Differential feeding responses to central alpha-melanocyte stimulating hormone in genetically low and high body weight selected lines of chickens
Differential feeding responses to central alpha-melanocyte stimulating hormone in genetically low and high body weight selected lines of chickens
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DOI：
10.1016/j.lfs.2008.06.003
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发表时间：
2008-08-01
期刊：
影响因子：
6.1
通讯作者：
Siegel, Paul B.
中科院分区：
文献类型：
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作者：
Cline, Mark A.;Nandar, Wint;Siegel, Paul B.
本研究旨在比较中枢α-MSH（一种有效的促凋亡信号）在经历长期低体重（LWS）或高体重（HWS）趋异选择的鸡品系中的作用。从两个线的小鸡集中注射0，24，120或600 pmol的α-MSH和饲料和水的摄入量，此后同时测量共180分钟。LWS线响应所有剂量的α-MSH在所有观察时间的饲料摄入量类似的有效减少。HWS系仅对600 pmol alpha-MSH有反应，摄食量降低。α-MSH不影响两条线的饮水量。为了确定差异下丘脑信号传导是否与促食欲作用相关，在600 pmol中枢α-MSH注射后测量食欲相关下丘脑核团中的c-Fos免疫反应性。α-MSH后，两种品系下丘脑背内侧核、室旁核（PVN）和腹内侧核的c-Fos免疫反应性均增加;然而，LWS中PVN的增加幅度大于HWS鸡（分别比对照组增加136%和47%）。基于行为观察，在LWS系中，在α-MSH之后，进食和探索性啄的次数以更大的幅度减少。此外，α-MSH与两条线的深度休息增加有关，可能是减少摄入的次要影响。这些数据支持LWS系具有较低的中枢α-MSH的促凋亡作用阈值，而在HWS系中该阈值较高，并且该差异可能与差异下丘脑信号传导相关。在LWS和HWS系鸡中，中枢α-MSH的致突变反应阈值存在遗传变异，可能对包括人类在内的其他物种产生影响。(C)2008年爱思唯尔公司All rights reserved.
This study was conducted to compare the effects of central alpha-MSH, a potent anorexigenic signal, in lines of chickens that have undergone long-term divergent selection for low (LWS) or high (HWS) body weight. Chicks from both lines were centrally injected with 0, 24,120 or 600 pmol alpha-MSH and feed and water intake were concurrently measured thereafter for a total of 180 min. The LWS line responded to all doses of alpha-MSH with a similar potent decrease in feed intake at all observation times. The HWS line only responded to 600 pmol alpha-MSH with decreased feed intake. alpha-MSH did not influence water intake in either line. To determine if differential hypothalamic signaling was associated with the anorexigenic effect, c-Fos immunoreactivity was measured in appetite-related hypothalamic nuclei after 600 pmol central alpha-MSH injections. c-Fos immunoreactivity was increased in the dorsomedial hypothalamus, paraventricular nucleus (PVN) and ventromediall hypothalamus in both lines after alpha-MSH; however, the magnitude of increase was greater in LWS than in HWS chicks at the PVN (136% vs. 47% increase over controls, respectively). Based on behavior observations, the number of feeding and exploratory pecks is decreased with greater magnitude after alpha-MSH in the LWS line. Additionally, alpha-MSH was associated with increased deep rest in both lines, and may be a secondary effect to reduced ingestion. These data support that the LWS line has a lower threshold for the anorexigenic effect of central alpha-MSH while in the HWS line this threshold is higher, and that this difference may be associated with differential hypothalamic signaling. Genetic variation exists in the threshold of anorexigenic response for central alpha-MSH in LWS and HWS lines of chickens with possible implications to other species including humans. (C) 2008 Elsevier Inc. All rights reserved.