Orexin在隔核对大鼠胃传入信息的调控

目的:研究orexin在隔核对大鼠胃传入信息的调控作用。方法:选取健康成年雄性Wistar大鼠138只(体质量250-300 g),记录神经元放电活动,鉴定隔核胃牵张(GD)敏感性神经元;隔核微量注射orexin-A或orexin-A受体拮抗剂SB334867,观察隔核GD敏感性神经元放电活动变化;隔核微量注射不同浓度的orexin-A,观察大鼠胃运动的变化。结果:隔核微量注射orexin-A的大鼠胃运动幅度和频率显著增加,并呈剂量依赖关系(P0.05-0.01),微量注射SB-334867可完全阻断orexin-A对胃运动的影响。隔核微量注射orexin-A后,有36个GD-E神经元兴奋(P0.01),16个GD-I神经元抑制。Orexin-A受体拮抗剂SB334867可完全阻断orexin-A对GD敏感神经元的作用。结论:隔核注射orexin能促进大鼠胃运动,并影响胃牵张敏感神经元的放电活动。

Regulation of Orexin on the Gastric Afferent Information in Rats

ABSTRACT Objective: To study the regulation of orexin on the gastric afferent information in the septal nuclei of rats. Methods: 138 adult male Wistar rats weighed 250-300 g were selected, extracellular discharges of single unit neuron in the septal nuclei were used to identify the gastric distension(GD) sensitive neurons. Microinjection of orexin-A or orexin-A receptor antagonist SB334867 into septal nuclei was performed to explore the changes of GD sensitive neurons in the septal nuclei. The effects of different concentrations of orex- in-A on the gastric motility of rats were observed. Results: The gastric motility experiments showed that administration of orexin-A in the septal nuclei could significantly increase the amplitude and frequency of gastric motility in a dose-dependent manner(P<0.05-0.01). Mi- croinjection of SB-334867 could completely block the effect of orexin-A on the gastric motility. After the septal nuclei Microinjection of orexin-A, there were 36 GD excitatory (GD-E) neurons and 16 GD inhibitory (GD-I) neurons. The effects induced by orexin-A on GD sensitive neurons were completely abolished with administration of SB-334867. Conclusion: Injection of orexin into the septal nuclei could promote the gastric motility in rats and also change the discharge activity of gastric distention (GD) sensitive neurons.