Monroe M J, Hornby P J, Partosoedarso E R
Center of Excellence for Neuroscience, Louisiana State University Health Sciences Center, New Orleans, LA, USA.
Neurogastroenterol Motil. 2004 Feb;16(1):5-11. doi: 10.1046/j.1365-2982.2003.00464.x.
We have developed a novel technique to measure gastric volume in vivo in mice; this will be invaluable for revealing gastric alterations in genetically modified mice models, thus expanding our understanding of the mechanisms underlying functional disorders. Experimental data on gastric tone currently available has focused on rats using isovolumetric techniques to measure pressure changes, whereas clinical studies use barostatic techniques to measure volume changes. For better translational approaches, we assessed the feasibility of using a miniaturized barostat to measure gastric volume changes in urethane-anaesthetized and unanaesthetized-decerebrate mice. Additionally, we assessed whether central vagal stimulation alters gastric volume in urethane-anaesthetized mice. Nitric oxide donor sodium nitroprusside (1mg kg-1 i.p.) increased gastric volume (+134 +/- 20 microL), whereas the cholinergic agonist carbachol (3 microg kg-1 i.p.) decreased gastric volume (-153 +/- 20 microL). Similar responses were obtained in urethane-anaesthetized and unanaesthetized-decerebrate animals. Microinjection of L-glutamate (25 nmol) into dorsal motor nucleus of the vagus (DMV) altered gastric volume; microinjection into rostral DMV led to gastric contraction (-83 +/- 18 microL) while stimulation of caudal DMV resulted in gastric relaxation (+95 +/- 16 microL). This reveals a functional organization of DMV in mice. This study validates barostatic techniques for application to mice. An understanding of gastric contractility and tone is clinically relevant as impaired gastric accommodation reflex may be an underlying cause of functional dyspepsia.
我们开发了一种在小鼠体内测量胃容积的新技术；这对于揭示基因改造小鼠模型中的胃部改变将具有极高价值，从而拓展我们对功能紊乱潜在机制的理解。目前可用的关于胃张力的实验数据主要集中在使用等容技术测量压力变化的大鼠身上，而临床研究则使用恒压技术测量容积变化。为了获得更好的转化方法，我们评估了使用小型化恒压器测量氨基甲酸乙酯麻醉和未麻醉去大脑小鼠胃容积变化的可行性。此外，我们评估了中枢迷走神经刺激是否会改变氨基甲酸乙酯麻醉小鼠的胃容积。一氧化氮供体硝普钠（1毫克/千克腹腔注射）可增加胃容积（增加134±20微升），而胆碱能激动剂卡巴胆碱（3微克/千克腹腔注射）则会减少胃容积（减少153±20微升）。在氨基甲酸乙酯麻醉和未麻醉去大脑的动物中均获得了类似的反应。向迷走神经背运动核（DMV）微量注射L-谷氨酸（25纳摩尔）会改变胃容积；向吻侧DMV微量注射会导致胃收缩（减少83±18微升），而刺激尾侧DMV则会导致胃舒张（增加95±16微升）。这揭示了小鼠DMV的功能组织。本研究验证了恒压技术在小鼠中的应用。了解胃收缩性和张力在临床上具有相关性，因为胃容纳反射受损可能是功能性消化不良的潜在原因。
