Smits R P, Steinbusch H W, Mulder A H
Department of Pharmacology, Free University Medical Faculty, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands.
Neurochem Int. 1988;12(2):193-201. doi: 10.1016/0197-0186(88)90127-1.
Previously it has been shown that radiolabelled histamine is taken up by brain slices and may subsequently be released by depolarizing stimuli in a calcium-dependent manner, indicating the involvement of neurons in uptake and release of histamine. The present study demonstrates that after incubation of brain slices with low (nM) concentrations of [(3)H]histamine the amine may be taken up by (and released from) dopaminergic and serotonergic neurons (nerve terminals). Thus 6-hydroxydopamine- and 5,7-dihydroxytryptamine-induced lesions not only reduced the uptake of [(3)H]dopamine (in striatal slices) and [(3)H]serotonin (in hippocampal slices), but also, though to a lesser extent, that of [(3)H]histamine. Immunocytochemical findings revealed that the neurotoxins did not visibly affect histaminergic neurons. Lesioning of noradrenergic neurons appeared not to alter significantly the uptake of [(3)H]histamine. Further, various drugs acting on either catecholamine-, serotonin- or opioid-receptors and known to cause presynaptic inhibition of the release of [(3)H]dopamine or [(3)H]wrotonin from striatal or hippocampal slices also inhibited [(3)H]histamine release. It is concluded that incubation of brain slices with low concentrations of [(3)H]histamine does not result in a selective labelling of histaminergic neurons. The possibility that, unlike other monoamines, histamine is not subject to high-affinity uptake by the nerve terminals from which it was released, is discussed.
先前的研究表明，放射性标记的组胺可被脑片摄取，随后可能以钙依赖的方式通过去极化刺激释放，这表明神经元参与了组胺的摄取和释放。本研究表明，在用低（纳摩尔）浓度的[³H]组胺孵育脑片后，胺类物质可被多巴胺能和5-羟色胺能神经元（神经末梢）摄取（并释放）。因此，6-羟基多巴胺和5,7-二羟基色胺诱导的损伤不仅降低了[³H]多巴胺（在纹状体切片中）和[³H]5-羟色胺（在海马切片中）的摄取，而且在较小程度上也降低了[³H]组胺的摄取。免疫细胞化学研究结果显示，神经毒素并未明显影响组胺能神经元。去甲肾上腺素能神经元的损伤似乎并未显著改变[³H]组胺的摄取。此外，各种作用于儿茶酚胺、5-羟色胺或阿片受体且已知会引起纹状体或海马切片中[³H]多巴胺或[³H]5-羟色胺释放的突触前抑制的药物，也抑制了[³H]组胺的释放。得出的结论是，用低浓度的[³H]组胺孵育脑片不会导致组胺能神经元的选择性标记。讨论了与其他单胺不同，组胺可能不会被其释放的神经末梢进行高亲和力摄取的可能性。
