Chronic stress promotes palatable feeding, which reduces signs of stress: Feedforward and feedback effects of chronic stress
Chronic stress promotes palatable feeding, which reduces signs of stress: Feedforward and feedback effects of chronic stress
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DOI：
10.1210/en.2004-0305
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发表时间：
2004-08-01
期刊：
影响因子：
4.8
通讯作者：
Dallman, MF
中科院分区：
文献类型：
--
作者：
Pecoraro, N;Reyes, F;Dallman, MF
我们提出了糖皮质激素（GCs）在慢性应激下作用的新模型，其中GCs通过外周能量储存的代谢变化直接刺激大脑活动，同时间接抑制下丘脑-垂体-肾上腺（HPA）轴的活动。这项研究是对我们模型的初步检验。在2 × 2设计中，我们随机提供高热量的猪油和蔗糖（安慰食物）+鼠粮或单独鼠粮，并重复限制每组一半大鼠5 d （3 h/d）。我们测量了限制期间的热量摄入、体重、热效率、ACTH、皮质酮(B)和睾酮，以及瘦素、胰岛素和脂肪储备重量，以及在限制期结束时下丘脑促肾上腺皮质激素释放因子mRNA。我们假设，长期受约束的大鼠会表现出相对增加的安慰食物摄入，并且这些大鼠对重复约束的HPA反应会减少。尽管与对照组相比，受约束的两组大鼠的总热量摄入都有所减少，但与未受约束的对照组相比，受约束的大鼠摄入安慰食物的比例有所增加。此外，有压力的安慰食物组的热量效率得到了恢复。此外，获得安慰食物的大鼠对反复约束的ACTH和B反应降低。与吃鼠粮的对照组相比，吃安慰食物的对照组的促肾上腺皮质激素释放因子mRNA减少，但应激组之间没有差异。本实验的结果倾向于支持我们的压力和gc的慢性效应模型，显示出压力源诱导的对舒适食物的偏好，以及舒适食物对下丘脑轴活动的降低。
We suggested a new model of the effects of glucocorticoids (GCs) exerted during chronic stress, in which GCs directly stimulate activities in the brain while indirectly inhibiting activity in the hypothalamo-pituitary-adrenal (HPA) axis through their metabolic shifts in energy stores in the periphery. This study is an initial test of our model. In a 2 x 2 design, we provided ad lib access to calorically dense lard and sucrose (comfort food) + chow or chow alone, and repeatedly restrained half of the rats in each group for 5 d (3 h/d). We measured caloric intake, body weight, caloric efficiency, ACTH, corticosterone (B), and testosterone during the period of restraint and leptin, insulin, and fat depot weights, as well as hypothalamic corticotropin-releasing factor mRNA at the end of the period. We hypothesized that chronically restrained rats would exhibit a relative increase in comfort food ingestion and that these rats would have reduced HPA responses to repeated restraint. Although total caloric intake was reduced in both groups of restrained rats, compared with controls, the proportion of comfort food ingested increased in the restrained rats compared with their nonrestrained controls. Moreover, caloric efficiency was rescued in the stressed, comfort food group. Furthermore, ACTH and B responses to the repeated restraint bouts were reduced in the rats with access to comfort food. Corticotropin-releasing factor mRNA was reduced in control rats eating comfort food compared with those eating chow, but there were no differences between the stressed groups. The results of this experiment tend to support our model of chronic effects of stress and GCs, showing a stressor-induced preference for comfort food, and a comfort-food reduction in activity of the HPA axis.