Helwig Michael, Archer Zoë A, Heldmaier Gerhard, Tups Alexander, Mercer Julian G, Klingenspor Martin
Molecular Nutritional Medicine, Else Kröner-Fresenius Center, Technische Universität München, Am Forum 5, 85350, Freising-Weihenstephan, Germany.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2009 Jul;195(7):631-42. doi: 10.1007/s00359-009-0438-3. Epub 2009 Apr 5.
Central regulation of energy balance in seasonal mammals such as the Siberian hamster is dependent on the precise integration of short-term satiety information arising from the gastrointestinal tract with long-term signals on the status of available energy reserves (e.g. leptin) and prevailing photoperiod. Within the central nervous system, the brainstem nucleus of the solitary tract (NTS) and the parabrachial nucleus (PBN) are major relay nuclei that transmit information from the gastrointestinal tract to higher forebrain centres. We extended studies on the seasonal programming of the hypothalamus to examine the effect of the photoperiod on neuropeptidergic circuitries of this gut-brain axis. In the NTS and PBN we performed gene expression and immunoreactivity (-ir) studies on selected satiety-related neuropeptides and receptors: alpha-melanocyte stimulating hormone, melanocortin-3 receptor, melanocortin-4 receptor (MC4-R), growth hormone secretagogue-receptor, cocaine- and amphetamine-regulated transcript, preproglucagon (PPG), glucagon-like peptide 1 (GLP-1), cholecystokinin (CCK), peptide YY, galanin, neurotensin, and corticotrophin releasing hormone (CRH). Gene expression of PPG and MC4-R, and -ir of CCK and GLP-1, in the NTS were up-regulated after 14 weeks in long-day photoperiod (16 h light:8 h dark) compared to short-days (8 h light:16 h dark), whereas CRH-ir and NT-ir were increased in short-days within the PBN. We suggest that brainstem neuroendocrine mechanisms contribute to the long-term regulation of body mass in the Siberian hamster by a photoperiod-related modulation of satiety signalling.
在诸如西伯利亚仓鼠等季节性哺乳动物中,能量平衡的中枢调节依赖于来自胃肠道的短期饱腹感信息与可用能量储备状态(如瘦素)及当前光周期的长期信号的精确整合。在中枢神经系统内,孤束核(NTS)和臂旁核(PBN)是主要的中继核,它们将来自胃肠道的信息传递至更高位的前脑中枢。我们扩展了对下丘脑季节性编程的研究,以检验光周期对这条肠-脑轴神经肽能回路的影响。在NTS和PBN中,我们对选定的与饱腹感相关的神经肽和受体进行了基因表达和免疫反应性(-ir)研究:α-黑素细胞刺激素、黑皮质素-3受体、黑皮质素-4受体(MC4-R)、生长激素促分泌素受体、可卡因和苯丙胺调节转录物、前胰高血糖素原(PPG)、胰高血糖素样肽1(GLP-1)、胆囊收缩素(CCK)、肽YY、甘丙肽、神经降压素和促肾上腺皮质激素释放激素(CRH)。与短日照(8小时光照:16小时黑暗)相比,长日照光周期(16小时光照:8小时黑暗)14周后,NTS中PPG和MC4-R的基因表达以及CCK和GLP-1的免疫反应性上调,而PBN内短日照时CRH免疫反应性和NT免疫反应性增加。我们认为,脑干神经内分泌机制通过与光周期相关的饱腹感信号调节,对西伯利亚仓鼠体重的长期调节起作用。