Role of alpha adrenoceptors in the nucleus accumbens in the control of accumbal noradrenaline efflux: a microdialysis study with freely moving rats
Role of alpha adrenoceptors in the nucleus accumbens in the control of accumbal noradrenaline efflux: a microdialysis study with freely moving rats
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DOI：
10.1007/s00702-007-0745-1
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发表时间：
2007-09-01
影响因子：
3.3
通讯作者：
Cools, A. R.
中科院分区：
文献类型：
--
作者：
Aono, Y.;Saigusa, T.;Cools, A. R.
用微透析技术研究了局部应用α肾上腺素受体激动剂苯肾上腺素和拮抗剂酚妥拉明对自由活动大鼠延髓核（NAc）基础去甲肾上腺素流出量和去甲肾上腺素摄取抑制剂地昔帕明引起的去甲肾上腺素流出量的影响，结果表明，河豚毒素使基础去甲肾上腺素流出量减少72%，而地昔帕明使基础去甲肾上腺素流出量增加204%。苯肾上腺素减少基础去甲肾上腺素流出32%，酚妥拉明阻断这种作用。酚妥拉明使基础去甲肾上腺素外排增加150%，苯肾上腺素抵消了这种作用。去甲肾上腺素流出不受苯肾上腺素的影响，但酚妥拉明增强。地昔帕明抵消了苯肾上腺素的作用，并增强了酚妥拉明的作用。这些结果表明，肾上腺素流出的抑制控制下的α肾上腺素受体，建议是位于突触前的肾上腺素能神经末梢在NAc。此外，这项研究表明，α肾上腺素受体的构象状态不同的可用量的去甲肾上腺素。这些数据的临床影响进行了讨论。
Microdialysis technique was used to study the effects of the locally applied alpha adrenoceptor agonist phenylephrine and antagonist phentolamine on the basal noradrenaline efflux as well as on the noradrenaline uptake inhibitor desipramine-elicited noradrenaline efflux in the nucleus accumbens (NAc) of freely moving rats.Tetrodotoxin reduced basal noradrenaline efflux by 72%, whereas desipramine increased it by 204%. Phenylephrine reduced the basal noradrenaline efflux by 32% and phentolamine blocked this effect. Phentolamine elevated the basal noradrenaline efflux by 150% and phenylephrine counteracted this effect. The desipramine-elicited noradrenaline efflux was not affected by phenylephrine, but enhanced by phentolamine. Desipramine counteracted the effects of phenylephrine and potentiated those of phentolamine.These results indicate that the accumbal noradrenaline efflux is under inhibitory control of alpha adrenoceptors that are suggested to be presynaptically located on adrenergic nerve terminals in the NAc. Furthermore, this study suggests that the conformational state of alpha adrenoceptors varies across the available amount of noradrenaline. The clinical impact of these data is discussed.