生长素对胃运动和对海马胃肠敏感神经元放电活动的影响

The Effects of Ghrelin on Gastric Motility and the Activity of Gastrointestinal Sensitive Neurons in the Hippocampus and the Regulation of Hypothalamic Hormones

目的:探讨海马ghrelin对GD敏感神经元放电和弓状核ghrelin对胃运动的影响。方法:在细胞外记录海马的放电情况,并且检测清醒大鼠的胃运动。通过PCR免疫印迹和免疫荧光组织化学染色等方法来测定GHSR-1a在海马中的表达。用逆行追踪和免疫荧光组织化学染色检测ghrelin神经元的投射情况。Ghrelin况荧光金双标记的神经元以及GHSR-1a的表达分别可以在ARC和海马中观察到。结果:Ghrelin或者ARC电刺激可以兴奋海马区的胃牵张敏感神经元。Ghrelin受体拮抗剂[d-Lys-3]-GHRP-6预处理可以完全或者部分阻断这种兴奋作用。海马注射ghrelin可以显著促进胃运动,并且呈现剂量依赖关系,而且这种作用可以被[d-Lys-3]-GHRP-6所阻断。电刺激ARC能够促进胃运动。然而,预处理时[d-Lys-3]-GHRP-6可以减弱这些作用。电损毁海马可以减弱胃运动的兴奋作用,这个作用通过电刺激ARC产生的。结论:通过海马促进胃运动中ghrelin起着重要的作用。ARC可能参与调节海马对胃动力的影响。

Objective： To investigate the growth hormone secretagogue receptor 1A （GHSR-la） expression in the hippocampus; and to explore the influence of ghrelin on hippocampus discharge GD sensitive neurons; explored the neural pathway between ARC and ghrelin neurons in the hippocampus, and the role of ARC in regulating hippocampal and gastric motility in discharge. Methods： The dis- charge ofhippocampus was recorded in vitro and the gastric motility was measured in conscious rats. The expression of GHSR-la in hip- pocampus was detected by PCR Western blot and immunofluorescence histochemical staining. The projection of ghrelin neurons was de- tected by retrograde tracing and immunofluorescence histochemical staining. Ghrelin - double labeled neurons and GHSR-la expression were observed in ARC and hippocampus. Results： Ghrelin or ARC electrical stimulation could stimulate gastric stretch sensitive neurons in hippocampus. Pretreatment with the Ghrelin antagonist [d-Lys- 3]-GHRP-6 can completely or partially block the excitatory effect. Hip- pocampal injection of ghrelin can significantly promote gastric motility, and dose dependently, and this effect can be blocked by [d-Lys-3]- GHRP-6. Electrical stimulation of ARC can promote gastric motility. However, pretreatment with [d-Lys-3]- GHRP-6 can at- tenuate these effects. Electrical damage to the hippocampus can attenuate the gastric motility, which is produced by electrical stimulation of ARC. Conclusion： Ghrelin plays an important role in promoting gastric motility in hippocampus. ARC may be involved in the regula- tion of hippocampal motility.