Rochette L, Bralet J
J Neural Transm. 1975;37(4):259-67. doi: 10.1007/BF01258653.
The effect of clonidine (0.05 mg/kg i.p.) on 5-hydroxytryptamine (5-HT) turnover has been studied in the whole brain and in various cerebral areas of the rat (brain stem, hypothalamus, striatum and "rest" of the brain). In the whole brain, clonidine produced a significant decrease (-23%) in 5-hydroxyindole acetic acid level and a slight increase (+7%) in 5-HT level. These variations were not observed in all the cerebral structures. The 5-hydroxyindole acetic acid levels were reduced in the hypothalamus and in the rest of the brain; they were not significantly altered in the brain stem and increased in the striatum. The effect of clonidine on the 5-HT synthesis has been studied by evaluation of the rises in 5-HT levels induced by pargyline: these rises were found significantly increased in the brain stem and the hypothalamus and not significantly altered in the other cerebral structures. These findings give support to the hypothesis according to which the norepinephrine receptor stimulation inhibits the activtity in the 5-HT neurons: clonidine reduces primarily the relase of 5-HT without an immediate effect on its synthesis. The differences observed among the various cerebral areas might be explained by the fact that relations between nor-epinephrine and 5-HT neurons do not exist identically in all cerebral structures.
已对可乐定（腹腔注射0.05毫克/千克）对大鼠全脑及不同脑区（脑干、下丘脑、纹状体和脑的“其余部分”）5-羟色胺（5-HT）周转的影响进行了研究。在全脑中，可乐定使5-羟吲哚乙酸水平显著降低（-23%），5-HT水平略有升高（+7%）。并非所有脑结构都出现了这些变化。下丘脑和脑的其余部分中5-羟吲哚乙酸水平降低；脑干中未显著改变，纹状体中升高。通过评估优降宁诱导的5-HT水平升高来研究可乐定对5-HT合成的影响：发现脑干和下丘脑中这些升高显著增加，其他脑结构中未显著改变。这些发现支持了以下假说，即去甲肾上腺素受体刺激会抑制5-HT神经元的活性：可乐定主要降低5-HT的释放，而对其合成无直接影响。不同脑区之间观察到的差异可能是由于去甲肾上腺素与5-HT神经元之间的关系在所有脑结构中并非完全相同这一事实所致。
