Hewagalamulage S D, Lee T K, Clarke I J, Henry B A
Department of Physiology, Monash University, VIC 3800, Australia.
Department of Physiology, Monash University, VIC 3800, Australia.
Domest Anim Endocrinol. 2016 Jul;56 Suppl:S112-20. doi: 10.1016/j.domaniend.2016.03.004. Epub 2016 Mar 31.
There is a strong inter-relationship between activation of the hypothalamo-pituitary-adrenal axis and energy homeostasis. Patients with abdominal obesity have elevated cortisol levels. Furthermore, stress and glucocorticoids act to control both food intake and energy expenditure. In particular, glucocorticoids are known to increase the consumption of foods enriched in fat and sugar. It is well-known that, in all species, the cortisol response to stress or adrenocorticotropin is highly variable. It has now emerged that cortisol responsiveness is an important determinant in the metabolic sequelae to stress. Sheep that are characterized as high-cortisol responders (HRs) have greater propensity to weight gain and obesity than low-cortisol responders (LRs). This difference in susceptibility to become obese is associated with a distinct metabolic, neuroendocrine, and behavioral phenotype. In women and ewes, HR individuals eat more in response to stress than LR. Furthermore, HR sheep have impaired melanocortin signaling and reduced skeletal muscle thermogenesis. High-cortisol responder sheep exhibit reactive coping strategies, whereas LRs exhibit proactive coping strategies. This complex set of traits leads to increased food intake and reduced energy expenditure in HR and thus, predisposition to obesity. We predict that cortisol responsiveness may be used as a marker to identify individuals who are at risk of weight gain and subsequent obesity.
下丘脑 - 垂体 - 肾上腺轴的激活与能量稳态之间存在着紧密的相互关系。腹部肥胖患者的皮质醇水平升高。此外，应激和糖皮质激素对食物摄入和能量消耗均有调控作用。特别是，已知糖皮质激素会增加富含脂肪和糖的食物的消耗量。众所周知，在所有物种中，皮质醇对应激或促肾上腺皮质激素的反应具有高度变异性。现在已经发现，皮质醇反应性是应激代谢后遗症的一个重要决定因素。具有高皮质醇反应性（HR）特征的绵羊比低皮质醇反应性（LR）的绵羊更易体重增加和肥胖。这种肥胖易感性的差异与独特的代谢、神经内分泌和行为表型有关。在女性和母羊中，HR个体对应激的进食量比LR个体多。此外，HR绵羊的黑皮质素信号传导受损，骨骼肌产热减少。高皮质醇反应性绵羊表现出反应性应对策略，而LR绵羊表现出主动性应对策略。这一系列复杂的特征导致HR个体食物摄入量增加、能量消耗减少，从而易患肥胖症。我们预测，皮质醇反应性可用作识别有体重增加及后续肥胖风险个体的标志物。
