Division Livestock-Nutrition-Quality, Department of Biosystems, K.U. Leuven, Kasteelpark Arenberg 30, 3001 Leuven, Belgium.
Gen Comp Endocrinol. 2012 Sep 15;178(3):546-55. doi: 10.1016/j.ygcen.2012.06.026. Epub 2012 Jul 5.
An experiment was conducted to investigate the effects of fasting and re-feeding on hypothalamic 5'-AMP-activated protein kinase (AMPK) levels and (an)orexigenic neuropeptides. Male Arbor Acres chicks (7-day-old, n=160) were allocated to four equal treatment groups: control chicks (fed ad libitum for 48 h, C48), chicks that were fasted for 48 h (F48), chicks that were first fasted for 48 h and then re-fed for 24h (F48C24), and chicks that were fed ad libitum for 72h (C72). Fasting for 48 h significantly (P<0.05) increased the ratio of phosphorylated AMPKα to total AMPKα and phosphorylated LKB1 to total LKB1, whereas re-feeding for 24h reduced these ratios to that of the ad libitum fed C72 chicks. The gene expressions of agouti-related peptide (AgRP), neuropeptide Y (NPY), melanocortin receptor 4, melanin-concentrating hormone, prepro-orexins and carnitine palmitoyltransferase-1 were significantly (P<0.05) increased in the fasted chicks relative to the ad libitum fed C48 group. The gene expression of pro-opiomelanocortin (POMC), as well as cocaine- and amphetamine-regulated transcript (CART) was not affected by the nutritional status. Fasting significantly (P<0.05) decreased the mRNA levels of fatty acid synthase (FAS) and sterol regulatory element binding protein-1 (SREBP-1). The results suggest that the LKB1/AMPK signal pathway is involved in the energy homeostasis of fasted chicks, and its possible role in feed intake regulation might be mediated by the AgRP/NPY rather than the POMC/CART pathway.
一项实验旨在研究禁食和再喂食对下丘脑 5'-AMP 激活蛋白激酶（AMPK）水平和食欲肽的影响。雄性 Arbor Acres 小鸡（7 日龄，n=160）被分配到四个相等的处理组：对照组小鸡（自由喂食 48 小时，C48）、禁食 48 小时的小鸡（F48）、先禁食 48 小时然后再喂食 24 小时的小鸡（F48C24）和自由喂食 72 小时的小鸡（C72）。禁食 48 小时显著（P<0.05）增加了磷酸化 AMPKα 与总 AMPKα 和磷酸化 LKB1 与总 LKB1 的比值，而再喂食 24 小时将这些比值降低至自由喂食的 C72 小鸡的水平。与自由喂食的 C48 组相比，禁食的小鸡中 AgRP、NPY、黑素皮质素受体 4、黑色素浓缩激素、前食欲肽和肉碱棕榈酰转移酶-1 的基因表达显著（P<0.05）增加。POMC 和可卡因和安非他命调节转录物（CART）的基因表达不受营养状态的影响。禁食显著（P<0.05）降低了脂肪酸合酶（FAS）和固醇调节元件结合蛋白-1（SREBP-1）的 mRNA 水平。结果表明，LKB1/AMPK 信号通路参与了禁食小鸡的能量平衡，其在摄食调节中的可能作用可能是通过 AgRP/NPY 途径介导的，而不是通过 POMC/CART 途径。
