Orexins in rat dorsal motor nucleus of the vagus potently stimulate gastric motor function
Orexins in rat dorsal motor nucleus of the vagus potently stimulate gastric motor function
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DOI：
10.1152/ajpgi.00264.2001
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发表时间：
2002-08-01
影响因子：
4.5
通讯作者：
Hornby, PJ
中科院分区：
文献类型：
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作者：
Krowicki, ZK;Burmeister, MA;Hornby, PJ
食欲素调节食物摄取、唤醒和睡眠-觉醒周期。它们是由下丘脑外侧的神经元合成的，并投射到后脑的自主神经区域。将食欲素A应用于延髓背侧表面，通过迷走神经介导的途径刺激胃酸的分泌。我们验证了迷走神经背侧运动核(DMN)中的食欲素调节胃运动功能的假说。用多支微管组件将载体L-谷氨酸、食欲素A(1和10pmo1)和食欲素B(10pmo1)和染料标记物注入麻醉大鼠的这个部位。当移液管放置在OBEX吻侧的DMN(L-谷氨酸兴奋神经元引起收缩增加的位置)时，食欲素A和B增加胃内压和胃窦运动。相反，向延髓尾侧背核(L-谷氨酸通过迷走神经抑制通路引起胃松弛)微量注射10 pmoL增食欲素A并不显著改变胃运动功能。在单独的免疫细胞化学研究中，食欲素受体1在DMN的神经元中高表达。具体地说，它存在于支配胃的DMN中逆行标记的节前神经元中。这些数据与食欲素A刺激迷走神经兴奋性运动神经元的观点一致。这些数据首次表明，DMN中的食欲素具有增强胃收缩功能的强大而持久的作用。
Orexins regulate food intake, arousal, and the sleep-wake cycle. They are synthesized by neurons in the lateral hypothalamus and project to autonomic areas in the hindbrain. Orexin A applied to the dorsal surface of the medulla stimulates gastric acid secretion via a vagally mediated pathway. We tested the hypothesis that orexins in the dorsal motor nucleus (DMN) of the vagus regulate gastric motor function. Multibarelled micropipette assemblies were used to administer vehicle, L-glutamate, orexins A (1 and 10 pmol) and B (10 pmol), and a dye marker into this site in anesthetized rats. When the pipette was positioned in the DMN rostral to the obex (where excitation of neurons by L-glutamate evoked an increase in contractility), orexins A and B increased intragastric pressure and antral motility. In contrast, 10 pmol orexin A microinjected into the DMN caudal to the obex (where L-glutamate evokes gastric relaxation through a vagal inhibitory pathway) did not significantly alter gastric motor function. In separate immunocytochemical studies, orexin receptor 1 was highly expressed in neurons in the DMN. Specifically, it was present in retrogradely labeled preganglionic neurons in the DMN that innervate the stomach. These data are consistent with the idea that orexin A stimulates vagal excitatory motor neurons. These are the first data to suggest that orexins in the DMN have potent and long-lasting effects to increase gastric contractility.