Department of Biosciences, Federal University of São Paulo, Santos, SP, Brazil.
Physiol Behav. 2011 Jul 6;103(5):487-92. doi: 10.1016/j.physbeh.2011.03.028. Epub 2011 Apr 9.
It has been suggested that access to high caloric food attenuates stress response. The present paper investigates whether access to commercial chow enriched with glucose and fat, here referred to as comfort food alters behavioral, metabolic, and hormonal parameters of rats submitted to three daily sessions of foot-shock stress. Food intake, anxiety-like behaviors, and serum levels of insulin, leptin, corticosterone, glucose and triglycerides were determined. The rats submitted to stress decreased the intake of commercial chow, but kept unaltered the intake of comfort food. During the elevated plus maze (EPM) test, stressed rats increased the number of head dipping, entries into the open arms, as well as the time spent there, and decreased the number of stretched-attend posture and risk assessment. These effects of stress were independent of the type of food consumed. Non-stressed rats ingesting comfort food decreased risk assessment as well. Stress and comfort food increased time spent in the center of the open field and delayed the first crossing to a new quadrant. Stress increased the plasma level of glucose and insulin, and reduced triglycerides, although consumption of comfort food increases glucose, triglyceride and leptin levels; no effect on leptin level was associated to stress. The stress induced increase in serum corticosterone was attenuated when rats had access to comfort food. It was concluded that foot-shock stress has an anorexigenic effect that is independent of leptin and prevented upon access to comfort food. Foot-shock stress also has an anxiolytic effect that is potentiated by the ingestion of comfort food and that is evidenced by both EPM and open field tests.
有人认为，高热量食物的获取会减弱应激反应。本文研究了商业饲料中添加葡萄糖和脂肪（即舒适食物）是否会改变接受每日三次足底电击应激的大鼠的行为、代谢和激素参数。测定了食物摄入量、焦虑样行为以及血清胰岛素、瘦素、皮质酮、葡萄糖和甘油三酯水平。应激大鼠减少了商业饲料的摄入量，但对舒适食物的摄入量保持不变。在高架十字迷宫（EPM）测试中，应激大鼠增加了头部浸入、进入开放臂的次数以及在开放臂停留的时间，减少了伸展姿势和风险评估的次数。这些应激效应与所消耗的食物类型无关。摄入舒适食物的非应激大鼠也减少了风险评估。应激和舒适食物增加了开放场中心的停留时间，并延迟了第一次穿越到新象限。应激增加了血浆葡萄糖和胰岛素水平，并降低了甘油三酯水平，尽管摄入舒适食物会增加葡萄糖、甘油三酯和瘦素水平；但应激与瘦素水平的增加无关。当大鼠可以获得舒适食物时，应激诱导的血清皮质酮水平升高被减弱。结论是，足底电击应激具有厌食作用，与瘦素无关，并可通过摄入舒适食物来预防。足底电击应激还具有抗焦虑作用，这通过 EPM 和开放场测试得到证实，并通过摄入舒适食物得到增强。
