Division of Integrative Physiology, Department of Physiology, Jichi Medical University School of Medicine, Shimotsuke, Tochigi 329-0498, Japan.
Curr Pharm Des. 2012;18(31):4854-64. doi: 10.2174/138161212803216898.
Ghrelin is the orexigenic peptide produced in the periphery, and its plasma level shows remarkable pre/postprandial changes. Ghrelin is considered a pivotal signal to the brain to stimulate feeding. Hence, characterizing the target neurons for ghrelin in the hypothalamic feeding center and the signaling cascade in the target neurons are essential for understanding the mechanisms regulating appetite. Anorexia and cachexia associated with gastric surgery, stress-related diseases, and use of anti-cancer drugs cause the health problems, markedly deteriorating the quality of life. The anorexia involves several neurotransmitters and neuropeptides in the hypothalamic feeding center, in which corticotropin-releasing hormone (CRH), urocortine, serotonin (5HT) and brain-derived neurotrophic factor (BDNF) play a pivotal role. A Japanese herbal medicine, rikkunshito, has been reported to ameliorate the anorexia by promoting the appetite. This review describes 1) the interaction of ghrelin with the orexigenic neuropeptide Y (NPY) neurons in the hypothalamic arcuate nucleus (ARC) and underlying signaling cascade in NPY neurons, 2) the anorectic pathway driven by BDNF-CRH/urocortine and 5HTCRH/ urocortine pathways, 3) the effect of rikkunshito on the interaction of ghrelin and NPY neurons in ARC, and 4) the effect of rikkunshito on the interaction of 5HT on CRH neurons in paraventricular nucleus (PVN).
胃饥饿素是外周产生的食欲肽，其血浆水平显示出显著的餐前/餐后变化。胃饥饿素被认为是向大脑发出刺激进食的关键信号。因此，描述下丘脑摄食中枢中胃饥饿素的靶神经元及其在靶神经元中的信号级联对于理解调节食欲的机制至关重要。与胃切除术、应激相关疾病和抗癌药物使用相关的厌食症和恶病质会导致健康问题，显著降低生活质量。这种厌食症涉及下丘脑摄食中枢中的几种神经递质和神经肽，其中促肾上腺皮质激素释放激素 (CRH)、尿皮质素、5-羟色胺 (5HT) 和脑源性神经营养因子 (BDNF) 起着关键作用。一种日本草药，利克肠，已被报道通过促进食欲来改善厌食症。这篇综述描述了 1) 胃饥饿素与下丘脑弓状核 (ARC) 中食欲肽神经肽 Y (NPY) 神经元的相互作用及其在 NPY 神经元中的潜在信号级联，2) BDNF-CRH/尿皮质素和 5HTCRH/尿皮质素途径驱动的厌食症途径，3) rikkunshito 对 ARC 中胃饥饿素和 NPY 神经元相互作用的影响，以及 4) rikkunshito 对 5HT 对室旁核 (PVN) CRH 神经元相互作用的影响。
