Adell A, Carceller A, Artigas F
Department of Neurochemistry, CSIC, Barcelona, Spain.
J Neurochem. 1993 May;60(5):1673-81. doi: 10.1111/j.1471-4159.1993.tb13390.x.
The characteristics of the serotonin (5-HT) output in the dorsal and median raphe nuclei of the rat were studies using in vivo microdialysis. The basal output of 5-HT increased after KCl was added to the perfusion fluid. In contrast, neither the omission of calcium ions nor the addition of 0.5 microM tetrodotoxin affected dialysate 5-HT or 5-hydroxyindoleacetic acid (5-HIAA). Reserpine did not decrease the output of 5-HT and 5-HIAA 24 h later and p-chloroamphetamine increased 5-HT in both vehicle- and reserpine-treated rats severalfold. 8-Hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), at 1 or 10 microM, perfused into the raphe did not change the outputs of 5-HT or 5-HIAA. Higher doses (0.1, 1, and 10 mM) increased extracellular 5-HT in the raphe, probably via an inhibition of uptake. In animals bearing two probes (raphe nuclei and ventral hippocampus), only the 10 mM dose of 8-OH-DPAT perfused into the raphe decreased the hippocampal output of 5-HT and 5-HIAA. The systemic injection of 0.1 mg/kg 8-OH-DPAT decreased dialysate 5-HT and 5-HIAA in the raphe and hippocampus. These results suggest that extracellular 5-HT in raphe nuclei originates from a cytoplasmic pool and is not dependent on either nerve impulse of 5-HT neurons or local activation of 5-HT1A receptors.
采用体内微透析技术研究了大鼠中缝背核和中缝正中核中5-羟色胺（5-HT）的释放特性。向灌流液中加入氯化钾后，5-HT的基础释放量增加。相反，无论是去除钙离子还是加入0.5微摩尔的河豚毒素，都不会影响透析液中5-HT或5-羟吲哚乙酸（5-HIAA）的含量。利血平在24小时后并没有降低5-HT和5-HIAA的释放量，对氯苯丙胺在给予溶剂和利血平处理的大鼠中均使5-HT增加了数倍。向中缝核灌注1或10微摩尔的8-羟基-2-（二正丙基氨基）四氢萘（8-OH-DPAT）不会改变5-HT或5-HIAA的释放量。更高剂量（0.1、1和10毫摩尔）可增加中缝核细胞外5-HT的含量，可能是通过抑制摄取实现的。在植入两个探针（中缝核和腹侧海马体）的动物中，只有向中缝核灌注10毫摩尔剂量的8-OH-DPAT会降低海马体中5-HT和5-HIAA的释放量。全身注射0.1毫克/千克的8-OH-DPAT可降低中缝核和海马体中透析液中5-HT和5-HIAA的含量。这些结果表明，中缝核中的细胞外5-HT来源于细胞质池，不依赖于5-HT能神经元的神经冲动或5-HT1A受体的局部激活。
