Mataga N, Imamura K, Watanabe Y
Department of Neuroscience, Osaka Bioscience Institute, Japan.
Brain Res. 1991 Jun 14;551(1-2):64-71. doi: 10.1016/0006-8993(91)90914-h.
The effect of 6R-tetrahydrobiopterin (R-THBP) on neurotransmitter release was investigated using in vivo brain microdialysis in urethane-anesthetized rats. Perfusion of 1.0 mM R-THBP enhanced the level of dopamine output in dialysates collected from the striatum and frontal cortex. R-THBP perfusion also increased serotonin (striatum) and glutamate outputs (striatum and frontal cortex). Dopaminergic terminals in the striatum were destroyed unilaterally by continuous infusion of 6-hydroxydopamine (6-OHDA) using an osmotic minipump system. The effect of R-THBP administration on glutamate level was found to be almost completely suppressed in the 6-OHDA-lesioned side of striatum, while in the intact side of striatum the glutamate level in the dialysates responded normally to R-THBP perfusion. These results suggest that R-THBP may play a role in the mechanisms of release of dopamine, serotonin, and glutamate. The functioning of the catecholaminergic system probably mediates the increase in glutamate output due to R-THBP perfusion.
使用体内脑微透析技术，在乌拉坦麻醉的大鼠中研究了6R-四氢生物蝶呤（R-THBP）对神经递质释放的影响。灌注1.0 mM R-THBP可提高从纹状体和额叶皮质收集的透析液中多巴胺的输出水平。R-THBP灌注还增加了血清素（纹状体）和谷氨酸输出（纹状体和额叶皮质）。使用渗透微型泵系统通过连续输注6-羟基多巴胺（6-OHDA）单侧破坏纹状体中的多巴胺能终末。发现给予R-THBP对谷氨酸水平的影响在纹状体的6-OHDA损伤侧几乎完全被抑制，而在纹状体的完整侧，透析液中的谷氨酸水平对R-THBP灌注正常反应。这些结果表明R-THBP可能在多巴胺、血清素和谷氨酸的释放机制中起作用。儿茶酚胺能系统的功能可能介导了由于R-THBP灌注导致的谷氨酸输出增加。
