胃动素对大鼠下丘脑胃牵张敏感神经元和胃运动的影响(英文)  

Effect of Motilin on Gastric Distension Sensitive Neurons and Gastric Motility in Rat Hypothalamus

作　　者：赵一方[1] 徐珞[1] 

机构地区：[1]青岛大学医学院病理生理学教研室,山东青岛266021

出　　处：《现代生物医学进展》2010年第3期453-458,共6页Progress in Modern Biomedicine

基　　金：National Natural Science Foundation of China(No.30470642and No.30670780);Shandong Province Tackle Key Problems in Science and Technology Program(2008GG10002006);Qingdao Municipal Scienceand Technology Commission(05-1-JC-93);Shandong province Health Department 266021(2007-37)~~

摘　　要：目的:研究胃动素对下丘脑弓状核胃牵张敏感神经元放电活动和胃运动的影响。方法:采用4管玻璃微电极细胞外记录胃动素对大鼠弓状核胃牵张敏感神经元活动,采用胃内置传感器观察胃动素对对清醒大鼠胃运动的影响。结果:65.5%的弓状核神经元为胃扩张敏感性神经元,其中55.6%为胃扩张兴奋性神经元,44.4%为抑制性神经元。胃扩张刺激后兴奋性神经元的放电频率显著增加(P<0.01),而抑制性神经元的放电频率显著降低(P<0.01)。弓状核内微量注射胃动素,70%的兴奋性神经元在胃扩张刺激后表现为兴奋作用,17.5%的神经元表现为抑制作用,并且放电频率显著增加(P<0.05)。同样,在抑制性神经元中,65.6%在注射胃动素后引起电活动增强,放电频率显著降低(P<0.05)。而胃动素受体拮抗剂GM-109可以完全阻断这种由胃动素诱导的兴奋作用,提示,胃动素在弓状核通过其特异性受体调控神经元活动。在胃运动实验中,弓状核微量注射胃动素后,胃运动的收缩频率和幅度都显著增加(P<0.05);同时,这种兴奋作用也可被GM-109阻断。结论:研究证实了弓状核胃动素神经元接收来自胃感受器的外周躯体感觉传入神经的冲动,并通过某些下级核团通路发挥胃运动的调节作用。Objective： To investigate the effect of motilin on neuronal activity of gastric distension responsive neurons in Arc and to investigate whether motilin can activate pathways in the rat Arc to stimulate gastric motility. Methods： Single unit discharges in the Arc were recorded extracellularly by four-barrel glass micropipettes in anesthetized rats and the effect of motilin on gastric motility was detected by implantation of a force transducer into the stomach in conscious rats. Results： 65.5% of neurons in the Arc responded to GD, 55.6% of which showed excitation （GD-E）, and 44.4% showed inhibition （GD-I）. After gastric distension, the firing rate of the GD-E neurons increased （P〈0.01）, and the firing rate of the GD-I neurons significantly decreased （P〈0.01）. The GD-E neurons in the Arc examined for response to motilin, 70% was activated, 17.5% were depressed, and the firing rate significantly increased after the administration of motilin （P 0.05）. 65.6% GD-I neurons were excited by motilin, their firing rates increased （P 〈0.05）. The motilin-induced responses were abolished by the pretreatment with motilin receptor antagonist GM109. The frequency and amplitude of the gastric contractions significantly increased （P 〈0.05） respectively. However, administration of GM109 abolished the excitatory effect-induced by motilin.Conclusion：Motilin neurons in Arc may accept peripheral somatosensory afferent inputs from gastric mechanoreceptors of the stomach, and may also acts as a stimulatory factor in Arc to regulate gastric motility via some inferior nucleus relay pathway.

关 键 词：胃动素 弓状核 GM-109 胃扩张敏感神经元 胃运动 

分 类 号：Q95-3[生物学—动物学] R338.8[医药卫生—人体生理学]