Ghrelin在杏仁中央核内对大鼠摄食的调节

The regulation of Ghrelin in the central nucleus of amygdaloid on feeding and its mechanism

目的观察Ghrelin在杏仁中央核(CeA)内对摄食的调节方式,并探讨其可能的作用机制。方法选择雄性SD大鼠48只,行CeA内套管植入术。术后16只大鼠随机分为两组,分别向CeA内注射Ghrelin或生理盐水,检测大鼠1、2、4 h内摄食量;另16只术后大鼠随机分为2组,CeA内分别注射Ghrelin或生理盐水,2 h后用免疫组织化学方法检测大鼠弓状核内c-Fos表达的变化;其余16只术后大鼠随机分为2组,隔夜禁食后,CeA内分别注射Ghrelin的受体(GHS-R)阻断剂D-Lys3-GHRP-6或生理盐水,检测大鼠1、2、4 h内的摄食量。结果大鼠CeA内注射Ghrelin后1、2、4 h内的摄食量明显增加(P<0.05),并使弓状核内c-Fos表达明显增多(P<0.05);隔夜禁食大鼠CeA内注射GHS-R阻断剂D-Lys3-GHRP-6后1、2、4 h内摄食量明显减少(P<0.05)。结论 Ghrelin通过其受体GHS-R在CeA内参与了摄食的调节,其机制可能与弓状核的神经元激活有关。

Objective To examine the effect of Ghrelin in the central nucleus of amygdala（CeA） on feeding and to explore its possible mechanism. Methods 48 SD mail rats were implanted cannula in CeA. The postoperative 16 rats were randomly divided into experi- mental and control groups, the rats were injected with Ghrelin or saline in CeA, the intake of food were detected at 1, 2, 4 h. The other postoperative 16 rats were randomly divided into experimental and control groups, the rats were injected with Ghrelin or saline in CeA, the ex- pression of c-Fos in the arcuate nucleus（ARC） was detected by immunohistoehemical staining method 2 h later. Another postoperative 16 rats were fasted overnight and randomly divided intoexperimental and control groups, the rats were injected with GHS-R antagonist D-Lys3- GHRP-6 or saline in CeA, ＂after 1,2,4 h, the intake of food was detected. Results Administration of ghrelin into the CeA resulted in an in- crease in feeding during 1,2,4 h period post-injection（P 〈0. 05）. The expression of c-Fos in ARC was increased as a consequence of CeA injection of ghrelin（ P 〈 0. 05 ） ; the food intake of overnight fasted rats was significantly decreased during 1, 2,4 h period post-injection of GHS-R Antagonist D-Lys3-GHRP-6 into CeA （ P 〈 0. 05）. Conclusions Ghrelin in CeA is involved in the regulation of food intake through its receptor GHS-R, and its mechanism may be related with the activation of neurons in ARC.