Dietary fat and corticosterone levels are contributing factors to meal anticipation.
Dietary fat and corticosterone levels are contributing factors to meal anticipation.
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DOI：
10.1152/ajpregu.00308.2015
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发表时间：
2016-04-15
期刊：
影响因子：
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通讯作者：
Piggins HD
中科院分区：
文献类型：
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作者：
Namvar S;Gyte A;Denn M;Leighton B;Piggins HD
每天限制食物的获取导致食物预期活动和代谢的发展，这取决于一个尚未确定的食物可消化振荡器。每日限食也会引起循环激素（包括皮质酮）的餐前预期峰值。高脂肪喂养与皮质酮水平升高、昼夜节律紊乱和无法形成强烈的进餐预期有关。目前尚不清楚高脂喂养导致的皮质酮节律紊乱是否会导致高脂喂养大鼠的进餐预期减弱。我们的目的是更好地描述低脂肪或高脂肪饮食大鼠的进餐预期，并更好地了解皮质酮在这一过程中的作用。为此，我们利用行为观察、下丘脑c-Fos表达和间接量热法来评估膳食夹带。我们还使用了糖皮质激素受体拮抗剂，RU 486，解剖出的作用，皮质酮的膳食预期大鼠每天获得不同的脂肪含量。限制低脂饮食导致强烈的进餐预期，以及下丘脑c-Fos表达，代谢和循环皮质酮的夹带。这些措施显着衰减，在响应高脂肪饮食，这种饮食的动物表现出预期皮质酮上升。有趣的是，使用RU 486拮抗糖皮质激素活性减弱了低脂喂养大鼠的进餐预期，但促进了高脂喂养大鼠的进餐预期。这些研究结果表明，皮质酮在调节膳食预期的方式依赖于膳食脂肪含量的重要作用。
Daily restricted access to food leads to the development of food anticipatory activity and metabolism, which depends upon an as yet unidentified food-entrainable oscillator(s). A premeal anticipatory peak in circulating hormones, including corticosterone is also elicited by daily restricted feeding. High-fat feeding is associated with elevated levels of corticosterone with disrupted circadian rhythms and a failure to develop robust meal anticipation. It is not clear whether the disrupted corticosterone rhythm, resulting from high-fat feeding contributes to attenuated meal anticipation in high-fat fed rats. Our aim was to better characterize meal anticipation in rats fed a low- or high-fat diet, and to better understand the role of corticosterone in this process. To this end, we utilized behavioral observations, hypothalamic c-Fos expression, and indirect calorimetry to assess meal entrainment. We also used the glucocorticoid receptor antagonist, RU486, to dissect out the role of corticosterone in meal anticipation in rats given daily access to a meal with different fat content. Restricted access to a low-fat diet led to robust meal anticipation, as well as entrainment of hypothalamic c-Fos expression, metabolism, and circulating corticosterone. These measures were significantly attenuated in response to a high-fat diet, and animals on this diet exhibited a postanticipatory rise in corticosterone. Interestingly, antagonism of glucocorticoid activity using RU486 attenuated meal anticipation in low-fat fed rats, but promoted meal anticipation in high-fat-fed rats. These findings suggest an important role for corticosterone in the regulation of meal anticipation in a manner dependent upon dietary fat content.