Franz D N, Madsen P W, Peterson R G, Sangdee C
Clin Exp Hypertens A. 1982;4(4-5):543-62. doi: 10.3109/10641968209061598.
Despite considerable progress in mapping the central monoaminergic pathways to sympathetic preganglionic neurons in the spinal cord, the respective functional roles of these pathways have not been resolved. Evidence for both excitation and inhibition has been advanced for each of the three monoamines, serotonin, norepinephrine, and epinephrine. Our previous studies on spinal sympathetic pathways to sympathetic preganglionic neurons support the prevailing opinion that serotonin pathways are inhibitory but did not satisfactorily resolve the functional role of the norepinephrine pathways. However, more recent studies showing that intraspinally evoked sympathetic discharges were rapidly and markedly enhanced by phosphodiesterase inhibitors and that this effect was prevented by clonidine have led to formulation of a coherent hypothesis which accommodates much of the conflicting evidence regarding norepinephrine. In addition, evidence for the role of the epinephrine pathways has been obtained by using a selective inhibitor of epinephrine synthesis. The results of these recent studies complement our previous results and suggest that the excitability of sympathetic preganglionic neurons is regulated by excitatory norepinephrine pathways and inhibitory epinephrine pathways that activate or suppress adenylate cyclase to control intraneuronal levels of cyclic AMP.
尽管在绘制脊髓中向交感神经节前神经元投射的中枢单胺能通路方面取得了显著进展，但这些通路各自的功能作用尚未明确。对于三种单胺（5-羟色胺、去甲肾上腺素和肾上腺素）中的每一种，都有兴奋和抑制的相关证据。我们之前对脊髓通向交感神经节前神经元的交感通路的研究支持了一种普遍观点，即5-羟色胺通路具有抑制作用，但未能令人满意地阐明去甲肾上腺素通路的功能作用。然而，最近的研究表明，磷酸二酯酶抑制剂可迅速且显著增强脊髓内诱发的交感神经放电，且可乐定可阻止这种效应，这导致了一个连贯假说的形成，该假说涵盖了许多关于去甲肾上腺素的相互矛盾的证据。此外，通过使用肾上腺素合成的选择性抑制剂，已获得了关于肾上腺素通路作用的证据。这些最新研究结果补充了我们之前的研究结果，并表明交感神经节前神经元的兴奋性受兴奋性去甲肾上腺素通路和抑制性肾上腺素通路的调节，这些通路通过激活或抑制腺苷酸环化酶来控制神经元内的环磷酸腺苷水平。
