University of Nottingham, Nottingham, NG7 2UH, UK; Nottingham Digestive Diseases Biomedical Research Unit, Queens Medical Centre Campus, Nottingham, NG7 2UH.
Metabolism. 2017 May;70:125-132. doi: 10.1016/j.metabol.2017.01.024. Epub 2017 Jan 19.
Brown adipose tissue (BAT) is a thermogenic organ with substantial metabolic capacity and has important roles in the maintenance of body weight and metabolism. Regulation of BAT is primarily mediated through the β-adrenoceptor (β-AR) pathway. The in vivo endocrine regulation of this pathway in humans is unknown. The objective of our study was to assess the in vivo BAT temperature responses to acute glucocorticoid administration.
We studied 8 healthy male volunteers, not pre-selected for BAT presence or activity and without prior BAT cold-activation, on two occasions, following an infusion with hydrocortisone (0.2mg.kg.min for 14h) and saline, respectively. Infusions were given in a randomized double-blind order. They underwent assessment of supraclavicular BAT temperature using infrared thermography following a mixed meal, and during β-AR stimulation with isoprenaline (25ng.kg fat-free mass.min for 60min) in the fasting state.
During hydrocortisone infusion, BAT temperature increased both under fasting basal conditions and during β-AR stimulation. We observed a BAT temperature threshold, which was not exceeded despite maximal β-AR activation. We conclude that BAT thermogenesis is present in humans under near-normal conditions. Glucocorticoids modulate BAT function, representing important physiological endocrine regulation of body temperature at times of acute stress.
棕色脂肪组织（BAT）是一种具有强大代谢能力的产热器官，在维持体重和新陈代谢方面发挥着重要作用。BAT的调节主要通过β-肾上腺素能受体（β-AR）途径介导。该途径在人体内的体内内分泌调节尚不清楚。我们研究的目的是评估急性给予糖皮质激素后体内BAT温度的反应。
我们研究了8名健康男性志愿者，未预先选择是否存在BAT或其活性，且之前未进行过BAT冷激活，分别在两次实验中，依次静脉输注氢化可的松（0.2mg·kg·min，持续14小时）和生理盐水。输注按随机双盲顺序进行。他们在进食混合餐之后，以及在禁食状态下用异丙肾上腺素（25ng·kg去脂体重·min，持续60分钟）刺激β-AR期间，使用红外热成像技术评估锁骨上BAT温度。
在输注氢化可的松期间，无论是在禁食基础条件下还是在β-AR刺激期间，BAT温度均升高。我们观察到一个BAT温度阈值，即使在β-AR最大激活时也未超过该阈值。我们得出结论，在接近正常的条件下，人类体内存在BAT产热。糖皮质激素调节BAT功能，代表了急性应激时体温重要的生理内分泌调节。
