CB1 receptor-mediated control of the release of endocannabinoids (as assessed by microdialysis coupled with LC/MS) in the rat hypothalamus
CB1 receptor-mediated control of the release of endocannabinoids (as assessed by microdialysis coupled with LC/MS) in the rat hypothalamus
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DOI：
10.1111/j.1460-9568.2007.05900.x
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发表时间：
2007-12-01
影响因子：
3.4
通讯作者：
Le Fur, Gerard
中科院分区：
文献类型：
--
作者：
Bequet, Frederic;Uzabiaga, Francoise;Le Fur, Gerard
在目前的研究中，我们研究了大麻素CB1受体在大鼠大脑中内源性大麻素释放的发生和潜在的调节。为此，我们开发了一种高灵敏度(灵敏度极限30-300amol)的新分析方法，将在线脑微透析与固相萃取-液相色谱-串联质谱仪相结合，可以实时检测细胞外液中微量的内源性大麻素。在下丘脑，去极化后局部给予K+，或加或不加钙或谷氨酸，均可刺激去极化后的Anandamine和2-花生四烯酰甘油的释放。全身给药对脂肪酸酰胺水解酶的抑制作用URB597(0.5 mg/kg)可增加AND外流，但不能增加2-花生四烯酰甘油的外流。CB1受体拮抗剂利莫那班(10 mg/kg i.p.)CB1激动剂WIN55,212-2(2.5 mg/kg ip.)减少，安非他明的释放。有趣的是，相同的处理引起了相反的变化，2-花生四烯基甘油的释放。利莫那班在3 mg/kg i.p.3 mg/kg时完全拮抗WIN55、212-2(2.5 mg/kg i.p.)的作用。综上所述，这些结果表明，CB1受体能够通过反馈机制控制下丘脑内源性大麻素的局部释放，并加强了Anandide和2-花生四烯酸甘油具有不同的生理作用的观点。
In the present study, we examined the occurrence and potential regulation of endocannabinoid release by cannabinoid CB1 receptors in the rat brain. To this end, we developed a highly sensitive (limit of sensitivity 30-300 amol) new analytical method, combining online brain microdialysis with solid-phase extraction-liquid chromatography-tandem mass spectrometry, which allowed the detection in real time of trace amounts of endocannabinoids in the extracellular fluid. In the hypothalamus, anandamide and 2-arachidonoyl-glycerol release was stimulated following depolarization via local administration of K+, with or without addition of Ca2+, or glutamate application. Inhibition of fatty acid amide hydrolase by systemic administration of intraperitoneal (i.p.) URB597 (0.5 mg/kg) induced an increase of anandamide, but not 2-arachidonoyl-glycerol, outflow. The CB1 receptor antagonist rimonabant (10 mg/kg i.p.) increased, whereas the CB1 agonist WIN55,212-2 (2.5 mg/kg i.p.) decreased, anandamide release. Interestingly, the same treatments induced opposite changes in 2-arachidonoyl-glycerol release. At a dose of 3 mg/kg i.p., which by itself did not affect endocannabinoid release, rimonabant fully antagonized the effect of WIN55,212-2 (2.5 mg/kg i.p.). Taken together, these results suggest that CB1 receptors are able to control the local release of endocannabinoids in the hypothalamus via a feedback mechanism and strengthen the view that anandamide and 2-arachidonoyl-glycerol have distinct physiological roles.