Hao Heling, Luan Xiao, Guo Feifei, Sun Xiangrong, Gong Yanling, Xu Luo
Department of Pathophysiology, Medical College of Qingdao University, Qingdao, Shandong 266021, PR China.
Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, Shandong, PR China.
Neuropeptides. 2016 Jun;57:45-52. doi: 10.1016/j.npep.2016.02.005. Epub 2016 Feb 16.
The orexins system consists of two G-protein coupled receptors (the orexin-1 and the orexin-2 receptor) and two neuropeptides, orexin-A and orexin-B. Orexin-A is an excitatory neuropeptide that regulates arousal, wakefulness and appetite. Recent studies have shown that orexin-A may promote gastric motility. We aim to explore the effects of orexin-A on the gastric -distension (GD) sensitive neurons and gastric motility in the lateral hypothalamic area (LHA), and the possible regulation by the paraventricular nucleus (PVN). Extracellular single unit discharges were recorded and the gastric motility was monitored by administration of orexin-A into the LHA and electrical stimulation of the PVN. There were GD neurons in the LHA, and administration of orexin-A to the LHA could increase the firing rate of both GD-excitatory (GD-E) and GD-inhibited (GD-I) neurons. The gastric motility was significantly enhanced by injection of orexin-A into the LHA with a dose dependent manner, which could be completely abolished by pre-treatment with orexin-A receptor antagonist SB334867. Electrical stimulation of the PVN could significantly increase the firing rate of GD neurons responsive to orexin-A in the LHA as well as promote gastric motility of rats. However, those effects could be partly blocked by pre-treatment with SB334867 in the LHA. It is suggested that orexin-A plays an important role in promoting gastric motility via LHA. The PVN may be involved in regulation of LHA on gastric motility.
食欲素系统由两种G蛋白偶联受体（食欲素-1和食欲素-2受体）以及两种神经肽——食欲素-A和食欲素-B组成。食欲素-A是一种兴奋性神经肽，可调节觉醒、清醒状态和食欲。最近的研究表明，食欲素-A可能促进胃动力。我们旨在探讨食欲素-A对下丘脑外侧区（LHA）胃扩张（GD）敏感神经元和胃动力的影响，以及室旁核（PVN）可能的调节作用。通过向LHA注射食欲素-A和电刺激PVN来记录细胞外单单位放电并监测胃动力。LHA中存在GD神经元，向LHA注射食欲素-A可增加GD兴奋性（GD-E）和GD抑制性（GD-I）神经元的放电频率。向LHA注射食欲素-A可显著增强胃动力，且呈剂量依赖性，预先用食欲素-A受体拮抗剂SB334867处理可完全消除这种增强作用。电刺激PVN可显著增加LHA中对食欲素-A有反应的GD神经元的放电频率，并促进大鼠的胃动力。然而，在LHA中预先用SB334867处理可部分阻断这些作用。提示食欲素-A通过LHA在促进胃动力方面发挥重要作用。PVN可能参与LHA对胃动力的调节。
