Attenuation of morphine withdrawal signs by muscimol in the locus coeruleus of rats
Attenuation of morphine withdrawal signs by muscimol in the locus coeruleus of rats
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DOI：
10.1097/fbp.0b013e3282fe8849
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发表时间：
2008-05-01
影响因子：
1.6
通讯作者：
Ghasemi, Tayeb
中科院分区：
文献类型：
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作者：
Mirzaii-Dizgah, Iraj;Karimian, Seyed Morteza;Ghasemi, Tayeb
本研究探讨了蓝斑内注射γ-氨基丁酸A型（GABA（A））受体激动剂对吗啡依赖大鼠纳洛酮戒断症状的影响。评估了20种不同的戒断体征。计算总戒断评分并用作戒断强度的指数。分别在注射纳洛酮前15和30 min注射γ-氨基丁酸激动剂和拮抗剂。蝇蕈醇，一种GABAA激动剂（25、50和100 ng/部位），以剂量非依赖性方式降低总戒断评分，而荷包牡丹碱（0.367、3.67和36.7 ng/部位），一种GABAA拮抗剂，和CGP 35348（48.6 ng/部位），一种γ-氨基丁酸B型拮抗剂，单独使用没有影响。另一方面，蝇蕈醇的作用被CG P35348（48.6 ng/部位）逆转，但不被荷包牡丹碱（36.7 ng/部位）逆转。由此可以得出结论，蝇蕈醇的作用被γ-氨基丁酸B型拮抗，但不被GABAA受体拮抗剂拮抗。所涉及的机制似乎错综复杂，需要进一步研究。
This study examined the effects of intra-locus coeruleus injection of a gamma-amino-butyric acid type A (GABA(A)) receptor agonist on naloxone-induced withdrawal signs of morphine-dependent rats. Twenty different withdrawal signs were assessed. The total withdrawal score was calculated and used as an index of withdrawal intensity. The gamma-amino-butyric acid agonist and antagonists were injected 15 and 30 min before naloxone injection, respectively. Muscimol, a GABAA agonist (25, 50, and 100 ng/site), decreased the total withdrawal score in a dose-independent manner, whereas bicuculline (0.367, 3.67, and 36.7ng/site), a GABAA antagonist, and CGP35348 (48.6 ng/site), a gamma-amino-butyric acid type B antagonist, alone had no effects. On the other hand, muscimol effects were reversed by CG P35348 (48.6 ng/site) but not by bicuculline (36.7 ng/site). It may be concluded that the effects of muscimol were antagonized by gamma-amino-butyric acid type B but not by GABAA receptor antagonists. The mechanism involved seems to be intricate and needs further study.