Tachibana Tetsuya, Sato Momoka, Takahashi Hirokazu, Ukena Kazuyoshi, Tsutsui Kazuyoshi, Furuse Mitsuhiro
Laboratory of Advanced Animal and Marine Bioresources, Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka 812-8581, Japan.
Brain Res. 2005 Jul 19;1050(1-2):94-100. doi: 10.1016/j.brainres.2005.05.035.
Neuropeptides containing a C-terminal Arg-Phe-NH2 motif (RFamide peptides) are suggested to be involved in the control of feeding behavior in both invertebrates and vertebrates. Gonadotropin-inhibitory hormone (GnIH) is the first identified avian RFamide peptide that inhibits gonadotropin release from the pituitary. The GnIH precursor encodes one GnIH and its related peptides (GnIH-RP-1 and -RP-2) that shared the same C-terminal motif, Leu-Pro-Xaa-Arg-Phe-NH2 (Xaa = Leu or Gln) (LPXRFamide). GnIH neurons are localized in the paraventricular nucleus, with their fibers visible in multiple brain locations including the median eminence and brainstem. In this study, we therefore investigated the action of GnIH and its related peptides on feeding behavior. Intracerebroventricular (ICV) injection of GnIH, GnIH-RP-1 and GnIH-RP-2 significantly stimulated food intake in chicks. The chicken pentapeptide LPLRFamide, a degraded C-terminus of GnIH and GnIH-RP-1, did not stimulate feeding thereby demonstrating the importance of the N-terminus of GnIH and its related peptides for the orexigenic effect. Anti-GnIH antiserum suppressed appetite induced by fasting, but did not modify feeding under ad libitum conditions. The present study suggests that GnIH and its related peptides act as endogenous orexigenic factors in the brain of chicks.
含有C末端精氨酸-苯丙氨酸-氨（RFamide肽）基序的神经肽被认为参与无脊椎动物和脊椎动物的摄食行为控制。促性腺激素抑制激素（GnIH）是首个被鉴定出的禽类RFamide肽，它抑制垂体释放促性腺激素。GnIH前体编码一种GnIH及其相关肽（GnIH-RP-1和-RP-2），它们共享相同的C末端基序，即亮氨酸-脯氨酸-Xaa-精氨酸-苯丙氨酸-氨（Xaa = 亮氨酸或谷氨酰胺）（LPXRFamide）。GnIH神经元定位于室旁核，其纤维在包括正中隆起和脑干在内的多个脑区可见。因此，在本研究中，我们研究了GnIH及其相关肽对摄食行为的作用。脑室内（ICV）注射GnIH、GnIH-RP-1和GnIH-RP-显著刺激雏鸡的食物摄入量。鸡五肽LPLRFamide是GnIH和GnIH-RP-1的降解C末端，它不刺激摄食，从而证明了GnIH及其相关肽的N末端对促食欲作用的重要性。抗GnIH抗血清抑制禁食诱导的食欲，但在自由采食条件下不改变摄食情况。本研究表明，GnIH及其相关肽在雏鸡脑中作为内源性促食欲因子发挥作用。
