Hypothalamic Agouti-Related Peptide mRNA is Elevated During Natural and Stress-Induced Anorexia.
Hypothalamic Agouti-Related Peptide mRNA is Elevated During Natural and Stress-Induced Anorexia.
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DOI：
10.1111/jne.12295
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发表时间：
2015-09
影响因子：
3.2
通讯作者：
Boswell T
中科院分区：
文献类型：
--
作者：
Dunn IC;Wilson PW;D'Eath RB;Boswell T
作为自然生活的一部分，动物可能会经历自愿减少食物摄入量和体重的时期（即动物厌食症），这有利于生存或繁殖，例如在领地行为、冬眠、迁徙和卵孵化期间。对于孵化来说，体重防御水平或“滑动设定点”的变化似乎与此有关，尽管对此负责的神经机制尚不清楚。我们研究了家鸡弓状核中的神经肽基因表达如何对孵化后和涉及转移到陌生鸡舍的环境压力源后测量的食物摄入量自愿减少 60-70% 做出反应。我们假设在这些情况下基因表达不会改变，因为食物摄入量和体重的减少代表了自由获取食物的鸟类的防御水平。出乎意料的是，与对照组相比，我们在孵化和转移动物中观察到促食欲肽刺鼠相关肽（AgRP）的基因表达增加。孵化母鸡中阿黑皮质素原 (POMC) mRNA 也较高，并且在暴露于压力源后 6 天显着增加。相反，神经肽 Y 以及可卡因和安非他明调节的转录基因的表达在两种实验情况下都没有变化。我们得出的结论是，AgRP 表达对自然厌食期间的能量储存水平仍然敏感，这具有适应性优势，尽管其正常的食欲促进作用被抑制信号所覆盖。在应激诱发的厌食症中，POMC 的增加可能有助于这种抑制作用，而在孵化过程中，进食减少也可能与下丘脑中促食欲肽血管活性肠肽的表达增加有关。
As part of their natural lives, animals can undergo periods of voluntarily reduced food intake and body weight (i.e. animal anorexias) that are beneficial for survival or breeding, such as during territorial behaviour, hibernation, migration and incubation of eggs. For incubation, a change in the defended level of body weight or ‘sliding set point’ appears to be involved, although the neural mechanisms reponsible for this are unknown. We investigated how neuropeptide gene expression in the arcuate nucleus of the domestic chicken responded to a 60–70% voluntary reduction in food intake measured both after incubation and after an environmental stressor involving transfer to unfamiliar housing. We hypothesised that gene expression would not change in these circumstances because the reduced food intake and body weight represented a defended level in birds with free access to food. Unexpectedly, we observed increased gene expression of the orexigenic peptide agouti‐related peptide (AgRP) in both incubating and transferred animals compared to controls. Also pro‐opiomelanocortin (POMC) mRNA was higher in incubating hens and significantly increased 6 days after exposure to the stressor. Conversely expression of neuropeptide Y and cocaine‐ and amphetamine‐regulated transcript gene was unchanged in both experimental situations. We conclude that AgRP expression remains sensitive to the level of energy stores during natural anorexias, which is of adaptive advantage, although its normal orexigenic effects are over‐ridden by inhibitory signals. In the case of stress‐induced anorexia, increased POMC may contribute to this inhibitory role, whereas, for incubation, reduced feeding may also be associated with increased expression in the hypothalamus of the anorexigenic peptide vasoactive intestinal peptide.