南方医科大学学报 ›› 2014, Vol. 34 ›› Issue (12): 1707-.

• •    下一篇

杏仁中央核μ -阿片受体调节大鼠摄食而不是摄水

闫君宝,闫剑群   

  • 出版日期:2014-12-20 发布日期:2014-12-20

μ-opioid receptors in the central nucleus of the amygdala regulate food rather than water intake in rats

  • Online:2014-12-20 Published:2014-12-20

摘要: 目的探讨杏仁中央核内的μ-阿片受体对大鼠摄食和摄水的影响,并评估杏仁中央核内的谷氨酸信号系统在阿片肽介导的
摄食行为过程中的作用。方法将不锈钢套管植入成年雄性SD大鼠一侧的杏仁中央核内,向饱食或脱水后大鼠杏仁中央核内注
射不同剂量的μ-阿片受体选择性激动剂[D-Ala2, N-Me-Phe4, Gly5-ol]-脑啡肽(DAMGO)。注射后60、120和240 min时测量大鼠
的摄食量和摄水量。向饱食后大鼠杏仁中央核内联合注射阿片受体非选择性拮抗剂纳曲酮(naloxone, NTX)和DAMGO,或联
合注射N-甲基-D-天冬氨酸(NMDA)型谷氨酸受体选择性拮抗剂D-AP-5和DAMGO,注射后60、120和240 min时测量大鼠的摄
食量。结果杏仁中央核内注射DAMGO (1~4 nmol)后,饱食大鼠的摄食量明显增加,而脱水大鼠的摄水量变化不大。NTX(26.
5 nmol)可拮抗DAMGO诱导的摄食效应,D-AP-5(6.3~25.4 nmol)则对DAMGO诱导的摄食效应没有影响。结论杏仁中央核
μ-阿片受体参与对大鼠摄食而不是摄水的调节,这种促食欲作用不依赖于杏仁中央核内的NMDA受体的激活。

Abstract: Objective To investigate the effect of μ-opioid receptors (μ-ORs) in the central nucleus of the amygdala (CeA) on
feeding and drinking behaviors in rats and evaluate the role of glutamate signaling in opioid-mediated ingestive behaviors.
Methods Stainless steel cannulas were implanted in the unilateral CeA for microinjection of different doses of the selective
μ-OR agonist DAMGO in satiated or water-deprived male SD rats. The subsequent food intake or water intake of the rats was
measured at 60, 120, and 240 min after the injection. The rats receiving microinjections of naloxone (NTX, a nonselective opioid
antagonist) or D-AP-5 (a selective N-methyl-D-aspartic acid-type glutamate receptor antagonist) prior to DAMGO
microinjection were tested for food intake at 60, 120, and 240 min after the injections. Results Injections of DAMGO (1-4 nmol
in 0.5 μl) into the CeA significantly increased food intake in satiated rats, but did not affect water intake in rats with water
deprivation. NTX (26.5 nmol in 0.5μl) injected into the CeA antagonized DAMGO-induced feeding but D-AP-5 (6.3-25.4 nmol
in 0.5 μl) injections did not produce such an effect. Conclusion μ-ORs in the CeA regulate food intake rather than water intake
in rats, and the orexigenic role of μ-ORs is not dependent on the activation of the NMDAreceptors in the CeA.